Simultaneous Determination of Low Molecule Benzotriazoles and Benzotriazole UV Stabilizers in Wastewater by Ultrasound-Assisted Emulsification Microextraction Followed by GC-MS Detection

Simultaneous Determination of Low Molecule Benzotriazoles and Benzotriazole UV Stabilizers in Wastewater by Ultrasound-Assisted Emulsification Microextraction Followed by GC-MS Detection | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Simultaneous Determination of Low Molecule Benzotriazoles and Benzotriazole UV Stabilizers in Wastewater by Ultrasound-Assisted Emulsification Microextraction Followed by GC-MS Detection Kotowska Urszula, Struk-Sokołowska Joanna, Piekutin Janina This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-263795/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 9 You are reading this latest preprint version Abstract A rapid, sensitive, economically and ecologically friendly method based on one-step ultrasound-assisted emulsification microextraction (USAEME) and in situ derivatization followed by gas chromatography-mass spectrometry (GC-MS) for simultaneous determination of low molecular benzotriazoles (LMBTs) and benzotriazole-based ultraviolet filters (BUVs) was developed. The optimized method allow quantification of benzotriazole (BT), 4-methylbenzotriazole (4MBT), 5-methylbenzotriazole (5MBT); 5-chlorobenzotriazole (5ClBT), 2-(2′-hydroxy-3′-tert-butyl-5′-methylphenyl)-5-chlorobenzortriazole (UV326) and 2-(2′-hydroxy-5′-(1,1,3,3-tetramethylbutyl)phenyl)benzotriazole (UV329) in municipal and industrial (dairy) wastewater. The method was validated using real influent and effluent wastewater and samples at various stages of the purification process. Obtained relative recoveries were between 77 and 137%, limits of detection (LoDs) from 0.001 to 0.035 µg/L, the repeatability expressed by the coefficient of variation (CV) did not exceed 12%. The use of the method for the determination of the tested compounds in municipal and industrial wastewater showed their presence in most of the tested samples, in concentrations from LoD to 6.11 µg/L. The conducted studies of samples from municipal wastewater treatment plant (WWTP) located in north-eastern Poland showed that the effectiveness of benzotriazole removal by this plant is from 29 to 84%. The load of tested compounds released into the environment by this facility ranges from 2 to 269 mg/day/1000 inhabitants. Analytical Chemistry General Biochemistry Environmental Chemistry Benzotriazoles Municipal wastewater Dairy wastewater Ultrasound-assisted emulsification microextraction Removal efficiency Mass loads Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction The presence of organic micropollutants in various elements of the environment is a major problem, as these compounds can pose a significant threat to living organisms or entire ecosystems. Its presence is caused by rapid industrial and technological development 1 . Benzotriazole (BT) and its derivatives are high-production-volume chemicals, and reports on their toxicity require careful assessment of their distribution in the environment 2 . Micropollutants from the BT group are formed as a combination of benzene and triazole particles. This structure is susceptible to a number of multiple reactions, resulting in a large number of derivatives. LMBTs are polar compounds and have good solubility in water 3 . The pK a values of LMBTs are between 7.9 to 9.0. A solution of LMBT has a slightly acidic reaction. They tend to be non-ionic at neutral pH 4 . Benzotriazole acts as an electron donor or precursor to radicals or carboanions. It is easily introduced into other chemical structures through a number of reactions such as condensation or addition 5 . The values of the octanol-water partition coefficient are 1.4 for BT and 1.7 for metylobenzotriazoles. Their properties also include considerable resistance to oxidation and biodegradation 6 . Therefore benzotriazoles are only partialy removed by activated sludge and other treatment processes such as chlorination and advanced oxidation 7 . BTs can form stable and durable complexes with metals, resulting in a protective layer on the metal surface. Anti-corrosion properties have particles containing in their structure a hydrogen atom in position 1 and compounds with methyl group, especially 5MBT and 4MBT. BTs can be used as solder, brass, steel, cast iron and aluminium protection agents and are used in heating systems 3 . Phenyl group of benzotriazoles, especially in position 2, absorb UV light in the wavelength range 300 to 400 nm. There is a large group of compounds containing a benzotriazole moiety used to stabilise against UV radiation 8 . BUVs protect against degradation and yellowing of products. They are used in the production of paints, films, plastics, coatings and are components of skin care products 9 , 10 . BT and its derivatives are a component of detergents, including dishwasher tablets and powder. Benzotriazoles are a component of antifreeze agents and de-icing agents. Antifreeze mixtures for various surfaces (roads, airports, car parks) are now widespread and widely used. As a result, the risk of BTs entering the environment from the above mentioned source is very high 11 . BT derivatives are widely used in the pharmaceutical industry. They are also additives in petroleum products. One of the main objectives of using these compounds is to increase the efficiency and durability of products 2 . The biological activity of many BT derivatives and its durability in the environment is connected with observed negative impact on the aquatic and terrestrial organisms 12 . These compounds are classified as hazardous to the environment and causing long-term harmful effects 13 . Benzotriazoles can be absorbed by inhaling the aerosol and by ingestion 14 . Toxicological studies have shown that benzotriazoles have mutagenic and toxic effects on some microorganisms, including algae and also plants 15 , 16 . BTs can inhibit the growth of bacteria and weaken their ability to degrade certain organic compounds, leading to impairment of the self-purification process when these compounds enter the river from a wastewater treatment plant 4 . The BTs have been shown to be genotoxic and may disrupt hormonal management 17 . BT at higher concentrations showed antagonistic interaction with the androgenic receptor and potential disruption of the thyroid hormone system and fatty acid metabolism 18 . It has been proven that 1H-benzotriazole has carcinogenic properties for humans. According to Shi et al. 4 benzotriazoles are associated with the development of endometrial cancer. Toxicity studies have shown that direct contact with some widely used BUVs can cause inflammation and skin irritation. Gender-related hematological and histopathological changes in the liver, kidneys, spleen and thyroid glands were observed after long-term toxicity testing of 2-(3,5-di-tert-butyl-2-hydroxyphenyl) benzotriazole (UV-320) in rats. Similar properties were also shown for 2-(3,5-di-tertert-butyl-2-hydroxyphenyl) benzotriazole (UV-328) 19 . Some BUVs were also found to have similar estrogenic effects to those shown by the natural sex hormone 17-β-estradiol 20 . BTs are fourt most aboundant aquatic contaminants, after ethylenediamine tetraacetic acid and its salts, nitrilotriacetic acid, and alkylbenzene sulfonates 21 . Their annual consumption in the United States alone exceeds 9,000 tons, it can also be presumed that it is very high in all developed economies 22 , 23 . Quantification of benzotriazoles and its derivatives in environmental samples is carried out mainly by chromatographic methods, although the literature describes the use of electrochemical and spectrophotometric methods for this purpose 24 , 25 . High-performance or ultra-high-performance liquid chromatography (HPLC, UHPLC) is usually used to determine BTs in the environmental and in biological samples. Detection is carried out using UV spectrophotometr, diode array detector (DAD), or mass spectrometer (MS) 19,26−29 . The greatest sensitivity and selectivity of the determinations was achieved using UHPLC with tandem MS detector of triple quadrupole (QqQ MS/MS) or electrospray ionization (ESI MS/MS) configuration 30 . Determination of highly polar low mass compounds from the group of BT derivatives by GC requires the use of polar stationary phases or the conversion of compounds to less polar and more volatile derivatives, for example by acetylation or methylation 6,13,20,31−33 . Less polar BT derivatives such as BUVSs can be analyzed by GC on standard medium polar columns without a derivatization process 22 , 34 . MSs with electron ionization (EI) and a quadrupole (Q) or a time-of-flight (ToF) analyzers as well as tandem mass spectrometers (MS/MS) were used as GC detectors. Undoubtedly, the isolation and enrichment of samples is a key step in a correct analytical procedure for the determination of trace contaminants in a complex matrix. Wastewaters contain many chemical compounds, often with similar properties, and with a large variation in composition over time. A solid phase extraction (SPE) technique is usually used to extract benzotriazoles from aqueous samples 16 , 28 , 35 . In recent years, microextraction techniques have become more and more important in environmental analysis, including benzotriazole analysis. Ahmad et al. described the use of bar adsorptive microextraction (BAME) to isolate BT and 5MBT from rain, tap, estuarine waters as well as wastewater 29 . Dispersive liquid-liquid microextraction (DLLME) was used for isolation of low molecule benzotriazoles in water samples 33 . Lu et al. proposed the use of air assisted liquid-liquid microextraction (AALLME) in the procedure for the determination of BT, 5MBT and 5ClBT in aqueous samples 26 . The aim of presented work was the development of a simple methodology based on ultrasound assisted emulsification microextraction (USAEME) with in-situ derivatization and GC-MS for simultaneous determination four LMBTs: BT, 4MBT, 5MBT, and 5ClBT as well as two BUVs: UV 326 and UV329 in wastewater. The USAEME technique described for the first time by Requeiro et al. is isolation technique based on the emulsification of a microliter volume of organic solvent in aquous sample by ultrasound radiation and separation of both phases by centrifugation 36 . The literature review shows that so far USAEME has not been used for determination of BTs in any matrix, and no liquid-liquid microextraction has ever been used in the determination of the BUVs in any samples. Wastewater samples taken from municipal and industrial WWTPs collected at various stages of the technological process have been analyzed. The effectiveness of the BTs removal processes in individual tested unit as well as its mass loads was also determined. Results And Discussion Optimization of the extraction and derivatization procedure Very few procedures for the determination of benzotriazoles by GC in combination with single quadrupole MS have been published 23,31,33,35,37 . Based on previous literature reports, an acetylation reaction was selected for the derivatization of BTs in this work, which was carried out simultaneously with the extraction process. A careful impact analysis has been carried out for the following process conditions: the type and volume of the extraction solvent, the volume of acetic anhydride (derivatization reagent), the addition of a buffer salt and the time of simultaneous extraction and derivatization. n -Hexadecane, 1-undecanol, chloroform, carbon tetrachloride, toluene and chlorobenzene were tested as potential extraction solvents. The characteristics of selected solvents are included in Table S1 (Supplementary Material). The responses obtained for each analyzed compound when different solvents were used for extraction are shown in Fig. 1A. The volume of each of the solvents used for the extraction was 100 µL. Optimization was performed for milli-Q water to which a mixture of analytes was introduced, with a concentration of 10 µg/L each. Other conditions of the process were as follows: 100 µL of acetic anhydride, five minutes extraction time. The same conditions were used in all optimization experiments unless otherwise stated. Chlorinated solvents with a density greater than that of water were selected for the tests (see Table S1, Supplementary Material), enabling easy removal of the organic layer after extraction by using test tubes with a conical bottom 36 . n -Hexadecane and 1-undecanol make it possible to separate from the aqueous solution after extraction by solidifying a floating solvent drop, due to the corresponding melting points, which are 18 o C and 13 o C, respectively 38 . Aromatic solvents were selected due to their structural similarity to analytes and the possibility of forming π-π interactions, which may positively affect the extraction efficiency 33 . As expected, the highest extraction efficiency was achieved with the use of chlorobenzene and toluene, while the area of the chromatographic peaks recorded when the extractant was chlorobenzene was 13 to 22% higher than in the case of toluene. It can also be seen that for chlorobenzene, the lowest standard deviations of the recorded peak areas were recorded. When making the selection, the toxicity of solvents was also taken into account, which was against the chlorobenzene. In contrast, the toxicity of chlorobenzene is lower than that of other organochlorine solvents used in microextraction techniques. The use of toluene as the extractant requires additional operations to separate it from the extracted matrix. Moving to other vessels for this purpose is associated with the risk of losing some of the solvent or recontaminating the sample. At the same time, all additional operations increase the exposure of the analyst and the environment to the contact with the solvent. Taking all the above into account, chlorobenzene was selected as the optimal solvent for the extraction. Optimal solvent volume was selected on the basis of tests performed at 40, 60 and 80 µL. The results of the conducted experiments are presented in Fig. 1B. As expected, there was clearly an inverse relationship between the volume of the solvent and the area of the obtained analyte peaks. Therefore, it was found that the volume of 40 µ L is optimal for the conducted experiments. The solubility of chlorobenzene in water is approximately 500 mg/L, so the theoretical amount of solvent that can be recovered after extracting a 5 mL water sample is 37.5 µL. After extraction, it was possible to collect about 25 µL of chlorobenzene, which made it possible to carry out several replications of the analysis using the autosampler of the GC-MS device. In order to make sure that the determined optimal volume could be used during the wastewater analysis, additional experiments were carried out using influents as well as the wastewater from different treatment stages. For influents, it was found necessary to use a solvent volume of 80 µL to obtain 15-20 µL of extract that could be analyzed by GC-MS. It is related to the presence of a rich matrix in wastewater, including macromolecular compounds (proteins, fats and carbohydrates), i.e. substances with emulsifying properties, increasing the solubility of chlorobenzene 39 . Therefore, it was decided to use a volume of solvent equal to 80 µL in all subsequent experiments. However, when the developed method will be used for samples of less polluted water, including surface water, groundwater, and purified sewage, it is possible to use a chlorobenzene volume of 40 µL. The optimization results for acetic anhydride volume, ionic strength and extraction time are shown in Fig. 2. The effect of acetic