Collect. Czech. Chem. Commun. 1996, 61, 663-672

Polarographic and Voltammetric Determination of 4,4'-Bis[(4-diethanolamino-6-(2,5-disulfophenylamino)-1,3,5-triazin-2-yl)amino]stilbene-2,2'-disulfonic Acid

Jiří Bareka, Roman Hrnčířb, Josino C. Moreirac and Jiří Zimaa

a UNESCO Laboratory of Environmental Electrochemistry, Department of Analytical Chemistry, Charles University, 128 40 Prague 2, Czech Republic
b Severochema Cooperative, 461 71 Liberec, Czech Republic
c CESTEH/ENSP/FIOCRUZ, Rua Leopoldo Bulhoes 1480, Manguinhos, 210 41-210 Rio de Janeiro, Brazil


The polarographic and voltammetric behaviour was studied for 4,4'-bis[(4-diethanolamino-6-(2,5-disulfophenylamino)-1,3,5-triazin-2-yl)amino]stilbene-2,2'-disulfonic acid, which is the basis of many commercial optical whitening agents. The optimum conditions were found for quantitation of this substance in tetraethylammonium bromide solutions in dimethylformamide containing 5% (v/v) water using TAST polarography, differential pulse polarography, linear sweep voltammetry at a hanging mercury drop electrode, and differential pulse voltammetry at a hanging mercury drop electrode over the concentration regions of 100-500, 10-500, 10-500, and 1-100 mmol l-1, respectively. The practical applicability of the new analytical methods to the determination of the substance in technical products was verified.

Keywords: Polarography; Voltammetry; Optical brightening agents; 4,4'-Bis[(4-diethanolamino-6-(2,5-disulfophenylamino)-1,3,5-triazin-2-yl)amino]stilbene-2,2'-disulfonic acid.