Determination of Gaseous Hydrogen Sulfide by Cathodic Stripping Voltammetry after Preconcentration on a Silver Metalized Porous Membrane Electrode

摘要

Gaseous H2S is accumulated on the surface of a porous silver membrane electrode at constant potential and directly determined by cathodic stripping voltammetry. The sensitivity of the method, expressed by the slope of the regression line for the dependence of the stripping peak current on the amount of H2S in the gas sample, is 357 micrograms of H2S/micro Amps. The reproducibility of the determination expressed in terms of the relative standard deviation is 3.2%. Phenomena observed during cathodic polarization of the silver porous membrane electrode, either clean or covered with deposited Ag2S, are briefly discussed and the resultant conditions for optimal analysis are given.