Determination of sulfonylurea degradation products in soil by liquid chromatography-ultraviolet detection followed by confirmatory liquid chromatography-tandem mass spectrometry

A method based on liquid extraction followed by sample enrichment on reversed-phase solid-phase extraction was developed for the extraction of five degradation products of four sulfonylurea herbicides (chlorsulfuron, metsulfuron-methyl, thifensulfuron-methyl and tribenuron-methyl) from soil. The compounds have been quantified by LC–UV and identified by tandem LC–MS with electrospray ionization or atmospheric pressure chemical ionization. The limits of detection for the five compounds were between 10 and 50 μg kg−1. The method has been applied to the extraction of soil samples after microbial degradation of sulfonylurea herbicides.