Spectrophotometric determination of micro amounts of cadmium in waste water with cadion and triton X-100

Abstract

A spectrophotometric method for determination of micro amounts of cadmium in waste water with Cadion and Triton X-100 is described. The interference of foreign ions can be eliminated by masking with an ascorbic acid—Rochelle salt—potassium cyanide—potassium fluoride mixture. After demasking with formalin, cadmium is determined directly in aqueous solution without separation. Beer's law is obeyed for 0–8 μg of Cd in 25 ml of solution. The method is more sensitive than the dithizone method, its apparent molar absorptivity at 480 nm being 1.19 × 10 5 1. mole −1. cm −1. Results obtained by using the proposed method on waste water samples agree well with those obtained by atomic-absorption spectrophotometry.