Determination of trace amounts of carcinogenic substances: Adsorptive stripping voltammetry of 1-[4′ -(phenylazo)phenyl]-3,3-dimethyltriazene at a hanging mercury drop electrode

1-[4′-(Phenylazo)phenyl]-3,3-dimethyltriazene can be determined in the range from 1 × 10^-5 to 2 × 10^-7 mol dm 3 by direct current or differential-pulse voltammetry at a hanging mercury drop electrode. Direct current adsorptive stripping voltammetry can be used in the range from 2 × 10^-8 to 10 × 10^-8 mol dm ^-3 and differential-pulse adsorptive stripping voltammetry in the range from 1 × 10^-8 to 2 × 10^-11 mol dm ^-3. The extremely high sensitivity in the latter instance was achieved by using 200-fold diluted Britton-Robinson buffer as a base electrolyte together with a long accumulation time (up to 30 min at 1 × 10 ^-11 mol dm 3). The relative standard deviation (seven determinations at 2 × 10^-11 mol dm^-3) was 8.6%.