Cathodic stripping voltammetry of 2-mercapto-5-methyl-1,3,4-thiadiazol and 2,5-dimercapto-1,3,4-thiadiazol at a controlled-growth mercury drop electrode

摘要

2-Mercapto-5-methyl-1,3,4-thiadiazol (MMTD) and 2,5-dimercapto-1,3,4-thiadiazol (DMTD) were studied by differential pulse cathodic stripping voltammetry (DPCSV). The influence of buffer, pH, accumulation potential (E-acc), and accumulation time (t(acc)) was investigated. It was stated that the concentration of the buffer affects the height of DPCSV peaks. The best analytical signals were recorded in acetate buffer at pH 4.3 and a buffer concentration of 0.01 mol/L for MMTD and 0.02 mol/L for DMTD, E-acc = 0.2 V, and t(acc) = 120 s for MMTD and 180 s for DMTD. A linear dependence was found from 1 to 8 X 10(-8) mol/L for MMTD and from 1 X 10(-8) to 1 X 10(-7) mol/L for DMTD. The influence of cations [Cu(II), Co(II)] was also considered.