Study of Extraction Procedures for Chlorinated Organic Pesticides in Fresh Eggs

The Johnson procedure was modified to provide a quicker and more satisfactory method for cleanup of fresh egg samples for chlorinated pesticide residue analysis. Acetonitrile extraction of the sample was followed by centrifugation of the extract and chromatography on a “layered” Florisil sodium sulfate column. The use of the “layered” column yielded 15% eluates suitable for direct analysis by microcoulometric gas chromatography. Unfortified egg samples were analyzed for DDD, DDE, DDT, heptachlor epoxide, and dieldrin by both this procedure and the Onley-Mills technique, and the results were compared.

Pesticide Residues in Total Diet Samples

Total diet samples collected since August 1962 were analyzed for the presence of chlorinated organic pesticides, parathion, and 2,4-D types of herbicides and plant growth regulators. Chlorinated pesticide residues were identified by paper, gas-liquid, thinlayer, and microcoulometric gas chromatography. Parathion residues were identified by polarography and confirmed by paper chromatography. Organophosphate pesticide residues were noted in a few samples by paper chromatography. No herbicides were detected in any samples.

Sensitivity Tests for 22 Different Chlorinated Organic Pesticides by Paper Chromatography

This paper reports minimum quantities, in micrograms, of 22 organic chlorinated pesticides that can be detected by the silver nitrate/2-phenoxyethanol chromogenic agent, both before and after chromatographing, and after the papers have been washed with water to remove excess silver nitrate.