RAPID MULTIRESIDUE PROCEDURE FOR THE DETERMINATION OF PESTICIDES IN ANHYDROUS LANOLIN AND LANOLIN-CONTAINING PHARMACEUTICAL PREPARATIONS UTILIZING GEL-PERMEATION CHROMATOGRAPHY CLEANUP WITH GAS-CHROMATOGRAPHIC AND MASS-SPECTROMETRIC TECHNIQUES

The proposed multiresidue method has been used to quantify residues of 17 different pesticides found in anhydrous lanolin and lanolin-containing pharmaceutical preparations. Lanolin waxes are separated from the residues using automated gel permeation chromatography (GPC). Resulting eluates are injected directly into gas chromatographs using a variety of wide-bore capillary columns. A flame photometric detector in the phosphorus mode (FPD/P) is used to quantify organophosphorus pesticides. Organochlorine residues are determined through the use of electrolytic conductivity detection (ELCD). Several residues were identified or confirmed using GC with mass spectrometry. Results of analysis of samples of anhydrous lanolin collected in 1991 were similar in types and levels of residues to those analyzed in 1989. Diazinon residues were most prominent, with levels frequently in excess fo 20 mg/kg. Additionally, some lanolin-containing pharmaceutical preparations collected in 1988 and 1992 were found to have patterns of residues similar to those encountered in anhydrous lanolin. However, the highest level of residues encountered in these preparations was only 6.82 mg/kg (diazinon). Recoveries from anhydrous lanolin samples fortified with 12 organochlorine and organophosphorus pesticides ranged from 97 to 110%.