A NEW SULFATE ION SENSITIVE ELECTRODE

Designing a new material to fabricate electrodes sensitive to ion spec ies of specific interest is the main stream in the ion sensitive elect rode research. The research efforts of the present authors have been d irected, in particular, to the development of a phosphate ion sensitiv e electrode based on non-stoichiometric compound Co1-xO and a Cu2+ ion sensitive electrode based on LaB6. In this paper, a new sulfate ion s ensitive electrode is reported based on non-crystal Ni-P alloy, which has a very nice response characteristics including stability, selectiv ity and linear response range, The electrode shows a linear range of r esponse from 1X10(-6) to 1X10(-2) mol/L and a detection limit of 4X10( -7)mol/L for the sulfate;ion. The selectivity coefficients for common anions Cl-, NO3-, H2PO4-, Br- and I- are obtained as 2X10(-1), 8X10(-5 ), 8X10(-3), 3X10(-1) and 4X10(-1), respectively, The electrochemical deposition of the non-crystal Ni-P alloy on different matrix materials has been described for preparation of the titled electrode.