anhydride volume on the extraction efficiency was investigated in the range from 60 to 250 µL and 125 µL was selected as optimal. It turned out to be sufficient also when the experiments were repeated with samples of raw sewage enriched with analytes at a concentration of 100 µg/L. Many studies have been carried out and described in the literature on the selection of the appropriate salt or buffer solution for liquid-liquid microextraction 36,40 . As a result, it was found that the optimal choice in this case are phosphoric (V) acid salts with buffering properties. In microextraction methods, especially in USAEME, the use of sodium bicarbonate is disadvantageous because the formation of CO 2 bubbles makes it difficult to separate the extract from the aqueous matrix 41 . However, the influence of the ionic strength on the process of benzotriazole microextraction is unclear, as the available literature gives completely opposite findings 26,33 . In this study, the effect of salt addition ranging from 0 to 10% was investigated. The obtained results do not show an unequivocal relationship between the obtained analyte peak areas and salt concentration. Similar results were obtained for concentrations of 0, 2.5 and 5%. In the case of concentrations of 7.5 and 10%, higher peak areas were obtained for BT and 4MBT, and lower for 5MBT. In order to definitively settle this issue, the research was repeated for 0 and 10% concentrations with the use of influent wastewater with addition of benzotriazoles. Studies have shown that in the case of a very complex matrix, which is untreated wastewater, the addition of buffering salt causes precipitation during extraction, which makes it difficult to take the appropriate volume of extract. Therefore, in further works, no salt was added to the extracted matrix. A similar solution was selected as optimal also when using the DLLME technique 33 . The relationship between the time of simultaneous extraction and derivatization, and the extraction efficiency was studied in the range of three to 12 minutes. Extending the simultaneous extraction and derivatization time from 3 to 5 minutes results in an increase in surface areas by about 10%. The surface areas obtained after 12 minutes of the process, for all tested compounds, were about 30% lower than those obtained after 5 minutes. The decrease in analyte surface areas with the extension of sonication time indicates that acetyl derivatives of benzotriazoles are likely to partially hydrolyze to free forms upon prolonged contact with the aqueous phase. This phenomenon has already been observed in the case of other polar compounds 38 . Method validation Analytical parameters including linearity, precission, LoD, and limit of quantification (LoQ) as well as method recovery were investigated under established optimal conditions. Calibration curves were obtained by spiking the ultrapure water with seven concentration levels, between 0.05 and 10 µg/L and performing the extraction and GC-MS analysis. In the case of 5ClBT two chromatographic peaks were recorded. This situation is probably related to the formation of two isomeric acetyl derivatives of 5ClBT, substituted at the 1 and 3 positions of the triazole ring 42 . Calibration curves for this compound were plotted and validation parameters were determined based on peak 1, peak 2 and the sum of the peaks. The validation data are summarized in Table 1 . Calibration curves were linear within the studied concentration ranges with coefficients of determination (r 2 ) ≥ 0.9900 for all target compounds. The LoD was established as the concentration giving a signal-to-noise ratio (S/N ratio) of 3 and it was measured in chromatograms registered for the solutions with lowest analytes concentration. The LoQ was calculated as the concentration corresponding to an S/N ratio of 10. LoDs and LoQs values for the tested benzotriazoles ranged from 0.1 to 1.8 ng/L and from 0.4 to 5.9 ng/L, respectively. The lowest detection and quantification limits were recorded for UV326, UV329 and 5MBT. The precision of the determinations was established on the basis of CV calculated for developed model (calibration curve). The CV for each point was calculated as the ratio of the root mean squared error to the mean of the concentration calculated on the basis of the model 43 . The CV given in Table 1 was calculated as the average percent value of the variance coefficients determined for seven points of the calibration curves. For the individual compounds tested, mean CV values ranging from 4.7 to 9.8% were obtained. As expected, the measurements for higher concentrations are characterized by the highest precision. The mean CV value for all tested compounds at a concentration of 10 µg/L was 4.7%, while for the concentration of 0.05 µg/L it was almost 15%. Recoveries for each compound were determined at two concentration levels: 0.2 and 2 µg/L. They were calculated comparing nominal concentration with the value determined based on the calibration curve. The recovery values were between 81 and 116% for the lower concentration, and between 87 1nd 118% for the higher value. Matrix effect Municipal and industrial wastewater are water matrices with a high degree of pollution and properties strongly differing from those of pure water. A complicated matrix may affect the surface area of the obtained analytical signals as well as the location and course of the baseline. It is assumed that the influence of the matrix at the level of -20 to 20% is considered acceptable and determinations can be made on the basis of a calibration performed on a simplified matrix. With stronger disturbances, matrix-matched calibration must be used 44 . The tests of the resistance of the method showed that the discrepancies of the received signals exceed the determined range. The highest exceedances were recorded when the matrix was influents. Therefore, the developed method was validated with the use of six different real matrices (see Table S2 and Table S3, Supplementary Material). For all municipal wastewater matrix, good linearity was obtained, expressed as r 2 value above 0.99. The mean recovery deviation from the value of 100% was the highest for influent wastewater and was approximately 18%. In the case of the remaining matrices, it ranged from 8 to 13%, i.e. it did not differ significantly from the values determined for water. The CV values did not exceed 10%. It was probably influenced by the higher concentrations within the curve. The average sensitivity of determinations for the group of the target compounds, expressed by the LoD value, in the case of municipal wastewater as matrices, ranged from 6 to 14 ng/L. In the case of industrial wastewater as a sample matrix, the deviation of validation parameters from those registered for water is higher than in the case of municipal wastewater. In this case, average values of the difference in recovery from 100% equals 25% for influents and 12% for wastewater after flotation. Higher values of CV, and LoD were also recorded. It can be seen that the deterioration of the recovery and the reduction of sensitivity, is quite well correlated with the contamination of the matrix used, expressed by the BOD, COD, suspension, nitrogen and phosphorus concentrations (see Tables S4, S5, S6 Supplementary material). Comparison with other analytical procedures Due to its high polarity and limited volatility, liquid chromatography is the most commonly used in BTs analysis, usually combined with MS or MS/MS detection. The limited availability of this type of equipment as well as the high cost of determinations and large production of waste solvents are significant obstacles of LC-MS/MS technique. GC-MS systems, especially those with one quadrupole, are currently common equipment in laboratories conducting environmental determinations. At the same time, GC-MS analyzes are cost-friendly, easy to perform and environmentally friendly due to the small amount of waste generated. The development of derivatization in the matrix in recent years facilitated the use of GC in the analysis of compounds even with high polarity. Table 2 presents a comparison of the developed method with other solutions used in the determination of BTs. Due to the fact that in the literature from recent years there are comparisons of BTs determination methods, only procedures based on gas chromatography and various isolation techniques were taken into account 22,26,29 . Comparing the developed procedure with others described in the literature, it can be stated that the validation parameters determined by us are similar or better than in the case of other determinations performed with the GC-MS and GC-MS/MS techniques. The comparison of isolation techniques shows that SPE, DLLME and USAEME allow determinations with similar accuracy, precision and sensitivity, while the use of SPME is associated with the deterioration of the validation parameters of the procedure. It should be emphasized, however, that the procedures based on the use of SPE are multi-stage (conditioning of columns, sample application, elution, concentration of the eluate) and require a large volume of samples (even 2.5 L, on average 1L) and the use of large volumes of organic solvents (up to 61 mL per one repetition of the procedure) 23 . These facts justify the growing popularity of liquid-liquid microextraction techniques. The DLLME-GC-MS and USAEME-GC-MS procedures have similar analytical characteristics (with a slight advantage of the first technique), while the 20 times higher consumption of organic solvents in the DLLME technique (sum of the extraction and dispersion solvent volumes) should be considered as an advantage of USAEME. A significant improvement of the proposed method, compared to the DLLME-based procedure, is the simple, one-step recovery of the solvent after extraction, which is associated with a lower risk of sample contamination and analyte loss 33 . Wastewater analysis The developed USAEME-GC-MS procedure was used for the simultaneous determination of compounds from the LMBT and BUV groups in wastewater from two municipal wastewater treatment plants and in the outflow of MPP. Fig. 3 show chromatograms recorded for the influent and effluent wastewater from WWTP A. Table 3 summarizes the concentrations of the target LMBTs and BUVs in samples of municipal wastewater from WWTP A and WWTP B and in dairy wastewater from MPP. BT, 4MBT and 5MBT determinations were performed on six samples of municipal influents and six samples of effluents (five from WWTP A and one from WWTP B). 5ClBT, UV326, and UV329 determinations were carried out in four samples of each type from WWTP A. Average concentrations of LMBTs in influent wastewater, along with deviations, ranged from 0.055±0.007 µg/L for 5ClBT (N=2, two values below the LOD) to 2.205±2.335 µg/L for BT. Among the methyl derivatives of BT, the higher concentration of 1.117±2.058 µg/L was recorded for 4MBT and for 5MBT it was 0.158±0.136 µg/L. For BUVs, the mean concentrations in municipal influents were 0.190±0.082 µg/L and 0.167±0.038 µg/L for UV326 and UV329, respectively (N = 3, one value below LOD). In the treated wastewater, the average concentrations of BT (N=6), 4MBT (N=6), 5MBT (N=4) and 5ClBT (N=2) were 1.065±0.907 µg/L, 0.150±0.171 µg/L, 0.178±0.215 µg/L, and 0.010 µg/L, respectively. The mean concentrations of UV326 (N=3) and UV329 (N=2) were 0.040±0.036 µg/L and 0.050±0.028 µg/L, respectively. The LMBTs content in municipal influents determined in this study is similar to the values obtained during the research conducted in Spain by Dominguez et al. 31 . Other results that can be found in the literature indicate a higher content of these compounds, reaching 13 µg/L for BT and over 7 µg/L for other LMBTs 22,45,46 . The content of LMBTs in municipal effluents similar to that recorded by us was obtained by Liu et al. and Casado et al. for samples from Australia and Spain 22,33,34 . The remaining literature reports give higher concentrations of these compounds in effluents, reaching 10 µg/L 45 . The content of BUVs in municipal influents reported in the literature is over ten times higher than the values recorded by us 34 . Fig. 4 shows the range and mean ML of target compounds flowing with influents into WWTP A and introduced with effluents from WWTP A into the aquatic environment. Fig. 5 shows the range and average values of the removal efficiency (RE) of individual compounds in the WWTP A. When no compound was detected in a specific matrix, the appropriate LOD value was inserted into the calculation of ML and RE. The ML values for each target compound was estimated according to Eq. (1). The average ML values calculated for influents ranged from approximately 8 mg/day/1000 inhabitants for 5ClBT to almost 600 mg/day/1000 inhabitants for BT. For the remaining compounds, these values were at the level of several dozen mg/day/1000. The lowest mass load introduced into the environment was recorded for 5ClBT and it was 2.2 mg/day/1000 inhabitants. 269 mg/day/1000 inhabitants was the ML for BT, which was the highest recorded value. The average ML value for the remaining compounds ranged from a few to several mg/day/1000 inhabitants. Efficiency (RE, %) of the removal of LMBTs and BUVs during the treatment process depends on its tendency to be absorbed by activated sludge as well as its biodegradability and physiochemical properties (volatility, polarity, water solubility). RE is defined as negative or low when RE < 20%, moderate when the RE ranged between 20.1% and 70% and high when the RE exceeded 70.1% 47 . As shown in Fig. 5, the average RE value obtained for target compounds allows the removal efficiency of BT, 4MBT and 5MBT to be classified as moderate and 5ClBT, UV326, and UV329 as high. In the case of BT, 4MBT, 5MBT, in some sampling campaigns higher concentrations were observed in effluents than in influents, i.e. RE values below zero were obtained. “Negative removal” has been previously observed and it could be explained by the varying sorption of the target compounds in activated sludge and their subsequent desorption by successive portions of wastewater 48 . The reason may also be the fact that the influents and effluents were collected at the same time, while the treatment process in WWTP A takes about 48 hours, so the effluents come from a completely different portion of influents than taken on a given day 49 . On the basis of the obtained results it can be concluded that the removal of BTs by activated sludge processes is not sufficient and it is advisable to use additional technologies as the tertiary wastewater treatment. Methods Chemicals and solutions Analytes: BT, 4MBT, 5MBT on the purity of analytical standards were purchased from Supelco, Germany, and 5ClBT, UV326 and UV329 of the purity not less than 99% was obtained from Sigma-Aldrich, Germany. Most solvents: methanol, chloroform, carbon tetrachloride, acetone, chlorobenzene, toluene as well as anhydrous disodium hydrogen phosphate (V) (buffering salt) were purchased from POCH (Poland). Acetic anhydride (V) were provided by Chempur (Poland). Other solvents: 1-undecanol and n -hexadecane were obtained from Sigma-Aldrich, Germany. The standards were individually dissolved in methanol to obtain concentrations at 1 mg/mL. So prepared stock solutions were stored at –20 o C not longer than two weeks. Working solutions were prepared by diluting the stock standard solution in methanol and stored at –20 o C not longer than for two weeks. Deionized water was obtained using a purification system (Milli-Q RG, Millipore, USA) and was stored in glass bottles. Wastewater samples Average daily municipal wastewater samples were obtained from municipal