Application of zetametry to determine concentrations of acidic and basic impurities in analytical reagents

The sign and magnitude of the zeta potential of mineral oxides in allegedly pure organic solvents (high-quality chemical reagents) depends on the conc entration of acidic and basic impurities, chiefly organic acids and amines, "Zetametric titration" with HClO4 makes it possible to estimate the concen tration of basic impurities and offers an attractive alternative to other a nalytical methods. Titanium(IV) oxide has been chosen as the probe powder i n view of its very low solubility and nearly neutral point of zero charge i n aqueous systems. Some systems have a high buffer capacity and addition of acid and base has a minor effect on the zeta potential of titania. Specifi c adsorption of alkali metal cations on anatase can be also a significant p roblem.