GC/MSD DETECTION OF THE METABOLIC RESIDUES OF METOLACHLOR IN TOMATO FRUIT

A gas chromatograph/mass selective detector method is presented for the analysis of the major metabolic residues of metolachlor by acid hydrolysis of tomato fruit. The two major hydrolysis products, CGA-37913 (2-[2-ethyl-6-methylphenyl]amino-1-propanol) and derivatised CGA-49751 (4-[2-ethyl-6-methylphenyl]-2-hydroxy-5-methyl-3-morpholinone) were monitored in the selective ion mode at m/z 162 and m/z 160, respectively. Recoveries from 87 to 96% were obtained for tomato fortified at 50 to 200-mu-g kg-1. The proposed method of analysis will allow for a detection limit of 11-mu-g kg-1 for CGA-37913 and 12-mu-g kg-1 for the derivatised CGA-49751.