wastewater treatment plants (WWTP) located in two cities in the north-east Poland. Treatment processes used by WWTPs include mechanical purification (such as grates, sieves, sand traps, settling tanks and grease separators) as well as biological purification through the use of activated sludge with no tertiary treatment. After the completion of treatment processes effluents are discharged into local rivers belonging to the catchment area of the Vistula River which is a part of the Baltic Sea drainage basin. The WWTP A is located in the city with a population of 300,000. Daily capacity of the WWTP A equals 100,000 m 3 /day. It’s average processing is approximately 70.000 m 3 /day. The work of the plant is based on active sludge technology (flow system) assuming the load of BOD 5 equal to 30.000 kg O 2 /day, suspension load of 55,000 kg/day, total Kjeldahl nitrogen 6,000 kg/day, and total phosphorus 850 kg/day. Treatment efficiency meets the effluent standards required by Polish legislation for a plant of this size. Average parameters of raw wastewater are: COD 690.0 mgO 2 /L, pH 6.8, total suspended solids (TSS) 460.0 mg/L, total nitrogen (TN) 89.5 mg/L, total phosphorus (TP) 11.9 mg/L 50 . The WWTP B is located in north-eastern Poland. It purifies wastewater from 21.000 inhabitants. It processes approximately 5,000 m 3 daily. Theoretical capacity of WWTP B equals 6,600 m 3 /day. The main source of contamination affecting the drains is municipal and industrial (dairy, charcoal and briquette production, bio-fuels). Treatment efficiency meets the effluent standards required by Polish legislation for a plant of this size. Treatment processes used by WWTPs include mechanical purification as well as biological purification through the use of activated sludge in sequential batch reactors (SBR). Average parameters of raw wastewater are: COD 1,079 mgO 2 /L, pH 6.9, TSS 430.0 mg/L, TN 71.0 mg/L, and TP 11.8 mg/L 51 . Considered Milk Processing Plant (MPP) belongs to the largest Polish Dairy Cooperative, which is one of the twenty largest dairy processors in Europe 52 . It processes 54 million liters of milk per year. The MPP discharges dairy wastewater to the municipal WWTP after the pretreatment process. The average daily amount of dairy wastewater is 430 m 3 /day, which is about 13% of the total volume of wastewater flowing into the WWTP. In terms of BOD 5 and COD load dairy sewage has 7% share in the pollution load 53 . Wastewater samples were gathered through the use of glass samplers, placed into glass bottles and then transported to the laboratory. Obtained samples were filtered through a 0.45 µm pore membrane filter and fixed with concentrated HCl to pH=2. Samples were then stored in a freezer at -20 o C. pH and electrolytic conductivity (EC) in municipal and dairy wastewater were measured directly using probe of Hach HQd Meter and IntelliCAL Smartprobes type, Germany. Analyses of BOD 5 ; COD; orthophosphates; TP; ammonia nitrogen; nitrates; TN; TSS were carried out in accordance with APHA 54 . The procedure of benzotriazole microextraction with in situ derivatization For the simultaneous extraction and derivatization of BT, 4MBT, 5MBT, 5ClBT, UV326, and UV329 an aliquots of 5 mL of examined liquid sample was placed in 10-mL glass centrifuge test-tube. The extraction solvent (chlorobenzene, 80 µL) and the derivatization reagent (acetic anhydride, 120 µL) were added to such prepared samples and mixed. Then, tubes were immersed in an ultrasonic bath (Polsonic, Sonic-3, Poland). Extractions were performed at 42 kHz of ultrasound frequency and 230 W of power for the duration of 5 min at the room temperature. Emulsions were disrupted by centrifugation at 6000 rpm for 5 min in an MPW-250 Med. Instruments (Poland) laboratory centrifuge. The organic phase was settled at the bottom of the conical tube, which was removed using a 100 µL Hamilton syringe (USA) and transferred into chromatographic vial with a 150 µL insert. GC-MS conditions Analysis was performed with a HP 6890 gas chromatograph with a mass spectrometric detector MSD5973 and HP 7673 autosampler (Agilent Technologies, USA). This device was equipped with HP-5MS column (5% phenylmethylsiloxane) size 30m length x 0.25mm with 0.25µm film thickness and split/splitless injector. The injector worked in splitless mode, injection volume was 1 µL. Helium of purity 99.999% was used as carrier gas at flow rate 1 mL/min. The injector temperature was 250 o C. The oven temperature was programmed from 80 o C, increased at 10 o C/min to 180 o C and 20 o C/min to 280 o C. The total run time was 17.00 minutes, the retention times were as follows: 8.00 min (BT), 9.16 min (4MBT), 9.46 min (5MBT), 9.85 min and 9.91 min (5ClBT), 15.99 min (UV326), 16.46 min (UV329). The electron impact source temperature was 230 o C with electron energy of 70 eV. The quadrupole temperature was 150 o C, and the GC interface temperature was 280 o C. The MS detector worked in Selected Ion Monitoring (SIM) mode. The SIM chromatogram of the mili-Q water spiked with mixture of target compounds (100 µg/L each) is presented in Figure S1 (Supplementary Material). Registered EI-MS spectra of analytes are presented in Figure S2 (Supplementary Material). All signals were well separated. Single, good shape, and repeatable peaks for acetyl derivatives of BT, 4MBT, 5MBT, UV329 were obtained. UV326 did not undergo an acylation reaction due to a steric hindrance that prevented the derivatization reagent from accessing the OH group (see Figure S2, Supplementary Material). The chromatographic and mass spectrometric parameters together with some charasteristics and structures of target compounds are included in Table S7 (Supplementary Material). Calculation of mass loads Mass loads ( ML ) were calculated by multiplying concentrations of each target compound found in wastewater samples ( C , µg/L) the average daily flow rate ( Q , m 3 /day) of the tasted plant and the population served by the WWTP ( P ). ML values were normalized using the community equivalent (1000) according to Eq. (1) and they were expressed in mg/day/1000 inhabitants. The ML values of BTs flowing into WWTP A along with influents and the ML values of BTs introduced into the environment along with treated wastewater were determined. Quality assurance Apparatus (GC-MS) and procedural blanks were registered before analysis of samples or standards, and several times during analysis cycle to check no carry-over effect and purity of reagents and equipment used. Brand new test tubes and only glass materials were applied in experiments to avoid possible bacground contamination and losses of analytes by sorption on plastic. Concentrations of studied compounds in all influent and effluent samples they were calculated on the basis of the calibration curves registered in analyzed matrix. The determinations in the wastewater collected from the nitrification chamber and from SBR were performed based on the curves recorded for effluents. Determinations in wastewater collected from retention chamber (after mechanical tratment) were done on the basis of calibration on influents. Declarations Funding The research was supported by the Minister of Science and Higher Education (project No. WZ/WBiIŚ/8/2019 of the Technical University of Bialystok) and by the Polish National Centre of Science by grant 2019/03/X/ST10/01959. Author contributions Conceptualization: U.K., J.S.-S., J.P. Methodology: U.K. Investigation: U.K., J.S.-S., J.P. Data Curation: U.K. Writing - Original Draft: U.K., J.S.-S. Writing - Review & Editing U.K., J.S.-S. Funding acquisition U.K., J.S.-S., J.P. All authors reviewed and approved the manuscript. Competing interests The authors declare no competing interests. Additional information Correspondence and requests for materials should be addressed to U.K. References Żyłka, R., Dąbrowski, W. & Karolinczak, B. Modeling of electric energy consumption during dairy wastewater treatment plant operation. 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USAEME-GC-MS method validation parameters determined with water as sample matrix (SD – standard deviation; r 2 –coefficient of determination; CV - coefficient of variation; LoD – limit of detection; LoQ – limit of quantification; * x10 3 ) Compound Linearity r 2 Recovery (%) CV (%) LoD (ng/L) LoQ (ng/L) Slope (SD)* Intercept (SD)* 0.2 µg/L 2 µg/L BT 402 (6) 12 (14) 0.9983 112±1 106±5 6.4 1.2 4.0 4MBT 712 (11) 90 (36) 0.9960 108±8 112±2 6.5 0.7 2.3 5MBT 2 616 (42) -378 (118) 0.9900 98±8 95±2 8.8 0.2 0.5 5ClBT (peak1) 281 (4) 17 (38) 0.9971 96±4 102±2 7.7 1.7 5.7 5ClBT (peak2) 272 (6) 80 (23) 0.9918 116±3 87±7 9.8 1.8 5.9 5ClBT (∑) 599 (14) 59 (39) 0.9954 108±5 94±6 7.7 0.9 3.0 UV326 3786 (93) 641 (297) 0.9999 81±6 118±6 4.7 0.1 0.4 UV329 3608 (87) 1588 (752) 0.9900 106±7 121±6 6.6 0.1 0.5 Table 2. Comparison of the proposed method with other approaches based on different extraction techniques and gas chromatography detection ( LoD – limit of detection; *EI-MS unless otherwise stated; **ionic liquid stationary phase; ***triple quadrupole). Analytes Kind of matrix Sample volume (mL) Method Solvent volume (mL) LoDs (µg/L) Precission (%) Relative recovery* (%) Reference BT Airport run-off 500-1000 SPE-GC-MS* No data 0.1 No data No data 37 LMBTs River 2500 SPE-GC-MS 8 0.008-0.012 No data 62-70 35 LMBTs Wastewater 200 SPE-GC-MS** 25 No data <10.0 78-98 31 LMBTs Airport run-off No data SPE-GC-MS 61 0.0003-0.01 7.2-12 68-102 23 LMBTs Tap, groundwater, effluents 1000 SPE-GC-MS/MS*** 19 0.004-0.016 No data 70-122 22 LMBTs Municipal wastewater 1000 SPE-GC-MS/MS 19 <0.02 1.2-5.1 75-133 34 LMBTs Tap, surface, wastewater 1.6-8 SPME-GC-MS/MS 0 0.2-15 0.1-27.0 57-117 55 LMBTs River, municipal wastewater 500-1000 SPE-GCxGC-ToF-MS 25 0.048-0.112 <15.7 78-115 46 LMBTs River 200 SPE-GCxGC-ToF-MS 22 0.006-0.038 10.0-12.0 66-102 6 LMBTs Tap, river, municipal wastewater 10 DLLME-GC-MS 1.6 0.007-0.080 <8.0 92-112 33 LMBTs Municipal and dairy wastewater 5 USAME-GC-MS 0.08 0.006-0.035 <11.7 77-137 This work BUVs Municipal wastewater 1000 SPE-GC-MS/MS 19 0.0015-0.0056 No data 89-110 22 BUVs Municipal wastewater 1000 SPE-GC-MS/MS 19 <0.0163 0.5-3.8 75-133 34 BUVs Municipal and dairy wastewater 5 USAME-GC-MS 0.08 0.001-0.005 <9.3 107-124 This work Table 3. Concentration of benzotriazoles in analyzed municipal and dairy wastewater (MWWTP – municipal wastewater treatment plant; SC – sampling campaign; SBR - sequencing batch reactor; n.a.-not analyzed; *after mechanical treatment; ** after 190 minutes of aeration; ***from SBR, end of sedimentation). Origin of wastewater samples Concentration (µg/L) BT 4BT 5BT 5ClBT UV326 UV329 MWWTP A SC1 Influent 3.46 0.41 0.06 n.a. n.a. n.a. Denitrification chamber 3.21 0.44 0.7 n.a. n.a. n.a. Dephosphatation chamber 3.30 0.10 <LOD n.a. n.a. n.a. Nitrification chamber 2.28 0.09 <LOD n.a. n.a. n.a. Effluent 2.17 0.11 <LOD n.a. n.a. n.a. MWWTP A SC2 Influent 2.58 0.26 0.12 <LOD 0.01 0.01 Effluent 0.95 0.02 0.07 <LOD <LOD <LOD MWWTP A SC3 Influent 0.26 0.26 0.38 0.06 0.12 0.15 Effluent 0.06 0.06 0.07 0.01 0.03 0.03 MWWTP A SC4 Influent 0.21 0.08 0.05 0.05 0.17 0.14 Effluent 0.41 0.12 0.14 0.01 0.01 <LOD MWWTP A SC5 Influent 6.11 0.38 0.27 <LOD 0.28 0.21 Effluent 2.18 0.10 <LOD <LOD 0.08 0.07 MWWTP B Influent 0.61 5.31 0.07 n.a. n.a. n.a. Retention chamber* 1.15 0.46 0.64 n.a. n.a. n.a. SBR** 0.73 0.48 0.52 n.a. n.a. n.a. Effluent*** 0.62 0.49 0.49 n.a. n.a. n.a. MPP Influent <LOD 0.08 <LOD 0.09 0.01 0.01 After flotation <LOD <LOD <LOD <LOD <LOD <LOD Additional Declarations No competing interests reported. Supplementary Files Supplementarymaterialbis.docx Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Major revision 22 Mar, 2021 Reviews received at journal 09 Mar, 2021 Reviewers agreed at journal 03 Mar, 2021 Reviewers agreed at journal 03 Mar, 2021 Reviewers invited by journal 03 Mar, 2021 Editor assigned by journal 03 Mar, 2021 Editor invited by journal 25 Feb, 2021 Submission checks completed at journal 23 Feb, 2021 First submitted to journal 21 Feb, 2021 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-263795","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":13380171,"identity":"498bd378-6d1b-4202-a45d-e0c9939f89f4","order_by":0,"name":"Kotowska Urszula","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA0klEQVRIiWNgGAWjYDACHiCWYGCQg7DYgJidSC3GCC3MxGgBgsQGorUYnDn78INFxeH0DTdyDzB8KDvMYE5Qy9l2YwmJM4dzN9zIS2Ccce4wg2UzIS3n2RgkJNtu5264nWPAzNt2mMHgMGEtzD8k/91ONwBp+UuUlrNtbBKSDbcTwFoYidEieeYYm4XEsf+GM++/SzjYcy6dh6Bf+M6kMd+WqEmT5ztz9uCDH2XWcubsDQT0AAGzBJRxAIh5DAhrYGBg/IDMI0rLKBgFo2AUjCgAAMFcQsd8ikkGAAAAAElFTkSuQmCC","orcid":"","institution":"University of Białystok","correspondingAuthor":true,"prefix":"","firstName":"Kotowska","middleName":"","lastName":"Urszula","suffix":""},{"id":13380172,"identity":"6c80e7bf-439c-454a-a6dc-466afe48a150","order_by":1,"name":"Struk-Sokołowska Joanna","email":"","orcid":"","institution":"Bialystok University of Technology","correspondingAuthor":false,"prefix":"","firstName":"Struk-Sokołowska","middleName":"","lastName":"Joanna","suffix":""},{"id":13380174,"identity":"062f11a7-ea5d-4177-a54c-dbb00b36c42d","order_by":2,"name":"Piekutin Janina","email":"","orcid":"","institution":"Bialystok University of Technology","correspondingAuthor":false,"prefix":"","firstName":"Piekutin","middleName":"","lastName":"Janina","suffix":""}],"badges":[],"createdAt":"2021-02-21 11:59:06","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-263795/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-263795/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":6628738,"identity":"771030b3-e717-453c-bd4e-b2ad8f190b0e","added_by":"auto","created_at":"2021-03-05 00:11:55","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":218566,"visible":true,"origin":"","legend":"Influence of the type of solvent (A) and the volume of chlorobenzene (B) on the efficiency of benzotriazole extraction by the USAEME technique","description":"","filename":"fig1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-263795/v1/ed63fe26c43a56da42817d62.jpg"},{"id":6629211,"identity":"9da48ad9-4643-4a26-b886-325247da98e4","added_by":"auto","created_at":"2021-03-05 00:14:55","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":229501,"visible":true,"origin":"","legend":"Influence of the acetic anhydride volume (A), ionic strength (B), and extraction time (C) on the efficiency of benzotriazole extraction by the USAEME technique ","description":"","filename":"fig2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-263795/v1/8cc7a62a201433e62bcd3ac0.jpg"},{"id":6629727,"identity":"d2d99e82-d5e0-4477-bfb5-d278d1f9d17b","added_by":"auto","created_at":"2021-03-05 00:20:55","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":107571,"visible":true,"origin":"","legend":"Chromatograms recorded for the influent (A) and effluent (B) wastewater from WWTP A","description":"","filename":"fig3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-263795/v1/5617fc3e5e3558756c2f8abe.jpg"},{"id":6629217,"identity":"c07b451f-cf45-45a5-b9aa-150ea5825d69","added_by":"auto","created_at":"2021-03-05 00:14:55","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":183988,"visible":true,"origin":"","legend":"The range and mean mass loads of target compounds flowing with influents into WWTP (A) and introduced with effluents into the aquatic environment (B). ","description":"","filename":"fig4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-263795/v1/29d0b5da7eda47b39e1cb95f.jpg"},{"id":6629480,"identity":"c8169f22-ade9-4e2c-8d71-f22893e10189","added_by":"auto","created_at":"2021-03-05 00:17:55","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":12577,"visible":true,"origin":"","legend":"The range and average values of the removal efficiency of benzotriazoles in the WWTP A","description":"","filename":"fig5.png","url":"https://assets-eu.researchsquare.com/files/rs-263795/v1/4d36b60c93ff93602d038ad2.png"},{"id":13675391,"identity":"25b2626c-82a9-4d7f-b79d-84229f7567de","added_by":"auto","created_at":"2021-09-17 11:26:27","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":798059,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-263795/v1/3e1794b7-9314-4b9e-b688-8fccfa333663.pdf"},{"id":6629210,"identity":"b64b8d15-029c-47ec-87a1-81fd4c28901f","added_by":"auto","created_at":"2021-03-05 00:14:55","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":160463,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementarymaterialbis.docx","url":"https://assets-eu.researchsquare.com/files/rs-263795/v1/09af1fdd548d055279d2243c.