Determination of Ge in Au alloys using sodium hypophosphite and potassium iodate potentiometric titration method

This paper presents a new method of determining Ge in AuGe alloys by potassium iodate(KIO3)potentiometric titration when Ge(Ⅱ)and Au(0)are simultaneously reduced from Ge(Ⅳ)and Au(Ⅲ)by sodium hypophosphite rather than by distillation separation.The influences of such conditions as the reduction acidity,the dosage of sodium hypophosphite and the reduction time on the determination of Ge were studied.Ge in AuGe alloys such as AuGe_(12),AuGeNi_(12-2),AuAgGe_(18.8-12.5),and AuAgGeNi_(43.8-6-0.2)was measured with the relative standard deviation(RSD)of 0.10%-0.31%and the recoveries of added standard Ge in sample of 99.40%-100.40%under the conditions of 0.40-0.80 mol·L^(-1)HCl,3.3 mol·L^(-1)H^(3)PO^(4),15 g sodium hypophosphite,and reduction time of40 min.The new method presented is of high accuracy in results,good stability and sensibility in end-point,and easy operation and strong selectivity of determination.