Simultaneous Analysis of Pesticide Multiresidues in Human Serum, Urine, Apiculture Samples, and Representative Crops Using Tandem Mass Spectrometry

Abstract

Pesticides are used for the effective control of pests, microorganisms, and weeds from crops and have contributed to food security. It is necessary to determine as many pesticides as possible in human, the environment, and agricultural products due to the intrinsic toxicity and ecotoxicity of pesticides. In this study, a tandem mass spectrometry coupled to a gas chromatography (GC-MS/MS) or liquid chromatography (LC-MS/MS) was utilized to determine approximately four hundreds of pesticides in biological samples (serum and urine), apiculture samples (bee, pollen, and honey), and representative crops (pepper, orange, brown rice, and soybean). The scheduled multiple reaction monitoring (MRM) of the tandem mass spectrometer was employed in all methodologies to achieve rapid and simultaneous analysis and to obtain optimal sensitivity and selectivity of target analytes. The preparation methods for serum and urine were selected by comparing with the three versions of Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) procedures. The optimized method was validated for 379 (serum) and 380 (urine) pesticides using LC-MS/MS. As a result, 94.5% (serum) and 95.8% (urine) of the total pesticides satisfied a limit of quantitation of 10 ng/mL. The established analytical method was applied to GC-MS/MS amenable pesticides (54 for serum and 55 for urine) and 53 analytes showed a limit of quantitation of 10 ng/mL. It was enough low sensitivity to determine pesticides in biological samples for forensic, clinical, and occupational exposure application. Apiculture samples, that is, bee (dead, healthy imago, and larva), pollen, and honey were treated by optimized QuEChERS methods. Among the pesticide multiresidues, three neonicotinoids (clothianidin, imidacloprid, and thiamethoxam), which are expected to be totally banned for outdoor use in the European Union (EU) by the end of 2018, were subjected to method validation. The limit of quantitation of each analyte was 1 ng/g and it was sufficiently low to determine pesticide residues below the levels of acute oral toxicity (LD50) of the bee. The field monitoring was conducted in two area near the apple orchard and pepper field in 2014. The analysis of the neonicotinoids and 391 multiresidue pesticides in apiculture samples were carried out. Based on residue levels, comprehensive honey bee exposure near farmland was able to be understood. Four representative crops were treated using miniaturized Multiclass Pesticide Multiresidue Method (No. 2) of the Korea Food Code, and the analytical method was evaluated for 384 pesticides using GC-MS/MS. As a result, 95.1-99.5% of the total pesticides satisfied the method limit of quantitation <10 ng/g in the crops, therefore the analytical method obtained the sufficient detection ability required by positive list system.