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eSimultaneous Determination of Low Molecule Benzotriazoles and Benzotriazole UV Stabilizers in Wastewater by Ultrasound-Assisted Emulsification Microextraction Followed by GC-MS Detection\u003c/p\u003e","fulltext":[{"header":"Introduction","content":" \u003cp\u003eThe presence of organic micropollutants in various elements of the environment is a major problem, as these compounds can pose a significant threat to living organisms or entire ecosystems. Its presence is caused by rapid industrial and technological development\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e. Benzotriazole (BT) and its derivatives are high-production-volume chemicals, and reports on their toxicity require careful assessment of their distribution in the environment\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. Micropollutants from the BT group are formed as a combination of benzene and triazole particles. This structure is susceptible to a number of multiple reactions, resulting in a large number of derivatives. LMBTs are polar compounds and have good solubility in water\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. The pK\u003csub\u003ea\u003c/sub\u003e values of LMBTs are between 7.9 to 9.0. A solution of LMBT has a slightly acidic reaction. They tend to be non-ionic at neutral pH\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. Benzotriazole acts as an electron donor or precursor to radicals or carboanions. It is easily introduced into other chemical structures through a number of reactions such as condensation or addition\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e. The values of the octanol-water partition coefficient are 1.4 for BT and 1.7 for metylobenzotriazoles. Their properties also include considerable resistance to oxidation and biodegradation\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e. Therefore benzotriazoles are only partialy removed by activated sludge and other treatment processes such as chlorination and advanced oxidation\u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eBTs can form stable and durable complexes with metals, resulting in a protective layer on the metal surface. Anti-corrosion properties have particles containing in their structure a hydrogen atom in position 1 and compounds with methyl group, especially 5MBT and 4MBT. BTs can be used as solder, brass, steel, cast iron and aluminium protection agents and are used in heating systems\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. Phenyl group of benzotriazoles, especially in position 2, absorb UV light in the wavelength range 300 to 400 nm. There is a large group of compounds containing a benzotriazole moiety used to stabilise against UV radiation\u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e. BUVs protect against degradation and yellowing of products. They are used in the production of paints, films, plastics, coatings and are components of skin care products\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e,\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e. BT and its derivatives are a component of detergents, including dishwasher tablets and powder. Benzotriazoles are a component of antifreeze agents and de-icing agents. Antifreeze mixtures for various surfaces (roads, airports, car parks) are now widespread and widely used. As a result, the risk of BTs entering the environment from the above mentioned source is very high\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. BT derivatives are widely used in the pharmaceutical industry. They are also additives in petroleum products. One of the main objectives of using these compounds is to increase the efficiency and durability of products\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe biological activity of many BT derivatives and its durability in the environment is connected with observed negative impact on the aquatic and terrestrial organisms\u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e. These compounds are classified as hazardous to the environment and causing long-term harmful effects\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e. Benzotriazoles can be absorbed by inhaling the aerosol and by ingestion\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u003c/sup\u003e. Toxicological studies have shown that benzotriazoles have mutagenic and toxic effects on some microorganisms, including algae and also plants\u003csup\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e,\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e. BTs can inhibit the growth of bacteria and weaken their ability to degrade certain organic compounds, leading to impairment of the self-purification process when these compounds enter the river from a wastewater treatment plant\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. The BTs have been shown to be genotoxic and may disrupt hormonal management\u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e. BT at higher concentrations showed antagonistic interaction with the androgenic receptor and potential disruption of the thyroid hormone system and fatty acid metabolism\u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e. It has been proven that 1H-benzotriazole has carcinogenic properties for humans. According to Shi et al.\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e benzotriazoles are associated with the development of endometrial cancer. Toxicity studies have shown that direct contact with some widely used BUVs can cause inflammation and skin irritation. Gender-related hematological and histopathological changes in the liver, kidneys, spleen and thyroid glands were observed after long-term toxicity testing of 2-(3,5-di-tert-butyl-2-hydroxyphenyl) benzotriazole (UV-320) in rats. Similar properties were also shown for 2-(3,5-di-tertert-butyl-2-hydroxyphenyl) benzotriazole (UV-328)\u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e. Some BUVs were also found to have similar estrogenic effects to those shown by the natural sex hormone 17-β-estradiol\u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eBTs are fourt most aboundant aquatic contaminants, after ethylenediamine tetraacetic acid and its salts, nitrilotriacetic acid, and alkylbenzene sulfonates\u003csup\u003e\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e. Their annual consumption in the United States alone exceeds 9,000 tons, it can also be presumed that it is very high in all developed economies\u003csup\u003e\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e,\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e. Quantification of benzotriazoles and its derivatives in environmental samples is carried out mainly by chromatographic methods, although the literature describes the use of electrochemical and spectrophotometric methods for this purpose\u003csup\u003e\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e,\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e. High-performance or ultra-high-performance liquid chromatography (HPLC, UHPLC) is usually used to determine BTs in the environmental and in biological samples. Detection is carried out using UV spectrophotometr, diode array detector (DAD), or mass spectrometer (MS)\u003csup\u003e19,26\u0026minus;29\u003c/sup\u003e. The greatest sensitivity and selectivity of the determinations was achieved using UHPLC with tandem MS detector of triple quadrupole (QqQ MS/MS) or electrospray ionization (ESI MS/MS) configuration\u003csup\u003e\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u003c/sup\u003e. Determination of highly polar low mass compounds from the group of BT derivatives by GC requires the use of polar stationary phases or the conversion of compounds to less polar and more volatile derivatives, for example by acetylation or methylation\u003csup\u003e6,13,20,31\u0026minus;33\u003c/sup\u003e. Less polar BT derivatives such as BUVSs can be analyzed by GC on standard medium polar columns without a derivatization process\u003csup\u003e\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e,\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e\u003c/sup\u003e. MSs with electron ionization (EI) and a quadrupole (Q) or a time-of-flight (ToF) analyzers as well as tandem mass spectrometers (MS/MS) were used as GC detectors. Undoubtedly, the isolation and enrichment of samples is a key step in a correct analytical procedure for the determination of trace contaminants in a complex matrix. Wastewaters contain many chemical compounds, often with similar properties, and with a large variation in composition over time. A solid phase extraction (SPE) technique is usually used to extract benzotriazoles from aqueous samples\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e,\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e,\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e\u003c/sup\u003e. In recent years, microextraction techniques have become more and more important in environmental analysis, including benzotriazole analysis. Ahmad et al. described the use of bar adsorptive microextraction (BAME) to isolate BT and 5MBT from rain, tap, estuarine waters as well as wastewater\u003csup\u003e\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u003c/sup\u003e. Dispersive liquid-liquid microextraction (DLLME) was used for isolation of low molecule benzotriazoles in water samples\u003csup\u003e\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e\u003c/sup\u003e. Lu et al. proposed the use of air assisted liquid-liquid microextraction (AALLME) in the procedure for the determination of BT, 5MBT and 5ClBT in aqueous samples\u003csup\u003e\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe aim of presented work was the development of a simple methodology based on ultrasound assisted emulsification microextraction (USAEME) with \u003cem\u003ein-situ\u003c/em\u003e derivatization and GC-MS for simultaneous determination four LMBTs: BT, 4MBT, 5MBT, and 5ClBT as well as two BUVs: UV 326 and UV329 in wastewater. The USAEME technique described for the first time by Requeiro et al. is isolation technique based on the emulsification of a microliter volume of organic solvent in aquous sample by ultrasound radiation and separation of both phases by centrifugation\u003csup\u003e\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e\u003c/sup\u003e. The literature review shows that so far USAEME has not been used for determination of BTs in any matrix, and no liquid-liquid microextraction has ever been used in the determination of the BUVs in any samples. Wastewater samples taken from municipal and industrial WWTPs collected at various stages of the technological process have been analyzed. The effectiveness of the BTs removal processes in individual tested unit as well as its mass loads was also determined.\u003c/p\u003e "},{"header":"Results And Discussion","content":"\u003cp\u003e\u003cstrong\u003eOptimization of the extraction and derivatization procedure \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eVery few procedures for the determination of benzotriazoles by GC in combination with single quadrupole MS have been published\u003csup\u003e23,31,33,35,37\u003c/sup\u003e. Based on previous literature reports, an acetylation reaction was selected for the derivatization of BTs in this work, which was carried out simultaneously with the extraction process. A careful impact analysis has been carried out for the following process conditions: the type and volume of the extraction solvent, the volume of acetic anhydride (derivatization reagent), the addition of a buffer salt and the time of simultaneous extraction and derivatization. \u003cem\u003en\u003c/em\u003e-Hexadecane, 1-undecanol, chloroform, carbon tetrachloride, toluene and chlorobenzene were tested as potential extraction solvents. The characteristics of selected solvents are included in Table S1 (Supplementary Material). The responses obtained for each analyzed compound when different solvents were used for extraction are shown in Fig. 1A. The volume of each of the solvents used for the extraction was 100 \u0026micro;L. Optimization was performed for milli-Q water to which a mixture of analytes was introduced, with a concentration of 10 \u0026micro;g/L each. Other conditions of the process were as follows: 100 \u0026micro;L of acetic anhydride, five minutes extraction time. The same conditions were used in all optimization experiments unless otherwise stated.\u003c/p\u003e\n\u003cp\u003eChlorinated solvents with a density greater than that of water were selected for the tests (see Table S1, Supplementary Material), enabling easy removal of the organic layer after extraction by using test tubes with a conical bottom\u003csup\u003e36\u003c/sup\u003e. \u003cem\u003en\u003c/em\u003e-Hexadecane and 1-undecanol make it possible to separate from the aqueous solution after extraction by solidifying a floating solvent drop, due to the corresponding melting points, which are 18\u003csup\u003eo\u003c/sup\u003eC and 13\u003csup\u003eo\u003c/sup\u003eC, respectively\u003csup\u003e38\u003c/sup\u003e. Aromatic solvents were selected due to their structural similarity to analytes and the possibility of forming \u0026pi;-\u0026pi; interactions, which may positively affect the extraction efficiency\u003csup\u003e33\u003c/sup\u003e. As expected, the highest extraction efficiency was achieved with the use of chlorobenzene and toluene, while the area of the chromatographic peaks recorded when the extractant was chlorobenzene was 13 to 22% higher than in the case of toluene. It can also be seen that for chlorobenzene, the lowest standard deviations of the recorded peak areas were recorded. When making the selection, the toxicity of solvents was also taken into account, which was against the chlorobenzene. In contrast, the toxicity of chlorobenzene is lower than that of other organochlorine solvents used in microextraction techniques. The use of toluene as the extractant requires additional operations to separate it from the extracted matrix. Moving to other vessels for this purpose is associated with the risk of losing some of the solvent or recontaminating the sample. At the same time, all additional operations increase the exposure of the analyst and the environment to the contact with the solvent. Taking all the above into account, chlorobenzene was selected as the optimal solvent for the extraction.