Ion Selective Electrodes Based on Brilliant Green Tetrathiocyanatezincate(II)

Abstract

Liquid state, heterogeneous silicone rubber and carbon paste electrodes based on Brilliant green tetrathiocyanatozincate(II) have been prepared and studied. The liquid state electrode, consisting of a 10⁻³ M solution of Brilliant green tetrathiocyanatozincate(II) in o-dichlorobenzene supported on lightly cross-linked natural rubber, was the most satisfactory. This electrode responded rapidly when placed in 10⁻⁴ to 10⁻¹ M solutions of zinc containing a twenty-fold excess of thiocyanate. The potential concentration slope (-29.5 mV per decade change in concentration) was that 2-expected for response to Zn(SON)₄ ²-. The silicone-rubber and carbon paste electrodes also gave near-Nernstian response, but responded more slowly.

Key Words:

• ion-selective electrode
• zinc
• Brilliant green