The determination of hydroxypyruvate and glycolaldehyde

Abstract

A colorimetric method for the determination of hydroxypyruvate and glycolaldehyde is described. The intensity of the green color obtained on heating the solution with naphtharesorcinol in 23 N H2SO4, measured at 660 m[mu], is proportional to the amount of these substances present under the defined conditions of the test. When both substances are present together the estimation is repeated after adsorption of hydroxypyruvic acid on Bio-Deminrolit G. The specificity of the test has been studied, and certain interfering substances are noted. Modifications permitting the estimation of glyceric acid and of glyoxylic acid are indicated. The use of hydroxypyruvate reductase from parsley leaves and lactic dehydrogenase of muscle for enzymic assay of hydroxypyruvate is described. Whereas the former enzyme reacts only with hydroxypyruvate, the latter reduces pyruvate also and the two enzymes may therefore be used in conjunction for quantitative analysis of mixtures of these two keto acids.