Supercritical Fluid Extraction of Sulfonylurea Herbicides in Soil Samples

Abstract
The application of supercritical fluid extraction (SFE) with supercritical CO2 to the analysis of 2 sulfonylurea herbicides in 4 soils is presented. Methanol and water are added to the soil samples as modifiers. After extraction, Chlorsulfuron and Metsulfuron methyl are measured by HPLC-UV at 220 nm. The recovery rates are good (>80%) for all types of the studied soils except for those with high organic carbon content (ca. 50%). According to the characteristics of the soils, recovery with SFE is similar or better than with liquid-solid extraction.