Separation and polarographic determination of cadmium in stainless steel

Abstract

A method has been developed for the determination of small amounts of cadmium in stainless steel. Cadmium and copper are initially separated from other elements with thioacetamide. After extraction of the copper with Neocuproïne in chloroform, cadmium is determined polarographically in an ammonium chloride-aqueous ammonia electrolyte. Over the range 0.001–0.01 % of cadmium, results are accurate to within 10% of the amount present. As little as 0.0005% of cadmium may be determined, and the upper limit may be extended beyond 0.01% by using smaller samples or by aliquoting. This method may be applied to all commercial grades of stainless steel.