Identification of organophosphorus pesticides residues (Diazinon, Isazofos, Terbufos, Chloropyrifos, Fenthion) from honey samples in East and West Azarbaijan Provinces using eutectic solvent based dispersive liquid-liquid microextraction followed by GC

Abstract

Goal: Because of using high amount of pesticides in agriculture and the risk caused by remains of these pesticides to humans health, this study wants to determine the amount of organophosphate pesticides in honey and present a way to dispersive liquid-liquid microextraction by using deep eutectic solvents and application of this method in extraction and preconcentration of final analytes from different types of honey and quantitive measurement of these compounds with Gas Chromatography. Materials and Methods: 10 samples of honey (7 of the honeys are the product of factories and 3 of the samples are non- packaged honeys) are collected in order to determine the remaining amount of Organophosphate toxin. In this method, a three-particle deep eutectic solvent produced by mixing Dichloroacetic acid, Phosphocholine chloride and Decanoic acid. and this solvent is used as extractor in microextraction stage. We mixed 1g honey sample and 2ml deionized water, and when the mixture get homogenized, a miscible solvent (Acetonitrile) added to mixture and the mixture stirred completely and centrifuged. Then the upper phase get extraction and mixed with the deep eutectic solvent and ejected into deionized water and sodium chloride with glass syringe. The final mixture centrifuged and the settled phase transferred to gas chromatograghy-mass spectrometry. to obtain the maximum efficiency, the suggested method get optimized with ''single parameter in a certain time method''. Finding: The optimal conditions achieved for extracting method of Dispersive liquid-liquid micro-extraction were included: sample volume of 2 mL-1, the volume of eutectic solvent of 60 μL, 2 mL-1 of dispersive acetonitrile solvent and 0.2 g Sodium Chloride. Amounts of the limits of detection and quantification, enrichment factors, extraction recoveries, relative standard deviations and linear range is 0.05-0.1 and 0.19-0.36ng/g, 82-98, 82-98%, RSD ≤ 10%, 0.36-1000 ng/g respectively. Also the results showed a sample of a packaged honey is infected by Malathion pesticide with the concentration of 29 ng/g. Results: By using dispersive liquid-liquid micro-extraction method, remaining amount of organophosphate toxins in honey samples were determined. All examined sample were free of any infection except one of which infected with organophosphate pest. The infection of the sample infected with organophosphate toxin was also within the determined standard range. As a result, this valuable food are not considered as a source of infection with this specific toxins in the studied areas. The obtained values showed that this method has a low limit of detection and low limit of quantification and high extraction recovery.