Determination of Chlorinated Pesticide Residues in Fat by Electron Capture Gas Chromatography

Abstract

A general screening method has been developed for the cleanup and estimation of chlorinated pesticide residues in fats and oils. The fats were dissolved in benzene-acetone (1 + 19) and then precipitated at — 70 °C. The precipitated fat was removed by filtration through a column of Darco G-60 and Solka Floe in a jacketed filtering funnel. The filtrate was concentrated to a standard volume and an aliquot was analyzed by electron capture gas chromatography. With the exception of a few pesticides in butterfat and aldrin in beef fat, recoveries were 81 to 112% after a mixture of 12 chlorinated pesticides had been added to the fats prior to precipitation. A Pyrex gas chromatographic column containing a 10% stationary phase of mixed silicones (4% SE-30 methyl silicone + 6% QF-1 fluoro silicone) was used to resolve this pesticide mixture. The compounds eluted from the column in the following order: lindane, heptachlor, aldrin, Telodrin, heptachlor epoxide, p,p’-DDE, dieldrin, o,p’-DDT, Rhothane, p,p’-DDT, endrin, and methoxychlor.

Gas chromatographic determination of chemical residues in food, using a rugged high-resolution mixed-bed column

“…Analytical methodology for determining these analytes at ambient concentrations is indeed only poorly developed, and emphasis in environmental studies has been given so far to measurements of the tetraalkyllead (PbR4) compounds. For the latter, the combination of gas chromatography with an element-specific detection system was proven to be very successful (1)(2)(3)(4)(5)(6). This approach has been attempted also in the case of the trialkyllead compounds despite their low vapor pressure, thermal instability, and chemical reactivity, which make a direct quantitative gas chromatographic analysis extremely difficult (7).…”

“…Adding the OV-225 phase bed to the packing mixture caused these compounds to merge; adding the OV-101 phase bed caused them to separate up to 1 min. The third control point, the RRC of , '-DDT at 200 °C, ranged 5.00 ng of p ,p '-methoxychlor.…”

Low temperature cleanup procedure for pesticides and their metabolites in biological samples

“…The combination contains a watermiscible solvent (acetone) and has been used for extracting organochlorine residues by McCully and McKinley (1964a). In addition, acetone has been used with other solvents such as hexane and ethyl ether for extracting many different pesticides and their metabolties: e.g., aldrin, a cyclodiene by Goodwin et al (1961); phygon, a dichloronaphthaquinone by Burchfield and McNew (1948); dichlobenil, a dichlorobenzonitrile by Beynon et al (1966); 2,4-D, a dichlorophenoxy acid by Burchfield and McNew (1948); Zectran, an V-methyl carbamate by Niessen and Frehse (1963); and paraoxon, a diethyl p-nitrophenyl phosphate by Bates (1965).…”

Efficiency of extraction of metabolically incorporated HEOD (carbon-14) from pheasant tissues, eggs and faeces

“…The second half of each mixture was extracted and purified by using the Florid-column method of Stemp, Liska, Langlois and Stadelman. 4 The mixture was placed on top of 40 g of Florisil in a 20 x 400-mm column, and the HEOD eluted with 750 ml of 20 per cent. v/v dichloromethane in light petroleum.…”