SP 01 - Determination of Multiresidue Pesticides in Soybean by Combining QuEChERS and CE-MS/MS
SP 01 - Determination of Multiresidue Pesticides in Soybean by Combining QuEChERS and CE-MS/MS
This application describes a sensitive and reliable capillary electrophoresis method for the determination of multiresidue pesticides in soybean. The residues of the seven different pesticides were extracted from soybean samples using the AOAC QuEChERS method without a cleanup step. The best separation of thiabendazole, aminocarb, imazalil, metoxuron, carbofuran, imazapyr, and metosulam was obtained in 100 mM formic acid (pH 2.4) as the background electrolyte (BGE), in less than eight minutes, using a polyvinyl alcohol coated capillary and detection by ESI-MS/MS. Samples were introduced hydrodynamically in 12 seconds at 100 mbar. During the electrophoretic run at 28 kV, a pressure of –20 mbar was applied to the inlet vial to compensate for the ESI suction effect [1]. The coefficient of determination (R2) for the matrix-matched calibration curves used for quantification in the range of 5 to 200 μg/L were greater than 0.996. Blank samples were fortified at three levels: 5, 40, and 200 μg/kg; recoveries ranged from 85 % to 120 %. Relative standard deviations were lower than 6.1 % in all cases. The limits of detection (LODs) based on the signal‑to-noise ratio (S/N) for all compounds was lower than 0.10 μg/kg, several times lower than the established Maximum Residue Limit (MRL) for soybean.
do Lago, C. L.; et al., Electrophoresis, issue 2014, pag. 35, 2412–2416, DOI: 10.1002/elps.201300651.