Alumina blending technique for separation of pesticides from lipids.

An evaluation of an extraction technique for elimination of lipids during pesticide residue analysis was undertaken, which included a study of the parameters involved in an attempt to optimize the separation and recovery of selected pesticides from lipid samples. The choice of alumina, the degree of water deactivation of alumina, the amount of alumina relative to the weight of sample taken, the volume and composition of extraction solvent, the blending time, and the filtration procedure were all significant factors. Optimization of these factors resulted in greater than 90% recoveries of selected chlorinated pesticides from fortified fatty samples. In addition, the amount of co-extracted lipid material was about one-third of that obtained with the official method (AOAC 29.014), and less analytical time was required for the extraction by the proposed technique. The formation of troublesome emulsions sometimes encountered with the official method was also eliminated.