Determination of BHC in a mixed dust of DDT and BHC: Separation and determination of a mixed drug by vapor-chromatography. I

The values of determination of BHC separated by use of the author's apparatus (Fig. 1) do not contain factors which induce errors by the presence of DDT (Table II and III). An improved dechlorination method gives result agreeable with that from the theoretical value (Table I) without using any correction factor. The powdered mixture is extracted with ether, the ether is removed, the residue containing DDT and BHC is treated with alcoholic potassium hydroxide solution to convert BHC into trichlorobenzene. The solution containing trichlorobenzene is held in a column of globular alumina at 100°C and water vapor is passed in for distilling off trichlorobenzene (Fig. 1, the water vapor chromatographic apparatus). The trichlorobenzene is taken up in petroleum benzine, treated with metallic sodium and n-butanol, the petroleum benzine distilled off and the dechlorination is completed by further heating with controlled temperature. The solution is acidified with nitric acid and the chlorine in aqueous layer is determined by the Volhard method, from the value of which the amount of BHC is calculated.