Determination of tolclofos-methyl in soil and lettuce by gas chromatography

Two simple methods for the determination of tolclofos-methyl in soil and lettuce are presented. Soil samples were extracted with a methanol-water solution (9 + 1, v/v). The extract was cleaned up on a LC C-18 SPE cartridge. The method was tested on 4 soils having very different physico-chemical characteristics and gave recoveries > 70% and a determination limit of 0.02 mg/kg soil. Lettuce samples were extracted with n-hexane. The extract was cleaned up on florisil SPE cartridges. The recoveries were > 83% and the determination limit was 0.01 mg/kg lettuce.