Insecticide Measurement, Determination of Toxaphene by a Spectrophotometric Diphenylamine Procedure

Abstract

A confirmatory method for the positive identification of toxaphene in small residues has not previously been reported. A sensitive method for the qualitative and quantitative determination of toxaphene in residues and in formulations is based on fusion with diphenylamine in the presence of zinc chloride. The greenish blue reaction product, dissolved in acetone or glacial acetic acid, has an absorbance maximum at 640 mp. Toxaphene in the range of 20 to 700 y can be readily determined b y spectrophotometric measurement. When combined with cleanup procedures, the method has been applied to extracts of crops and foods and to various formulations, including mixtures with sulfur or DDT.HE need for an accurate method for T the specific determination of micro quantities of toxaphene in food and forage crops and in milk and beef has become increasingly apparent with the more widespread use of this insecticide. Toxaphene is chlorinated camphene containing 67 to 69% chlorine. Microdetermination by a sensitive method for organic chlorine (5) has been widely used for determining toxaphene residues, but this method lacks specificity. Macrodetermination by an infrared method ( 4 ) is specific, but has not been employed as a residue method because of Ion sensitivity. A qualitative colorimetric test with pyridine and methanolic potassium hydroxide has been reported ( 3 ) .

Insecticide Residues, Toxaphene Residues on Pangolagrass

“…All samples were analyzed by the colorimetric diphenylamine procedure for toxaphene (4), with minor modifications. Chromatographic columns used for cleanup were 19 mm.…”

Diphenylamine-Zinc Chloride as a Chromogenic Agent for the Detection of a Mixture of DDT, Chlordane, and Toxaphene on Thin Layer Chromatograms

“…McKinley and Graham (12) used diphenylamine-ZnCl 2 to identify captan on paper chromatograms. Cueto (13) employed this reagent for the colorimetric determination of dieldrin, and Graupner and Dunn (14) used it for the colorimetric determination of toxaphene. These authors also reported on colors given by pesticides other than those for which they developed methods.…”

“…The objective of the present study was to find the chromogenic agent that would best distinguish toxaphene, DDT, and chlordane in combination when they are chromato-graphed on thin layer plates. The literature cited above (11)(12)(13)(14) showed that diphenylamine-ZnCl 2 gave various colors with a number of chlorinated pesticides; therefore, this reagent was investigated. The results reported here were obtained by applying diphenylamine-ZnCl 2 to chlorinated pesticides on Al 2 0 a plates.…”

Pesticides

“…Graupner and Dunn (21) have reported a method for determining residues of toxaphene by means of fusion with diphenylamine in the presence of zinc chloride. The reaction product from the fusion was dissolved in acetone or glacial acetic acid and determined spectrophotometrically.…”