Multiresidue analysis of pesticides in wool wax and lanolin using gel permeation and gas chromatography

The analysis of 48 different pesticide residues in raw wool wax and lanolin by the use of gel permeation and gas chromatography is described. The gel permeation conditions have been optimized for the recovery of the pyrethroids, which are currently widely registered for use on sheep to control ectoparasites. Coeluted wool wax peroxides, which were believed to be responsible for the initial failure of the narrow bore capillary gas chromatography columns used, were either removed or destroyed by passing the gel permeation eluant through alumina or by treatment with aqueous sodium metabisulfite. Wool wax was spiked with pesticides at three levels. Average recoveries at all levels ranged from 70% to 108%.