Preparation and study of new ion selective electrode for determination of cadmuim based 1,3-dipheny l-5- (P-nitrophenyl) formazan as ionophore

A new polyvinylchloride membrane sensitive to Cd+2 ions basede on 1,3-diphenyl-5-P-nitrophenylformazan as ionophore has been prepared. This electrode shows a Nernestian response for cadmuim ions over a wide range ( 1.0 ×10-6 to 1.0 ×10-1 M ) with the slope of 27.74 mv . decade-1 . the detiction limite is 7 × 10-7 M . It has a fast response time of 15 s and can be used for at least 4 mounth without any divergence in potential . the electrode can be used in the pH range from 4.0 to 9.0 . the proposed electrode shows avery good discriminating ability towards Cd+2 ion in presence of some alkali , alkaline earth , transition and heavy metal ions. It was successfully applied for the direct determination of Cd+2 in standard and real sample solutions