RAPID ANALYSIS METHOD OF DITHIOCARBAMATE PESTICIDES IN AGRICULTURAL PRODUCTS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A rapid analysis method of dithiocarbamate pesticides in several agricultural commodities was developed. The compounds were extracted from the sample with an alkaline mixture of cysteine and EDTA. Ion-pair reagent was added to the extract and the pH was suitably adjusted, then part of the extract was poured into a Chem Elut(TM) cartridge and eluted with mixture of chloroform and hexane (3:1) contained 0.05 M methyl iodide. The eluate was injected into a high performance liquid chromatograph (HPLC). The methyl-esters derived from the dithiocarbamates were determined by HPLC with a UV detector. The chromatography was performed on a YMC ODS AM-312 column (6 mm i.d., 150 mm) with a mobile phase consisting of water and acetonitrile (6:4). Recoveries of dithiocarbamates from samples at the level of 1 ppm were more than 70% except for one combination. The determination limits of dithiocarbamates were all 0.05 ppm.