Analysis of Metribuzin and transformation products in soil by pressurized liquid extraction and liquid chromatographic–tandem mass spectrometry

A method developed for study of metribuzin degradation in soil is presented. LC–MS–MS and electrospray ionisation was used for analysis of metribuzin and the metabolites deaminometribuzin (DA), diketometribuzin (DK) and deaminodiketometribuzin (DADK). Soil samples were extracted by pressurized liquid extraction using methanol–water (75:25) at 60°C. In general, recoveries were about 75% for metribuzin, DA and DADK and their detection limit in soil was 1.25 μg/kg. Lower sensitivity was observed for DK, with detection limit at 12.5 μg/kg and recovery about 50%.