Determination of Thiocyanate with Cuprous Ion Selective Electrode

A new Cu(Ⅰ)-selective electrode was prepared by using a mixture of bathocuproin and carbon paste as sensitive film and paraffin wax as binder. Based on the formation of a stable complex between SCN- and Cu+, an indirect method for determination of SCN- with the Cu(Ⅰ)-selective electrode was proposed. It was found that in 0.01 mol·L-1 sodium citrate solution of pH 6.2 excellent selectivity and potential response toward SCN- (indirectly) were achieved by the ion selective electrode, which showed Nernst potential response in the range of 1.0×10-7 to 1.0×10-3mol·L-1 SCN-. Recovery was tested by standard addition method using sample of chemical waste water as matrixes, results of recovery found were in the range of 96.7%-101% with RSD′s (n=7) in the range of 2.2%-5.5%.