Electrochemical Method for the Assay of Organic Peroxides Directly in Acetonitrile

Lipid peroxidation is a major process that determines the quality of various oil samples during their use and storage, in which the primary products are hydroperoxides (HP’S). HP’S are very stable compounds at ambient conditions and are harmful to human health. Therefore, the eval-uation of the degree of oil oxidation is an excellent tool for ensuring food safety. Тhe peroxide value (PV) is the main parameter for quality control of oils. Herein, we propose an alternative electrochemical method to the most widely used classical iodometric titration for determining the PV. Our approach is based on the electrochemical quantification of hydroperoxides/peroxides in an organic solvent medium (acetonitrile and organic ammonium salt) using a composite electro-catalyst-glassy carbon electrode modified with 2D-nanomaterial graphitic carbon nitride doped with Co3O4. Calibration was made by standard addition method using benzoyl peroxide (BPO) as a model peroxide compound, dissolved in chloroform and added to fresh Rivana brand an-ti-cellulite oil used as a model oil sample. Calibration plots showed a linear response and very good reproducibility of the analytical result (R2˃0.99). Further, in term of accuracy, the method showed good results, since the BPO quantitative analysis was close to the theoretical response. In addition, the accuracy of the electrochemical method was compared with that of the standard iodometric titration method for determining the PV of vegetable fats (according to Bulgarian State Standard, BSS EN ISO 3960:2017). Finally, using the electrochemical method, the concentration of peroxides was determined in a real sample - an anti-cellulite oil of the trademark Rivana with an expired shelf life.