\u003c/p\u003e\n\u003cp\u003eOptimal solvent volume was selected on the basis of tests performed at 40, 60 and 80 \u0026micro;L. The results of the conducted experiments are presented in Fig. 1B. As expected, there was clearly an inverse relationship between the volume of the solvent and the area of the obtained analyte peaks. Therefore, it was found that the volume of 40 \u003cem\u003e\u0026micro;\u003c/em\u003eL is optimal for the conducted experiments. The solubility of chlorobenzene in water is approximately 500 mg/L, so the theoretical amount of solvent that can be recovered after extracting a 5 mL water sample is 37.5 \u0026micro;L. After extraction, it was possible to collect about 25 \u0026micro;L of chlorobenzene, which made it possible to carry out several replications of the analysis using the autosampler of the GC-MS device. In order to make sure that the determined optimal volume could be used during the wastewater analysis, additional experiments were carried out using influents as well as the wastewater from different treatment stages. For influents, it was found necessary to use a solvent volume of 80 \u0026micro;L to obtain 15-20 \u0026micro;L of extract that could be analyzed by GC-MS. It is related to the presence of a rich matrix in wastewater, including macromolecular compounds (proteins, fats and carbohydrates), i.e. substances with emulsifying properties, increasing the solubility of chlorobenzene\u003csup\u003e39\u003c/sup\u003e. Therefore, it was decided to use a volume of solvent equal to 80 \u0026micro;L in all subsequent experiments. However, when the developed method will be used for samples of less polluted water, including surface water, groundwater, and purified sewage, it is possible to use a chlorobenzene volume of 40 \u0026micro;L.\u003c/p\u003e\n\u003cp\u003eThe optimization results for acetic anhydride volume, ionic strength and extraction time are shown in Fig. 2. The effect of acetic anhydride volume on the extraction efficiency was investigated in the range from 60 to 250 \u0026micro;L and 125 \u0026micro;L was selected as optimal. It turned out to be sufficient also when the experiments were repeated with samples of raw sewage enriched with analytes at a concentration of 100 \u0026micro;g/L.\u003c/p\u003e\n\u003cp\u003eMany studies have been carried out and described in the literature on the selection of the appropriate salt or buffer solution for liquid-liquid microextraction\u003csup\u003e36,40\u003c/sup\u003e. As a result, it was found that the optimal choice in this case are phosphoric (V) acid salts with buffering properties. In microextraction methods, especially in USAEME, the use of sodium bicarbonate is disadvantageous because the formation of CO\u003csub\u003e2\u003c/sub\u003e bubbles makes it difficult to separate the extract from the aqueous matrix\u003csup\u003e41\u003c/sup\u003e. However, the influence of the ionic strength on the process of benzotriazole microextraction is unclear, as the available literature gives completely opposite findings\u003csup\u003e26,33\u003c/sup\u003e. In this study, the effect of salt addition ranging from 0 to 10% was investigated. The obtained results do not show an unequivocal relationship between the obtained analyte peak areas and salt concentration. Similar results were obtained for concentrations of 0, 2.5 and 5%. In the case of concentrations of 7.5 and 10%, higher peak areas were obtained for BT and 4MBT, and lower for 5MBT. In order to definitively settle this issue, the research was repeated for 0 and 10% concentrations with the use of influent wastewater with addition of benzotriazoles. Studies have shown that in the case of a very complex matrix, which is untreated wastewater, the addition of buffering salt causes precipitation during extraction, which makes it difficult to take the appropriate volume of extract. Therefore, in further works, no salt was added to the extracted matrix. A similar solution was selected as optimal also when using the DLLME technique\u003csup\u003e33\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eThe relationship between the time of simultaneous extraction and derivatization, and the extraction efficiency was studied in the range of three to 12 minutes. Extending the simultaneous extraction and derivatization time from 3 to 5 minutes results in an increase in surface areas by about 10%. The surface areas obtained after 12 minutes of the process, for all tested compounds, were about 30% lower than those obtained after 5 minutes. The decrease in analyte surface areas with the extension of sonication time indicates that acetyl derivatives of benzotriazoles are likely to partially hydrolyze to free forms upon prolonged contact with the aqueous phase. This phenomenon has already been observed in the case of other polar compounds\u003csup\u003e38\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethod validation\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAnalytical parameters including linearity, precission, LoD, and limit of quantification (LoQ) as well as method recovery were investigated under established optimal conditions. Calibration curves were obtained by spiking the ultrapure water with seven concentration levels, between 0.05 and 10 \u0026micro;g/L and performing the extraction and GC-MS analysis. In the case of 5ClBT two chromatographic peaks were recorded. This situation is probably related to the formation of two isomeric acetyl derivatives of 5ClBT, substituted at the 1 and 3 positions of the triazole ring\u003csup\u003e42\u003c/sup\u003e. Calibration curves for this compound were plotted and validation parameters were determined based on peak 1, peak 2 and the sum of the peaks. The validation data are summarized in \u003cstrong\u003eTable 1\u003c/strong\u003e. Calibration curves were linear within the studied concentration ranges with coefficients of determination (r\u003csup\u003e2\u003c/sup\u003e) \u0026ge; 0.9900 for all target compounds.\u003c/p\u003e\n\u003cp\u003eThe LoD was established as the concentration giving a signal-to-noise ratio (S/N ratio) of 3 and it was measured in chromatograms registered for the solutions with lowest analytes concentration. The LoQ was calculated as the concentration corresponding to an S/N ratio of 10. LoDs and LoQs values for the tested benzotriazoles ranged from 0.1 to 1.8 ng/L and from 0.4 to 5.9 ng/L, respectively. The lowest detection and quantification limits were recorded for UV326, UV329 and 5MBT.\u003c/p\u003e\n\u003cp\u003eThe precision of the determinations was established on the basis of CV calculated for developed model (calibration curve). The CV for each point was calculated as the ratio of the root mean squared error to the mean of the concentration calculated on the basis of the model\u003csup\u003e43\u003c/sup\u003e. The CV given in \u003cstrong\u003eTable 1\u003c/strong\u003e was calculated as the average percent value of the variance coefficients determined for seven points of the calibration curves. For the individual compounds tested, mean CV values ranging from 4.7 to 9.8% were obtained. As expected, the measurements for higher concentrations are characterized by the highest precision. The mean CV value for all tested compounds at a concentration of 10 \u0026micro;g/L was 4.7%, while for the concentration of 0.05 \u0026micro;g/L it was almost 15%. Recoveries for each compound were determined at two concentration levels: 0.2 and 2 \u0026micro;g/L. They were calculated comparing nominal concentration with the value determined based on the calibration curve. The recovery values were between 81 and 116% for the lower concentration, and between 87 1nd 118% for the higher value.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMatrix effect\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMunicipal and industrial wastewater are water matrices with a high degree of pollution and properties strongly differing from those of pure water. A complicated matrix may affect the surface area of the obtained analytical signals as well as the location and course of the baseline. It is assumed that the influence of the matrix at the level of -20 to 20% is considered acceptable and determinations can be made on the basis of a calibration performed on a simplified matrix. With stronger disturbances, matrix-matched calibration must be used\u003csup\u003e44\u003c/sup\u003e. The tests of the resistance of the method showed that the discrepancies of the received signals exceed the determined range. The highest exceedances were recorded when the matrix was influents. Therefore, the developed method was validated with the use of six different real matrices (see Table S2 and Table S3, Supplementary Material). For all municipal wastewater matrix, good linearity was obtained, expressed as \u003cem\u003er\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e value above 0.99. The mean recovery deviation from the value of 100% was the highest for influent wastewater and was approximately 18%. In the case of the remaining matrices, it ranged from 8 to 13%, i.e. it did not differ significantly from the values determined for water. The CV values did not exceed 10%. It was probably influenced by the higher concentrations within the curve. The average sensitivity of determinations for the group of the target compounds, expressed by the LoD value, in the case of municipal wastewater as matrices, ranged from 6 to 14 ng/L. In the case of industrial wastewater as a sample matrix, the deviation of validation parameters from those registered for water is higher than in the case of municipal wastewater. In this case, average values of the difference in recovery from 100% equals 25% for influents and 12% for wastewater after flotation. Higher values of CV, and LoD were also recorded. It can be seen that the deterioration of the recovery and the reduction of sensitivity, is quite well correlated with the contamination of the matrix used, expressed by the BOD, COD, suspension, nitrogen and phosphorus concentrations (see Tables S4, S5, S6 Supplementary material).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComparison with other analytical procedures \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDue to its high polarity and limited volatility, liquid chromatography is the most commonly used in BTs analysis, usually combined with MS or MS/MS detection. The limited availability of this type of equipment as well as the high cost of determinations and large production of waste solvents are significant obstacles of LC-MS/MS technique. GC-MS systems, especially those with one quadrupole, are currently common equipment in laboratories conducting environmental determinations. At the same time, GC-MS analyzes are cost-friendly, easy to perform and environmentally friendly due to the small amount of waste generated. The development of derivatization in the matrix in recent years facilitated the use of GC in the analysis of compounds even with high polarity. Table 2 presents a comparison of the developed method with other solutions used in the determination of BTs. Due to the fact that in the literature from recent years there are comparisons of BTs determination methods, only procedures based on gas chromatography and various isolation techniques were taken into account\u003csup\u003e22,26,29\u003c/sup\u003e. Comparing the developed procedure with others described in the literature, it can be stated that the validation parameters determined by us are similar or better than in the case of other determinations performed with the GC-MS and GC-MS/MS techniques. The comparison of isolation techniques shows that SPE, DLLME and USAEME allow determinations with similar accuracy, precision and sensitivity, while the use of SPME is associated with the deterioration of the validation parameters of the procedure. It should be emphasized, however, that the procedures based on the use of SPE are multi-stage (conditioning of columns, sample application, elution, concentration of the eluate) and require a large volume of samples (even 2.5 L, on average 1L) and the use of large volumes of organic solvents (up to 61 mL per one repetition of the procedure)\u003csup\u003e23\u003c/sup\u003e. These facts justify the growing popularity of liquid-liquid microextraction techniques. The DLLME-GC-MS and USAEME-GC-MS procedures have similar analytical characteristics (with a slight advantage of the first technique), while the 20 times higher consumption of organic solvents in the DLLME technique (sum of the extraction and dispersion solvent volumes) should be considered as an advantage of USAEME. A significant improvement of the proposed method, compared to the DLLME-based procedure, is the simple, one-step recovery of the solvent after extraction, which is associated with a lower risk of sample contamination and analyte loss\u003csup\u003e33\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eWastewater analysis \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe developed USAEME-GC-MS procedure was used for the simultaneous determination of compounds from the LMBT and BUV groups in wastewater from two municipal wastewater treatment plants and in the outflow of MPP.\u003cstrong\u003e Fig. 3\u003c/strong\u003e show chromatograms recorded for the influent and effluent wastewater from WWTP A. \u003cstrong\u003eTable 3\u003c/strong\u003e summarizes the concentrations of the target LMBTs and BUVs in samples of municipal wastewater from WWTP A and WWTP B and in dairy wastewater from MPP. BT, 4MBT and 5MBT determinations were performed on six samples of municipal influents and six samples of effluents (five from WWTP A and one from WWTP B). 5ClBT, UV326, and UV329 determinations were carried out in four samples of each type from WWTP A. Average concentrations of LMBTs in influent wastewater, along with deviations, ranged from 0.055\u0026plusmn;0.007 \u0026micro;g/L for 5ClBT (N=2, two values below the LOD) to 2.205\u0026plusmn;2.335 \u0026micro;g/L for BT. Among the methyl derivatives of BT, the higher concentration of 1.117\u0026plusmn;2.058 \u0026micro;g/L was recorded for 4MBT and for 5MBT it was 0.158\u0026plusmn;0.136 \u0026micro;g/L. For BUVs, the mean concentrations in municipal influents were 0.190\u0026plusmn;0.082 \u0026micro;g/L and 0.167\u0026plusmn;0.038 \u0026micro;g/L for UV326 and UV329, respectively (N = 3, one value below LOD). In the treated wastewater, the average concentrations of BT (N=6), 4MBT (N=6), 5MBT (N=4) and 5ClBT (N=2) were 1.065\u0026plusmn;0.907 \u0026micro;g/L, 0.150\u0026plusmn;0.171 \u0026micro;g/L, 0.178\u0026plusmn;0.215 \u0026micro;g/L, and 0.010 \u0026micro;g/L, respectively. The mean concentrations of UV326 (N=3) and UV329 (N=2) were 0.040\u0026plusmn;0.036 \u0026micro;g/L and 0.050\u0026plusmn;0.028 \u0026micro;g/L, respectively. The LMBTs content in municipal influents determined in this study is similar to the values obtained during the research conducted in Spain by Dominguez et al.\u003csup\u003e31\u003c/sup\u003e. Other results that can be found in the literature indicate a higher content of these compounds, reaching 13 \u0026micro;g/L for BT and over 7 \u0026micro;g/L for other LMBTs\u003csup\u003e22,45,46\u003c/sup\u003e. The content of LMBTs in municipal effluents similar to that recorded by us was obtained by Liu et al. and Casado et al. for samples from Australia and Spain\u003csup\u003e22,33,34\u003c/sup\u003e. The remaining literature reports give higher concentrations of these compounds in effluents, reaching 10 \u0026micro;g/L\u003csup\u003e45\u003c/sup\u003e. The content of BUVs in municipal influents reported in the literature is over ten times higher than the values recorded by us\u003csup\u003e34\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003eFig. 4 shows the range and mean ML of target compounds flowing with influents into WWTP A and introduced with effluents from WWTP A into the aquatic environment. Fig. 5 shows the range and average values of the removal efficiency (RE) of individual compounds in the WWTP A. When no compound was detected in a specific matrix, the appropriate LOD value was inserted into the calculation of ML and RE. The ML values for each target compound was estimated according to Eq. (1). The average ML values calculated for influents ranged from approximately 8 mg/day/1000 inhabitants for 5ClBT to almost 600 mg/day/1000 inhabitants for BT. For the remaining compounds, these values were at the level of several dozen mg/day/1000. The lowest mass load introduced into the environment was recorded for 5ClBT and it was 2.2 mg/day/1000 inhabitants. 