Abstract
A capillary column gas chromatography/mass spectromertic procedure is described for the determination of molinate, which is a representative thiocarbamate paddy herbicide, in environmental samples. A liquid-liquid extraction method with hexane is applied to the separation and concentration of molinate residues in water samples. On the other hand, the pretreatment technique for sediment and fish samples is combined with steam distillation and column chromatography using a Sep-Pak Florisil cartridge. The detection limits in water, sediment and fish samples are 12ng/l, 380ng/kg and 520ng/kg, respectively. The recoveries of molinate from water samples spiked (60ppt) and sediment samples spiked (3ppb) are more than 90%, and those from fish samples spiked (3ppb) are about 80%. This method enables the reliable determination of molinate residues in environmental samples at ppt or ppb level.
