Collect. Czech. Chem. Commun. 1988, 53, 19-33

The polarographic and voltammetric determination of 2-amino-5-sulphoamoylnaphthalene-azo-(2’-chloro-4’-nitrobenzene)

Jiří Bareka, Jana Balsieneb, Antonín Berkaa, Ivana Hauserováa and Jiří Zimaa

a Department of Analytical Chemistry, Charles University, 128 40 Prague 2, Czechoslovakia
b Department of Organic Chemistry, Vilnius State University, 232 035 Vilnius, U.S.S.R.


The polarographic reduction of the title azo dye was studied, a mechanism was suggested and optimal conditions were determined for analytical utilization of this process. A detection limit of 3 . 10-7 mol 1-1 was obtained using fast scan differential pulse voltammetry and 0.7 . 10-7 mol 1-1 using linear potential scan voltammetry at a hanging mercury drop electrode. The detection limit can be decreased by adsorptive accumulation of the determined substance on the surface of the hanging mercury drop electrode, to 1 . 10-8 mol 1-1 for fast scan differential pulse voltammetry and 0.6 . 10-8 mol 1-1 for linear scan voltammetry. The selectivity of the determination can be improved by preliminary separation by extraction or thin-layer chromatography.