269 mg/day/1000 inhabitants was the ML for BT, which was the highest recorded value. The average ML value for the remaining compounds ranged from a few to several mg/day/1000 inhabitants.\u003c/p\u003e\n\u003cp\u003eEfficiency (RE, %) of the removal of LMBTs and BUVs during the treatment process depends on its tendency to be absorbed by activated sludge as well as its biodegradability and physiochemical properties (volatility, polarity, water solubility). RE is defined as negative or low when RE \u0026lt; 20%, moderate when the RE ranged between 20.1% and 70% and high when the RE exceeded 70.1% \u003csup\u003e47\u003c/sup\u003e. As shown in Fig. 5, the average RE value obtained for target compounds allows the removal efficiency of BT, 4MBT and 5MBT to be classified as moderate and 5ClBT, UV326, and UV329 as high. In the case of BT, 4MBT, 5MBT, in some sampling campaigns higher concentrations were observed in effluents than in influents, i.e. RE values below zero were obtained. \u0026ldquo;Negative removal\u0026rdquo; has been previously observed and it could be explained by the varying sorption of the target compounds in activated sludge and their subsequent desorption by successive portions of wastewater\u003csup\u003e48\u003c/sup\u003e. The reason may also be the fact that the influents and effluents were collected at the same time, while the treatment process in WWTP A takes about 48 hours, so the effluents come from a completely different portion of influents than taken on a given day\u003csup\u003e49\u003c/sup\u003e. On the basis of the obtained results it can be concluded that the removal of BTs by activated sludge processes is not sufficient and it is advisable to use additional technologies as the tertiary wastewater treatment.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eChemicals and solutions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAnalytes: BT, 4MBT, 5MBT on the purity of analytical standards were purchased from Supelco, Germany, and 5ClBT, UV326 and UV329 of the purity not less than 99% was obtained from Sigma-Aldrich, Germany. Most solvents: methanol, chloroform, carbon tetrachloride, acetone, chlorobenzene, toluene as well as anhydrous disodium hydrogen phosphate (V) (buffering salt) were purchased from POCH (Poland). Acetic anhydride (V) were provided by Chempur (Poland). Other solvents: 1-undecanol and \u003cem\u003en\u003c/em\u003e-hexadecane were obtained from Sigma-Aldrich, Germany. The standards were individually dissolved in methanol to obtain concentrations at 1 mg/mL. So prepared stock solutions were stored at \u0026ndash;20 \u003csup\u003eo\u003c/sup\u003eC not longer than two weeks. Working solutions were prepared by diluting the stock standard solution in methanol and stored at \u0026ndash;20 \u003csup\u003eo\u003c/sup\u003eC not longer than for two weeks. Deionized water was obtained using a purification system (Milli-Q RG, Millipore, USA) and was stored in glass bottles.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eWastewater samples\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAverage daily municipal wastewater samples were obtained from municipal wastewater treatment plants (WWTP) located in two cities in the north-east Poland. Treatment processes used by WWTPs include mechanical purification (such as grates, sieves, sand traps, settling tanks and grease separators) as well as biological purification through the use of activated sludge with no tertiary treatment. After the completion of treatment processes effluents are discharged into local rivers belonging to the catchment area of the Vistula River which is a part of the Baltic Sea drainage basin. The WWTP A is located in the city with a population of 300,000. Daily capacity of the WWTP A equals 100,000 m\u003csup\u003e3\u003c/sup\u003e/day. It\u0026rsquo;s average processing is approximately 70.000 m\u003csup\u003e3\u003c/sup\u003e/day. The work of the plant is based on active sludge technology (flow system) assuming the load of BOD\u003csub\u003e5\u003c/sub\u003e equal to 30.000 kg O\u003csub\u003e2\u003c/sub\u003e/day, suspension load of 55,000 kg/day, total Kjeldahl nitrogen 6,000 kg/day, and total phosphorus 850 kg/day. Treatment efficiency meets the effluent standards required by Polish legislation for a plant of this size. Average parameters of raw wastewater are: COD 690.0 mgO\u003csub\u003e2\u003c/sub\u003e/L, pH 6.8, total suspended solids (TSS) 460.0 mg/L, total nitrogen (TN) 89.5 mg/L, total phosphorus (TP) 11.9 mg/L\u003csup\u003e50\u003c/sup\u003e. The WWTP B is located in north-eastern Poland. It purifies wastewater from 21.000 inhabitants. It processes approximately 5,000 m\u003csup\u003e3 \u003c/sup\u003edaily. Theoretical capacity of WWTP B equals 6,600 m\u003csup\u003e3\u003c/sup\u003e/day. The main source of contamination affecting the drains is municipal and industrial (dairy, charcoal and briquette production, bio-fuels). Treatment efficiency meets the effluent standards required by Polish legislation for a plant of this size. Treatment processes used by WWTPs include mechanical purification as well as biological purification through the use of activated sludge in sequential batch reactors (SBR). Average parameters of raw wastewater are: COD 1,079 mgO\u003csub\u003e2\u003c/sub\u003e/L, pH 6.9, TSS 430.0 mg/L, TN 71.0 mg/L, and TP 11.8 mg/L\u003csup\u003e51\u003c/sup\u003e. Considered Milk Processing Plant (MPP) belongs to the largest Polish Dairy Cooperative, which is one of the twenty largest dairy processors in Europe\u003csup\u003e52\u003c/sup\u003e. It processes 54 million liters of milk per year. The MPP discharges dairy wastewater to the municipal WWTP after the pretreatment process. The average daily amount of dairy wastewater is 430 m\u003csup\u003e3\u003c/sup\u003e/day, which is about 13% of the total volume of wastewater flowing into the WWTP. In terms of BOD\u003csub\u003e5\u003c/sub\u003e and COD load dairy sewage has 7% share in the pollution load\u003csup\u003e53\u003c/sup\u003e. Wastewater samples were gathered through the use of glass samplers, placed into glass bottles and then transported to the laboratory. Obtained samples were filtered through a 0.45 \u0026micro;m pore membrane filter and fixed with concentrated HCl to pH=2. Samples were then stored in a freezer at -20 \u003csup\u003eo\u003c/sup\u003eC. pH and electrolytic conductivity (EC) in municipal and dairy wastewater were measured directly using probe of Hach HQd Meter and IntelliCAL Smartprobes type, Germany. Analyses of BOD\u003csub\u003e5\u003c/sub\u003e; COD; orthophosphates; TP; ammonia nitrogen; nitrates; TN; TSS were carried out in accordance with APHA\u003csup\u003e54\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe procedure of benzotriazole microextraction with in situ derivatization\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFor the simultaneous extraction and derivatization of BT, 4MBT, 5MBT, 5ClBT, UV326, and UV329 an aliquots of 5 mL of examined liquid sample was placed in 10-mL glass centrifuge test-tube. The extraction solvent (chlorobenzene, 80 \u0026micro;L) and the derivatization reagent (acetic anhydride, 120 \u0026micro;L) were added to such prepared samples and mixed. Then, tubes were immersed in an ultrasonic bath (Polsonic, Sonic-3, Poland). Extractions were performed at 42 kHz of ultrasound frequency and 230 W of power for the duration of 5 min at the room temperature. Emulsions were disrupted by centrifugation at 6000 rpm for 5 min in an MPW-250 Med. Instruments (Poland) laboratory centrifuge. The organic phase was settled at the bottom of the conical tube, which was removed using a 100 \u0026micro;L Hamilton syringe (USA) and transferred into chromatographic vial with a 150 \u0026micro;L insert.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eGC-MS conditions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAnalysis was performed with a HP 6890 gas chromatograph with a mass spectrometric detector MSD5973 and HP 7673 autosampler (Agilent Technologies, USA). This device was equipped with HP-5MS column (5% phenylmethylsiloxane) size 30m length x 0.25mm with 0.25\u0026micro;m film thickness and split/splitless injector. The injector worked in splitless mode, injection volume was 1 \u0026micro;L. Helium of purity 99.999% was used as carrier gas at flow rate 1 mL/min. The injector temperature was 250\u003csup\u003eo\u003c/sup\u003eC. The oven temperature was programmed from 80\u003csup\u003eo\u003c/sup\u003eC, increased at 10\u003csup\u003eo\u003c/sup\u003eC/min to 180\u003csup\u003eo\u003c/sup\u003eC and 20\u003csup\u003eo\u003c/sup\u003eC/min to 280\u003csup\u003eo\u003c/sup\u003eC. The total run time was 17.00 minutes, the retention times were as follows: 8.00 min (BT), 9.16 min (4MBT), 9.46 min (5MBT), 9.85 min and 9.91 min (5ClBT), 15.99 min (UV326), 16.46 min (UV329). The electron impact source temperature was 230\u003csup\u003eo\u003c/sup\u003eC with electron energy of 70 eV. The quadrupole temperature was 150\u003csup\u003eo\u003c/sup\u003eC, and the GC interface temperature was 280\u003csup\u003eo\u003c/sup\u003eC. The MS detector worked in Selected Ion Monitoring (SIM) mode. The SIM chromatogram of the mili-Q water spiked with mixture of target compounds (100 µg/L each) is presented in Figure S1 (Supplementary Material). Registered EI-MS spectra of analytes are presented in Figure S2 (Supplementary Material). All signals were well separated. Single, good shape, and repeatable peaks for acetyl derivatives of BT, 4MBT, 5MBT, UV329 were obtained. UV326 did not undergo an acylation reaction due to a steric hindrance that prevented the derivatization reagent from accessing the OH group (see Figure S2, Supplementary Material). The chromatographic and mass spectrometric parameters together with some charasteristics and structures of target compounds are included in Table S7 (Supplementary Material).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCalculation of mass loads \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMass loads (\u003cem\u003eML\u003c/em\u003e) were calculated by multiplying concentrations of each target compound found in wastewater samples (\u003cem\u003eC\u003c/em\u003e, \u0026micro;g/L) the average daily flow rate (\u003cem\u003eQ\u003c/em\u003e, m\u003csup\u003e3\u003c/sup\u003e/day) of the tasted plant and the population served by the WWTP (\u003cem\u003eP\u003c/em\u003e). \u003cem\u003eML\u003c/em\u003e values were normalized using the community equivalent (1000) according to Eq. (1) and they were expressed in mg/day/1000 inhabitants.\u003c/p\u003e\n\u003cp\u003e\u003cimg src=\"https://myfiles.space/user_files/58894_9946feeafa4c1df7/58894_custom_files/img1614844259.JPG\" alt=\"\" /\u003e\u003c/p\u003e\n\u003cp\u003eThe \u003cem\u003eML\u003c/em\u003e values of BTs flowing into WWTP A along with influents and the \u003cem\u003eML\u003c/em\u003e values of BTs introduced into the environment along with treated wastewater were determined.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eQuality assurance\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eApparatus (GC-MS) and procedural blanks were registered before analysis of samples or standards, and several times during analysis cycle to check no carry-over effect and purity of reagents and equipment used. Brand new test tubes and only glass materials were applied in experiments to avoid possible bacground contamination and losses of analytes by sorption on plastic. Concentrations of studied compounds in all influent and effluent samples they were calculated on the basis of the calibration curves registered in analyzed matrix. The determinations in the wastewater collected from the nitrification chamber and from SBR were performed based on the curves recorded for effluents. Determinations in wastewater collected from retention chamber (after mechanical tratment) were done on the basis of calibration on influents.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe research was supported by the Minister of Science and Higher Education (project No. WZ/WBiIŚ/8/2019 of the Technical University of Bialystok) and by the Polish National Centre of Science by grant 2019/03/X/ST10/01959.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eConceptualization: U.K., J.S.-S., J.P. Methodology: U.K. Investigation: U.K., J.S.-S., J.P. Data Curation: U.K. Writing - Original Draft: U.K., J.S.-S. Writing - Review \u0026amp; Editing U.K., J.S.-S. Funding acquisition U.K., J.S.-S., J.P. All authors reviewed and approved the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAdditional information\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCorrespondence and requests for materials should be addressed to U.K.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eŻyłka, R., Dąbrowski, W. \u0026amp; Karolinczak, B. Modeling of electric energy consumption during dairy wastewater treatment plant operation. \u003cem\u003eEnergies.\u003c/em\u003e \u003cb\u003e13\u003c/b\u003e, 3769 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAsimakopoulos, A. 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Eng.\u003c/em\u003e \u003cb\u003e8\u003c/b\u003e, 104405 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStruk-Sokołowska, J., Mielcarek, A., Wiater, J. \u0026amp; Rodziewicz, J. Impacts of dairy wastewater and pre-aeration on the performance of SBR. \u003cem\u003eDesalination Water Treat.\u003c/em\u003e \u003cb\u003e105\u003c/b\u003e, 41\u0026ndash;50 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStruk-Sokołowska, J. Changes of COD fractions share during municipal wastewater treatment with big dairy wastewater participation. \u003cem\u003eRocznik Ochrona Środowiska.\u003c/em\u003e \u003cb\u003e13\u003c/b\u003e, 2015\u0026ndash;2032 (2011).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStruk-Sokołowska, J., Rodziewicz, J. \u0026amp; Mielcarek, A. Effect of dairy wastewater on changes in COD fractions in technical-scale SBR type reactors. \u003cem\u003eWater Sci. Technol.\u003c/em\u003e \u003cb\u003e1\u003c/b\u003e, 156\u0026ndash;169 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRice, E. W., Baird, R. B., Eaton, A. D. \u0026amp; Clesceri, L. S. Standard methods for the examination of water and wastewater. 23 nd Edition. (Ame. Pub. Hea. Ass. (APHA), Ame. Wat. Wor. Ass. (AWWA), Wat. Envir. Fed. (WEF) 2017).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNaccarato, A., Gionfriddo, E., Sindona, G. \u0026amp; Tagarelli, A. Simultaneous determination of benzothiazoles, benzotriazoles and benzosulfonamides by solid phase microextraction-gas chromatography-triple quadrupole mass spectrometry in environmental aqueous matrices and human urine. \u003cem\u003eJ. Chromatogr. A.\u003c/em\u003e \u003cb\u003e18\u003c/b\u003e, 164\u0026ndash;173 (2014).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003eTable 1.