Determination of 9 Pesticides Residues in Cowpeas by GPC-UPLC-MS/MS

The UPLC-MS/MS combined with gel permeation chromatography purification (GPC) was proposed to simultaneously measure 9 pesticides residues in cowpeas. The sample was extracted by acetonitrile,and purified by GPC. The eluate was separated by using Waters BEH C18 column as stationary phase,methanol and 1.0 mmol·L-1 ammonium acetate solution as mobile phase,and then detected by multiple reactions monitoring (MRM). Linearity range of the 9 pesticides was found between 0.01-0.50 mg·L-1 with correlation coefficients above 0.99. Tests for recovery were made by standard addition,giving recovery rates in the range of 72.2%-109% and RSD′s (n=5) in the range of 0.6%-8.9%.