A New Rapid Spectrophotometric Method for Detection of Xanthinuria

Abstract

The purpose of this study was to develop a rapid procedure for detecting xanthinuria. In this hereditary defect there is a gross deficiency of the enzyme xanthine oxidase and the oxypurines, xanthine and hypoxanthine, replace uric acid in the urine. A number of enzymic spectrophotometry^1,2 and chromatographic^3,4 methods have been developed for determining these oxypurines but these methods are not readily available to most routine laboratories. The new procedure is based on the absorption maxima of hypoxanthine, xanthine and uric acid at 250, 270 and 292 nm respectively (Fig. 1). Because the urines of normal and xanthinuric subjects contain contrasting concentrations of these compounds, the possibility that the urinary absorption ratios 250/292 and 270/292 nm would be significantly different between the two groups was investigated.