MONITORING OF MULTI–CLASS PESTICIDES IN HONEY SAMPLES FROM MACEDONIA BY ULTRA HIGH PERFORMANCE LIQUID CHROMATOGRAPHY – TANDEM QUADRUPOLE MASS SPECTROMETRY

The possible presence of pesticide residues in honey has impelled the need for setting up monitoring programs to determine the proper assessment of human exposure to pesticides. This paper describes an effective multi-class method using a modified QuEChERS sample preparation for detection and quantification of 18 pesticides with Ultra-high-performance liquid chromatography (UHPLC) – tandem quadrupole mass spectrometry. The method was validated according to the requirements laid down in DG SANCO 12571/2013 document. Levels of detection and quantification were lower than the established MRLs, the obtained precision was better than 20 %, and the recovery values were between 74.4 and 104.1 %. Fifty honey samples within the national monitoring program were collected from August to November, 2014 and tested for presence of carbaryl, carbofuran, fenvalerate, cypermethrin, deltamethrin, permethrin, bifenthrin, amitraz, coumaphos, bromopropylate, dichlorvos, diazinone, malathion, parathion, dimethoate, omethoate, methomyl and thiametoxam. Trace levels of methomyl, diazinone, bromopropylate and fenvalerate were detected somewhat above the reporting level for these pesticides (10 μg/kg). This contamination indicates on existing of possible moderate cross-contamination during pollen and nectar collection by bees, and residues of substances used in beekeeping. Although traces of pesticides were found in 16 of the samples tested (32 %), the levels found did not pose increased toxicological risk for the population.