Supercritical fluid extraction as a cleanup technique for gas chromatographic analysis of pesticides in wool wax

Supercritical fluid extraction with CO2 was investigated as a sample cleanup procedure for the gas chromatographic analysis of pesticide residues in wool wax. Spiked samples were used to optimize the extraction parameters. Recoveries of between 85% and 108% with relative standard deviations of 2-8% were obtained for a range of pesticides that represented those most likely to be found in raw wool wax as a result of treating sheep with legal pesticides to control ectoparasites.