New Polymeric Membrane Sensor Doped With N,N '-Bis(Benzoin)-1,2-Phenylenediamine For Selective Determination Of Aluminum

A new polymeric membrane sensor for Al3+ based on bis(benzoin)-1,2-phenylenediamine as a neutral carrier was investigated. The proposed sensor exhibits a near-Nemstian response for Al3+ over a wide linear range of 3.0x10(-7) to 1.0x10(-1) mol/L, with a detection limit of 1.0x10(-7) mol/L and a slope of 19.7 +/- 0.3 mV/decade. The sensor displays a good selectivity toward Al3+ over other cations in pH range of 2.5 to 4.0. It has relatively fast response time (8 s) and can be used at least for 3 months without considerable divergence in potential. The response mechanism was discussed in view of the A.C. impedance technique. It was successfully used as an indicator electrode in the determination of aluminum in real samples.