Voltammetric determination of reducing agents and dyestuffs in textile printing pastes

Summary Basic research concerning voltammetry in highly viscous, paste-like systems is presented. Using model compounds for dyestuffs and reducing agents, respectively, the principal applicability of electrochemical techniques for direct quantitative determination of electroactive compounds in such media is proved. The influence of non-Newtonian viscosic properties of the thickeners used (polygalactomannanes, carboxymethylcellulose) on current voltage curves obtained with rotating electrodes is discussed. An increase of the anodic measuring range due to electrode surface modification by the products of the electrode reaction of hydroxymethanesulphinate and by the properties of the thickeners is evaluated.