Determinação multirresíduo de agrotóxicos em abelha (Apis mellifera) empregando mini-QuEChERS e UHPLC-MS/MS

Abstract

Brazil has a favorable climate for extensive agricultural production, which is generally associated with the intensive use of pesticides. The harmful effect of pesticides on bee health is a topic of global concern. In the last decade, colony collapse disorder has affected bee colonies in many parts of the world and proposed reasons include reduced food availability, decreased diversity of flowers, parasites, modern beekeeping practices and continued exposure to pesticides. Therefore, the objective of this work was to develop and validate a method for multiresidue determination of pesticides in bees using ultra-high performance liquid chromatography coupled to serial mass spectrometry (UHPLC-MS/MS). For sample preparation, extraction solvents, partition salts and sorbents for cleaning the extracts were evaluated. Processing and extraction of 1 g of bee sample are performed simultaneously in the same tube with the aid of ultra-turrax using ultrapure water and acetonitrile containing 1% (v/v) of formic acid. Partitioning was achieved with anhydrous magnesium sulfate and sodium chloride, and the extract was cleaned with PSA and C18 sorbents. Pesticides were analyzed using a triple quadrupole UHPLC-MS/MS system. The proposed mini-QuEChERS method proved to be fast and effective for the determination of 176 pesticides in bees, with method quantification limits between 5 and 100 μg kg-1, in addition to excellent accuracy (recovery between 70 and 120%) and precision (RSD ≤ 18%). The proposed method was applied to 16 bee samples from different regions of the state of Rio Grande do Sul and nine pesticides were confirmed, and all samples showed at least one pesticide. The insecticide fipronil was present in 87% of the samples analyzed.