摘要:Presence of mercury interferes in the spectrophotometric determination of cadmium by the dithizone method. For the elimination of mercury, the acid-digested sample solution was extracted with the chloroform solution of dithizone before neutralization. By this procedure, mercury was removed from the aqueous layer without loss of cadmium. It is usually described in the literature that cadmium is extracted repeatedly with the chloroform solution of dithizone until organic layer becomes colorless, but the organic layer was colored even after repeating extraction more than five times and the decolorization of the organic layer was not a satisfactory index of the end-point of extraction. From the present experiment, three extractions were sufficient for complete extraction of cadmium.