Synthesis of Azo-linked Porous Organic Polymers for Pipette Tip Solid-Phase Extraction of Sedative Residues from Animal Tissues Samples

Azo-linked porous organic polymers (APOPs) were synthesized by a simple azo reaction, with 2,2'-bis(trifluoromethyl)benzidine and 1,3,5-trihydroxybenzene as the monomers. The preparation process was mild, green and environmental-friendly, avoiding the use of high temperature, metal catalysis and harmful organic reagent. The obtained APOPs were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, powder X-ray diffraction and Brunauer-Emmett-Teller. With the prepared APOPs as adsorbent, a method of pipette tip solid-phase extraction-liquid chromatography tandem mass spectrometry detection (PTSPE-LC-MS/MS) was proposed for the analysis of target sedatives in animal tissues. Furthermore, the parameters for the extraction of five sedatives, including the amount of adsorbent, pH value, ion strength, elution solvent and volume, were investigated. Under the conditions optimized, the linear dynamic range was found from 0.1 µg kg − 1 to 10.0 µg kg − 1 , and the limits of detection were ranged from 0.02 µg kg − 1 to 0.1 µg kg − 1 . The method was assessed by the analysis of target sedatives in animal tissues, and the recoveries for the spiked pork samples and egg samples were 84–102% and 83–101%, respectively. The results show that the developed method of PTSPE-LC-MS/MS with APOPs as adsorbent is efficient for the analysis of trace sedatives in animal tissues.