The electropolymerization of 2,6-Diaminopyridine and its application as mercury Ion selective electrode

摘要

A composite graphite (CG) electrode modified with poly(2,6-diaminopyridine) (PDAP) was used as solid state-ion selective electrode for determination of mercury. The electrooxidation of monomer 2, 6 diaminopyridine (DAP) onto CG was accomplished from the 30 mM DAP in 5% H_2SO_4 and 0.5 M ZnSO_4. The electrode displayed Nernstian response with slope of 28.4±1 mV decade ~1 in concentration range of 1×10~(-6) to 1×10~(-1) M and in solution of pH 3-5. The limit of detection for electrode was 3×10~(-8) M with response time of 25 s. The electrode was also suitable as an indicator electrode in the potentiometric titration of Hg~(2+) with iodide.