Cleanup Procedure for Determining of Pesticide Residues by Automated Gel Permeation Chromatography

Experiments on Rapid Methods for Pesticide Residue Analysis (Part 2)

Abstract

An automated GPC system was evaluated as a cleanup technique for determining pesticide residues. A sample was extracted with acetone and partitioned into dichloromethane to remove water. The extract was evaporated to dryness. The residue was cleaned up with the GPC system, using Bio-Beads SX-3 with a dichloromethane/cyclohexane (50:50, v/v) solvent system. The eluate of the GPC column was evaporated to dryness. The residue was dissolved in acetone and then injected into a gas chromatograph equipped with an alkali flame ionization detector. For cabbage, radish and soybean samples, supplemental Florisil was used in the cleanup procedure. Nineteen pesticide residues at 0.1-0.2ppm were determined in 16 crops to develop and test the method. Recoveries ranged from 75 to 110%. Detection limits by the method were 0.005-0.05ppm for 19 pesticides. This cleanup procedure using the automated GPC system is a fast and sensitive to quantify various pesticide residues simultaneously.