Nickel(II) ion-selective electrode based on 2,5-thiophenyl bis(5-tert-butyl-1,3-benzoxazole)

A PVC membrane sensor for Nickel (II) ions based on 2,5-thiophenyl bis(5-te rt-butyl-1,3-benzoxazole) as membrane carrier was prepared. The sensor exhi bits a Nernstian response for Ni2+ ions over a wide concentration range (10 (-2)- 10(-5)M). It has a relatively fast response time and can be used for at least 2 months without any considerable divergence in potentials. The na ture of the plasticizer, the additive, the concentration of internal soluti ons in the electrodes and the composition of the membrane were investigated . The proposed membrane electrode revealed very good selectivities for Ni2 over a wide variety of other metal cations and could be used in pH range o f 4.0-8.0. It was successfully applied for the direct determination of Ni2 in solution and as an indicator electrode in potentiometric titration of n ickel ion in both water and 85% acetonitrile solutions.