Liquid chromatographic determination of triasulfuron in soil

Two extraction methods were developed for the determination of triasulfuron in soil. Method I included extraction with methanol-phosphate buffer at pH 7 (2 + 1, v/v), liquid-liquid partition with dichloromethane, and cleanup on a liquid chromatographic Si adsorption solid-phase extraction tube. In M ethod II, Extrelut was added and the sample was then extracted with acetoni trile, In both cases, the extracts were analyzed by liquid chromatography ( LC) with UV detection and the LC peak was confirmed by LC/mass spectrometry (MS), The 2 methods were tested on 3 soils having different physicochemica l characteristics. Method I gave 83% average recovery and a determination l imit of 0.4 mu g/kg soil. Method II gave 67% average recovery and a determi nation limit of 2 mu g/kg soil. Examples of application of Method I to fiel d samples are reported.