Determination of Multiclass Pesticides Residues in Corn by QuEChERS and Capillary Electrophoresis Tandem Mass Spectrometry
2019
Daniel, Daniela | do Lago, Claudimir Lucio
The development and validation of a capillary electrophoresis–tandem mass spectrometry method for the determination of nine pesticides residues in corn samples is presented. The residues of thiabendazole, aminocarb, imazalil, atrazine, metazachlor, metoxuron, carbofuran, metosulam, and imazapyr have been extracted from corn samples using QuEChERS based extraction procedure. The optimal separation of investigated pesticides was achieved in less than 6 min with 0.1 mol L⁻¹ formic acid (pH 2.4) as the background electrolyte using a poly(vinyl alcohol)-coated capillary. The coefficient of determination (r²), in the range of 5 to 200 μg L⁻¹, were greater than 0.995. Recoveries ranged from 70% to 110%. Relative standard deviations were lower than 7.8%. The limits of detection (LODs) ranged from 0.03 to 0.28 μg kg⁻¹, while the limits of quantitation (LOQs) ranged from 0.10 to 0.93 μg kg⁻¹, which are several times lower than the established maximum residue limits. These results suggest that the method attends the international legislation for all the analyzed pesticides in corn and that it has the potential to be successfully applied to other food matrices.
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