Supercritical Fluid Extraction of Naled, Methyl Eugenol, and Cuelure in Soil

Supercritical fluid extraction procedures are developed for the analysis of naled, methyl eugenol, and cuelure in soil samples. Recoveries of analytes from soil spiked at 0.25–45 μg/g levels are high using modified or unmodified carbon dioxide (CO2) at 60°C. For methyl eugenol, recoveries of 91–101% are obtained using CO2, a pressure of 27.6 MPa, and 5–30% soil moisture. For naled, recoveries of 65–90% are obtained using ethyl acetate modified CO2, a pressure of 48.3 MPa, and 10–30% soil moisture. For cuelure, total recoveries of 76–95% are obtained with acetone-modified CO2 using a pressure of 41.4 MPa and 10–30% soil moisture. Recoveries are also high for dichlorvos (85%) and raspberry ketone (81%), which are degradation products of naled and cuelure, respectively, in soil spiked at 45 μg/g under optimized conditions. Cuelure was derivatized to raspberry ketone and quantitatively recovered by supercritical fluid extraction. Recoveries of naled, methyl eugenol, and cuelure from soil by supercritical fluid extraction were comparable with those of conventional solvent extraction procedures using methylene chloride or ethyl acetate modified acetonitrile. Application of optimized SFE conditions for the soil dissipation study of naled, methyl eugenol, and cuelure under laboratory conditions showed that supercritical fluid extraction is convenient, fast, and uses much less solvent relative to conventional solvent extractions.