DETERMINATION OF TETRAMETHYLTHIURAM DISULFIDE (THIRAM) IN RIVER WATERBY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY - MICELLAR VERSUS CONVENTIONAL REVERSED-PHASE CHROMATOGRAPHY

After a comparative study of conventional reversed phase and micellar liquid chromatography a method is described for the determination of t he fungicide thiram in river water based on the use of micelles of CTA B. The method involves the extraction/concentration of thiram with a C -18 cartridge followed by separation on a C18 reversed-phase column wi th a mobile phase of 20 % (v/v) acetonitrile/0.01 M CTAB in phosphate buffer (pH = 6.3), and detection at 254 nm. The method allows the dete rmination of thiram in the presence of other water-soluble dithiocarba mate fungicides (nabam, ziram and ferbam) with a limit of detection of 36 pg mL(-1) for a typical 20-fold preconcentration.