Titrimetric and Spectrophotometric Methods for the Determination of Glyoxal and Analysis of Ternary Mixtures of Its Oxidation Products

Abstract

Using thallium(III) as an oxidant, we developed titrimetric and spectrophotometric methods for the estimation of glyoxal at mmole and µ mole levels, respectively. In the titrimetric method, thallium(I) formed is determined oxidimetrically with potassium bromate. In the spectrophotometric method, the absorbance of thallium(III) at 260 nm in the presence of 0.1 mol/L sodium chloride and 1.0 mol/L perchloric acid is measured. A plausible mechanism for the oxidation of glyoxal is proposed. Based on the selective oxidation of the probable oxidation products of glyoxal (namely, glyoxylic acid, formic acid, and oxalic acid), a convenient titrimetric method is described for analyzing ternary mixtures of these products.