Determination of 55 Residual Pesticides in Onion and Leek Samples Using GC-MS/MS

The analysis was done by GC/MS/MS in multiple reaction monitoring (MRM) mode. The optimization of MRM transition and collision energy for each compound was carried out by injecting pesticides at a concentration level of 10 mg/L. Every compound has 2 MRM transitions (primary for quantification, secondary for qualification). The correlation coefficients of target and internal standard substance were good from 0.001 mg/L to 0.1 mg/L(r2 >0.99）.The limits of detection (LODs) of all the pesticides studied were better than 0. 0001 mg/kg. The average recovery were between 70% and 120% and the relative standard deviation (%RSD, n = 6）were better than 11% at 0.001 mg/kg and 0.005 mg/kg with spiked samples.