\u003c/strong\u003e USAEME-GC-MS method validation parameters determined with water as sample matrix (SD \u0026ndash; standard deviation; r\u003csup\u003e2\u003c/sup\u003e \u0026ndash;coefficient of determination; CV - coefficient of variation; LoD \u0026ndash; limit of detection; LoQ \u0026ndash; limit of quantification; * x10\u003csup\u003e3\u003c/sup\u003e)\u003c/p\u003e\n\u003ctable border=\"1\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"2\" width=\"92\"\u003e\n\u003cp\u003e\u003cstrong\u003eCompound\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd colspan=\"2\" width=\"198\"\u003e\n\u003cp\u003e\u003cstrong\u003eLinearity\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" width=\"57\"\u003e\n\u003cp\u003e\u003cstrong\u003er\u003csup\u003e2\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd colspan=\"2\" width=\"123\"\u003e\n\u003cp\u003e\u003cstrong\u003eRecovery (%)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" width=\"46\"\u003e\n\u003cp\u003e\u003cstrong\u003eCV\u003cbr /\u003e (%)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" width=\"50\"\u003e\n\u003cp\u003e\u003cstrong\u003eLoD (ng/L)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd rowspan=\"2\" width=\"50\"\u003e\n\u003cp\u003e\u003cstrong\u003eLoQ (ng/L)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"94\"\u003e\n\u003cp\u003e\u003cstrong\u003eSlope (SD)*\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"104\"\u003e\n\u003cp\u003e\u003cstrong\u003eIntercept (SD)*\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e\u003cstrong\u003e0.2 \u0026micro;g/L\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u003cstrong\u003e2 \u0026micro;g/L\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"92\"\u003e\n\u003cp\u003eBT\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"94\"\u003e\n\u003cp\u003e402 (6)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"104\"\u003e\n\u003cp\u003e12 (14)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e0.9983\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e112\u0026plusmn;1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e106\u0026plusmn;5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"46\"\u003e\n\u003cp\u003e6.4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"50\"\u003e\n\u003cp\u003e1.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"50\"\u003e\n\u003cp\u003e4.0\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"92\"\u003e\n\u003cp\u003e4MBT\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"94\"\u003e\n\u003cp\u003e712 (11)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"104\"\u003e\n\u003cp\u003e90 (36)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e0.9960\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e108\u0026plusmn;8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e112\u0026plusmn;2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"46\"\u003e\n\u003cp\u003e6.5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"50\"\u003e\n\u003cp\u003e0.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"50\"\u003e\n\u003cp\u003e2.3\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"92\"\u003e\n\u003cp\u003e5MBT\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"94\"\u003e\n\u003cp\u003e2\u0026nbsp;616\u0026nbsp;(42)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"104\"\u003e\n\u003cp\u003e-378 (118)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e0.9900\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e98\u0026plusmn;8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e95\u0026plusmn;2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"46\"\u003e\n\u003cp\u003e8.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"50\"\u003e\n\u003cp\u003e0.2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"50\"\u003e\n\u003cp\u003e0.5\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"92\"\u003e\n\u003cp\u003e5ClBT (peak1)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"94\"\u003e\n\u003cp\u003e281 (4)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"104\"\u003e\n\u003cp\u003e17 (38)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e0.9971\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e96\u0026plusmn;4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e102\u0026plusmn;2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"46\"\u003e\n\u003cp\u003e7.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"50\"\u003e\n\u003cp\u003e1.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"50\"\u003e\n\u003cp\u003e5.7\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"92\"\u003e\n\u003cp\u003e5ClBT (peak2)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"94\"\u003e\n\u003cp\u003e272 (6)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"104\"\u003e\n\u003cp\u003e80 (23)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e0.9918\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e116\u0026plusmn;3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e87\u0026plusmn;7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"46\"\u003e\n\u003cp\u003e9.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"50\"\u003e\n\u003cp\u003e1.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"50\"\u003e\n\u003cp\u003e5.9\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"92\"\u003e\n\u003cp\u003e5ClBT (\u0026sum;)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"94\"\u003e\n\u003cp\u003e599 (14)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"104\"\u003e\n\u003cp\u003e59 (39)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e0.9954\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e108\u0026plusmn;5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e94\u0026plusmn;6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"46\"\u003e\n\u003cp\u003e7.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"50\"\u003e\n\u003cp\u003e0.9\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"50\"\u003e\n\u003cp\u003e3.0\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"92\"\u003e\n\u003cp\u003eUV326\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"94\"\u003e\n\u003cp\u003e3786 (93)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"104\"\u003e\n\u003cp\u003e641 (297)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e0.9999\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e81\u0026plusmn;6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e118\u0026plusmn;6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"46\"\u003e\n\u003cp\u003e4.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"50\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"50\"\u003e\n\u003cp\u003e0.4\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"92\"\u003e\n\u003cp\u003eUV329\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"94\"\u003e\n\u003cp\u003e3608 (87)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"104\"\u003e\n\u003cp\u003e1588 (752)\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e0.9900\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e106\u0026plusmn;7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e121\u0026plusmn;6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"46\"\u003e\n\u003cp\u003e6.6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"50\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"50\"\u003e\n\u003cp\u003e0.5\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cbr /\u003eTable 2.\u003c/strong\u003e Comparison of the proposed method with other approaches based on different extraction techniques and gas chromatography detection\u003cstrong\u003e (\u003c/strong\u003e\u003cem\u003eLoD\u003c/em\u003e \u0026ndash; limit of detection; *EI-MS unless otherwise stated; **ionic liquid stationary phase; ***triple quadrupole).\u003c/p\u003e\n\u003ctable border=\"1\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd width=\"54\"\u003e\n\u003cp\u003e\u003cstrong\u003eAnalytes\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003e\u003cstrong\u003eKind of matrix\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u003cstrong\u003eSample volume (mL)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"95\"\u003e\n\u003cp\u003e\u003cstrong\u003eMethod\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u003cstrong\u003eSolvent volume (mL) \u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"76\"\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eLoDs\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e \u003cbr /\u003e (\u0026micro;g/L)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u003cstrong\u003ePrecission (%)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e\u003cstrong\u003eRelative \u003c/strong\u003e\u003cstrong\u003erecovery* (%)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u003cstrong\u003eReference\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"54\"\u003e\n\u003cp\u003eBT\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003eAirport run-off\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e500-1000\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"95\"\u003e\n\u003cp\u003eSPE-GC-MS*\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003eNo data\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"76\"\u003e\n\u003cp\u003e0.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003eNo data\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003eNo data\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u003csup\u003e37\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"54\"\u003e\n\u003cp\u003eLMBTs\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003eRiver\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e2500\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"95\"\u003e\n\u003cp\u003eSPE-GC-MS\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"76\"\u003e\n\u003cp\u003e0.008-0.012\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003eNo data\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e62-70\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u003csup\u003e35\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"54\"\u003e\n\u003cp\u003eLMBTs\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003eWastewater\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e200\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"95\"\u003e\n\u003cp\u003eSPE-GC-MS**\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e25\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"76\"\u003e\n\u003cp\u003eNo data\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u0026lt;10.0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e78-98\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u003csup\u003e31\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"54\"\u003e\n\u003cp\u003eLMBTs\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003eAirport run-off\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003eNo data\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"95\"\u003e\n\u003cp\u003eSPE-GC-MS\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e61\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"76\"\u003e\n\u003cp\u003e0.0003-0.01\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e7.2-12\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e68-102\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u003csup\u003e23\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"54\"\u003e\n\u003cp\u003eLMBTs\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003eTap, groundwater, effluents\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e1000\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"95\"\u003e\n\u003cp\u003eSPE-GC-MS/MS***\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e19\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"76\"\u003e\n\u003cp\u003e0.004-0.016\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003eNo data\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e70-122\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u003csup\u003e22\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"54\"\u003e\n\u003cp\u003eLMBTs\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003eMunicipal wastewater\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e1000\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"95\"\u003e\n\u003cp\u003eSPE-GC-MS/MS\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e19\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"76\"\u003e\n\u003cp\u003e\u0026lt;0.02\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e1.2-5.1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e75-133\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u003csup\u003e34\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"54\"\u003e\n\u003cp\u003eLMBTs\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003eTap, surface, wastewater\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e1.6-8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"95\"\u003e\n\u003cp\u003eSPME-GC-MS/MS\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"76\"\u003e\n\u003cp\u003e0.2-15\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e0.1-27.0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e57-117\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u003csup\u003e55\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"54\"\u003e\n\u003cp\u003eLMBTs\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003eRiver, municipal wastewater\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e500-1000\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"95\"\u003e\n\u003cp\u003eSPE-GCxGC-ToF-MS\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e25\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"76\"\u003e\n\u003cp\u003e0.048-0.112\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u0026lt;15.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e78-115\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u003csup\u003e46\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"54\"\u003e\n\u003cp\u003eLMBTs\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003eRiver\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e200\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"95\"\u003e\n\u003cp\u003eSPE-GCxGC-ToF-MS\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e22\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"76\"\u003e\n\u003cp\u003e0.006-0.038\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e10.0-12.0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e66-102\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u003csup\u003e6\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"54\"\u003e\n\u003cp\u003eLMBTs\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003eTap, river, municipal wastewater\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e10\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"95\"\u003e\n\u003cp\u003eDLLME-GC-MS\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e1.6\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"76\"\u003e\n\u003cp\u003e0.007-0.080\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u0026lt;8.0\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e92-112\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u003csup\u003e33\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"54\"\u003e\n\u003cp\u003eLMBTs\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003eMunicipal and dairy wastewater\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"95\"\u003e\n\u003cp\u003eUSAME-GC-MS\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e0.08\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"76\"\u003e\n\u003cp\u003e0.006-0.035\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u0026lt;11.