Voltammetric Determination of Rubeanic Acid

Procedures for the voltammetric determination of rubeanic acid (RA) at a mercury-film electrode were proposed. They are based on the oxidation of RA at –0.70 to –0.80 V or on the reduction of mercury sulfide, the product of RA oxidation, at –0.82 to –0.85 V (versus a saturated silver–silver chloride electrode) in a 1 M NaOH solution. The oxidation and reduction currents are linear functions of RA concentration in the ranges from 9 × 10–6 to 3 × 10–4 M and from 5 × 10–6 to 3 × 10–4 M, respectively.