Use of supercritical fluid extraction in the analysis of pesticides in soil

The applicability of supercritical fluid extraction (SFE) in pesticide resi due analysis in soil was investigated by analysing real soil samples from f ield experiments. Additionally, radiotracer batch experiments were performe d to study the release of non-extractable residues. High repeatability, acc uracy and high selectivity were the most important advantages of SFE in res idue analysis. Extracts with low amounts of coextractants from the soil mat rix were achieved, allowing extracts to be pooled and concentrated without further clean up steps. Thus, the limited volume of extraction thimbles of the SEE apparatus used could be compensated and insufficiently high limits of determination could be improved. Although the application of methanol-mo dified supercritical CO2 was a time-saving extraction procedure which reduc ed solvent usage and solvent waste, SFE efficiency proved only competitive to conventional slurry and Soxhlet extraction. No exhaustive release of non -extractable residues was achieved in radiotracer batch experiments. (C) 20 00 Elsevier Science B.V. All rights reserved.