PVC-based cobalt and manganese phthalocyanine coated graphite electrodes for determination of thiocyanate

Thiocyanate selective electrodes were prepared by incorporating cobalt and manganese phthalocyanines into plasticized ploy(vinyl chloride) membranes w hich were directly coated on the surface of graphite electrodes. A calibrat ion plot with Nernstian slope for thiocyanate was observed over a linear ra nge of five decades of concentration (1x10(-6)-1x10(-1) M). The electrode h as a fast response time, very low detection limit (5x10(-7) M thiocyanate), is easy to prepare, and could be used for over a month. The proposed senso r revealed good selectivity for thiocyanate over several anions and could b e used over a wide pH range. Applications of the electrode to the potentiom etric titration of silver ion with thiocyanate and determination of thiocya nate in urine samples are reported.