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e77-137\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003eThis work\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"54\"\u003e\n\u003cp\u003eBUVs\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003eMunicipal wastewater\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e1000\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"95\"\u003e\n\u003cp\u003eSPE-GC-MS/MS\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e19\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"76\"\u003e\n\u003cp\u003e0.0015-0.0056\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003eNo data\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e89-110\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u003csup\u003e22\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"54\"\u003e\n\u003cp\u003eBUVs\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003eMunicipal wastewater\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e1000\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"95\"\u003e\n\u003cp\u003eSPE-GC-MS/MS\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e19\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"76\"\u003e\n\u003cp\u003e\u0026lt;0.0163\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e0.5-3.8\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e75-133\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u003csup\u003e34\u003c/sup\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"54\"\u003e\n\u003cp\u003eBUVs\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"113\"\u003e\n\u003cp\u003eMunicipal and dairy wastewater\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"95\"\u003e\n\u003cp\u003eUSAME-GC-MS\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e0.08\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"76\"\u003e\n\u003cp\u003e0.001-0.005\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003e\u0026lt;9.3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"66\"\u003e\n\u003cp\u003e107-124\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"57\"\u003e\n\u003cp\u003eThis work\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cbr /\u003eTable 3.\u003c/strong\u003e Concentration of benzotriazoles in analyzed municipal and dairy wastewater (MWWTP \u0026ndash; municipal wastewater treatment plant; SC \u0026ndash; sampling campaign; SBR - sequencing batch reactor; n.a.-not analyzed; *after mechanical treatment; ** after 190 minutes of aeration; ***from SBR, end of sedimentation).\u003c/p\u003e\n\u003ctable border=\"1\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd colspan=\"2\" rowspan=\"2\" width=\"215\"\u003e\n\u003cp\u003e\u003cstrong\u003eOrigin of wastewater samples \u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd colspan=\"6\" width=\"405\"\u003e\n\u003cp\u003e\u003cstrong\u003eConcentration (\u0026micro;g/L)\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"68\"\u003e\n\u003cp\u003e\u003cstrong\u003eBT\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"72\"\u003e\n\u003cp\u003e\u003cstrong\u003e4BT\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e\u003cstrong\u003e5BT\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"69\"\u003e\n\u003cp\u003e\u003cstrong\u003e5ClBT\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003e\u003cstrong\u003eUV326\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003e\u003cstrong\u003eUV329\u003c/strong\u003e\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"5\" width=\"86\"\u003e\n\u003cp\u003eMWWTP A\u003c/p\u003e\n\u003cp\u003eSC1\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"129\"\u003e\n\u003cp\u003eInfluent\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"68\"\u003e\n\u003cp\u003e3.46\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"72\"\u003e\n\u003cp\u003e0.41\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e0.06\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"69\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"129\"\u003e\n\u003cp\u003eDenitrification chamber\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"68\"\u003e\n\u003cp\u003e3.21\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"72\"\u003e\n\u003cp\u003e0.44\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e0.7\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"69\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"129\"\u003e\n\u003cp\u003eDephosphatation chamber\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"68\"\u003e\n\u003cp\u003e3.30\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"72\"\u003e\n\u003cp\u003e0.10\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e\u0026lt;LOD\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"69\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"129\"\u003e\n\u003cp\u003eNitrification chamber\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"68\"\u003e\n\u003cp\u003e2.28\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"72\"\u003e\n\u003cp\u003e0.09\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e\u0026lt;LOD\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"69\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"129\"\u003e\n\u003cp\u003eEffluent\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"68\"\u003e\n\u003cp\u003e2.17\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"72\"\u003e\n\u003cp\u003e0.11\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e\u0026lt;LOD\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"69\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"2\" width=\"86\"\u003e\n\u003cp\u003eMWWTP A\u003c/p\u003e\n\u003cp\u003eSC2\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"129\"\u003e\n\u003cp\u003eInfluent\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"68\"\u003e\n\u003cp\u003e2.58\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"72\"\u003e\n\u003cp\u003e0.26\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e0.12\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"69\"\u003e\n\u003cp\u003e\u0026lt;LOD\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003e0.01\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003e0.01\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"129\"\u003e\n\u003cp\u003eEffluent\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"68\"\u003e\n\u003cp\u003e0.95\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"72\"\u003e\n\u003cp\u003e0.02\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e0.07\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"69\"\u003e\n\u003cp\u003e\u0026lt;LOD\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003e\u0026lt;LOD\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003e\u0026lt;LOD\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"2\" width=\"86\"\u003e\n\u003cp\u003eMWWTP A\u003c/p\u003e\n\u003cp\u003eSC3\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"129\"\u003e\n\u003cp\u003eInfluent\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"68\"\u003e\n\u003cp\u003e0.26\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"72\"\u003e\n\u003cp\u003e0.26\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e0.38\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"69\"\u003e\n\u003cp\u003e0.06\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003e0.12\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003e0.15\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"129\"\u003e\n\u003cp\u003eEffluent\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"68\"\u003e\n\u003cp\u003e0.06\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"72\"\u003e\n\u003cp\u003e0.06\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e0.07\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"69\"\u003e\n\u003cp\u003e0.01\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003e0.03\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003e0.03\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"2\" width=\"86\"\u003e\n\u003cp\u003eMWWTP A\u003c/p\u003e\n\u003cp\u003eSC4\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"129\"\u003e\n\u003cp\u003eInfluent\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"68\"\u003e\n\u003cp\u003e0.21\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"72\"\u003e\n\u003cp\u003e0.08\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e0.05\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"69\"\u003e\n\u003cp\u003e0.05\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003e0.17\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003e0.14\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"129\"\u003e\n\u003cp\u003eEffluent\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"68\"\u003e\n\u003cp\u003e0.41\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"72\"\u003e\n\u003cp\u003e0.12\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e0.14\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"69\"\u003e\n\u003cp\u003e0.01\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003e0.01\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003e\u0026lt;LOD\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"2\" width=\"86\"\u003e\n\u003cp\u003eMWWTP A\u003c/p\u003e\n\u003cp\u003eSC5\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"129\"\u003e\n\u003cp\u003eInfluent\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"68\"\u003e\n\u003cp\u003e6.11\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"72\"\u003e\n\u003cp\u003e0.38\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e0.27\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"69\"\u003e\n\u003cp\u003e\u0026lt;LOD\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003e0.28\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003e0.21\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"129\"\u003e\n\u003cp\u003eEffluent\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"68\"\u003e\n\u003cp\u003e2.18\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"72\"\u003e\n\u003cp\u003e0.10\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e\u0026lt;LOD\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"69\"\u003e\n\u003cp\u003e\u0026lt;LOD\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003e0.08\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003e0.07\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"4\" width=\"86\"\u003e\n\u003cp\u003eMWWTP B\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"129\"\u003e\n\u003cp\u003eInfluent\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"68\"\u003e\n\u003cp\u003e0.61\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"72\"\u003e\n\u003cp\u003e5.31\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e0.07\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"69\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"129\"\u003e\n\u003cp\u003eRetention chamber*\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"68\"\u003e\n\u003cp\u003e1.15\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"72\"\u003e\n\u003cp\u003e0.46\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e0.64\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"69\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"129\"\u003e\n\u003cp\u003eSBR**\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"68\"\u003e\n\u003cp\u003e0.73\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"72\"\u003e\n\u003cp\u003e0.48\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e0.52\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"69\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd width=\"129\"\u003e\n\u003cp\u003eEffluent***\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"68\"\u003e\n\u003cp\u003e0.62\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"72\"\u003e\n\u003cp\u003e0.49\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"67\"\u003e\n\u003cp\u003e0.49\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"69\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"65\"\u003e\n\u003cp\u003en.a.\u003c/p\u003e\n\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd rowspan=\"2\" width=\"86\"\u003e\n\u003cp\u003eMPP\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"129\"\u003e\n\u003cp\u003eInfluent\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"68\"\u003e\n\u003cp\u003e\u0026lt;LOD\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd width=\"72\"\u003e\n\u003cp\u003e0.08\u003c/p\u003e\n\u003c/td\u003e\n\u003ctd 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Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Benzotriazoles, Municipal wastewater, Dairy wastewater, Ultrasound-assisted emulsification microextraction, Removal efficiency, Mass loads","lastPublishedDoi":"10.21203/rs.3.rs-263795/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-263795/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eA rapid, sensitive, economically and ecologically friendly method based on one-step ultrasound-assisted emulsification microextraction (USAEME) and \u003cem\u003ein situ\u003c/em\u003e derivatization followed by gas chromatography-mass spectrometry (GC-MS) for simultaneous determination of low molecular benzotriazoles (LMBTs) and benzotriazole-based ultraviolet filters (BUVs) was developed. The optimized method allow quantification of benzotriazole (BT), 4-methylbenzotriazole (4MBT), 5-methylbenzotriazole (5MBT); 5-chlorobenzotriazole (5ClBT), 2-(2′-hydroxy-3′-tert-butyl-5′-methylphenyl)-5-chlorobenzortriazole (UV326) and 2-(2′-hydroxy-5′-(1,1,3,3-tetramethylbutyl)phenyl)benzotriazole (UV329) in municipal and industrial (dairy) wastewater. The method was validated using real influent and effluent wastewater and samples at various stages of the purification process. Obtained relative recoveries were between 77 and 137%, limits of detection (LoDs) from 0.001 to 0.035 µg/L, the repeatability expressed by the coefficient of variation (CV) did not exceed 12%. The use of the method for the determination of the tested compounds in municipal and industrial wastewater showed their presence in most of the tested samples, in concentrations from LoD to 6.11 µg/L. The conducted studies of samples from municipal wastewater treatment plant (WWTP) located in north-eastern Poland showed that the effectiveness of benzotriazole removal by this plant is from 29 to 84%. The load of tested compounds released into the environment by this facility ranges from 2 to 269 mg/day/1000 inhabitants.\u003c/p\u003e","manuscriptTitle":"Simultaneous Determination of Low Molecule Benzotriazoles and Benzotriazole UV Stabilizers in Wastewater by Ultrasound-Assisted Emulsification Microextraction Followed by GC-MS Detection","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2021-03-05 00:11:53","doi":"10.21203/rs.3.rs-263795/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major revision","date":"2021-03-22T04:05:01+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2021-03-09T17:53:00+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"65b6c151-1937-47cf-a450-507b11cacae9","date":"2021-03-03T15:56:18+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"4612f6e4-8cb4-4f48-8969-0c0199c2c723","date":"2021-03-03T15:15:48+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2021-03-03T14:45:04+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2021-03-03T14:39:07+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2021-02-25T16:10:46+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2021-02-23T17:42:32+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2021-02-21T11:58:31+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"6a2e94d8-bd02-47b1-b30e-a80df2f81796","owner":[],"postedDate":"March 5th, 2021","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":2758402,"name":"Analytical Chemistry"},{"id":2758403,"name":"General Biochemistry"},{"id":2758404,"name":"Environmental Chemistry"}],"tags":[],"updatedAt":"2021-04-23T04:14:04+00:00","versionOfRecord":[],"versionCreatedAt":"2021-03-05 00:11:53","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-263795","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-263795","identity":"rs-263795","version":["v1"]},"buildId":"J0_U0BvcaRcwD8yVFaRlm","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}