Multi-residue determination of 110 pesticides in agricultural products by GC/MS (SIM)

A method is described for the multi-residue determination of pesticides in agricultural products. Residues are extracted from samples with acetonitril e, and coextractives are removed by gel permeation chromatography, followed by a clean-up step through Bond Elut PSA and a silica-gel column, Analysis is performed by GC/MS (SIM). The method was evaluated in 4 or 5 laboratori es for 110 pesticides by fortifying rice, apple, orange, spinach, cabbage a nd potato at 0.2 mu g/g (Eor 5 pesticides, mu g/g) of each pesticide. The m ethod gave acceptable performance for analysis of 77 pesticides. The maximu m detection limit in 9 laboratories ranged from 0.0004 to 0.08 mu g/g, depe nding on the pesticide.