Measurement of purine derivatives in urine of ruminants using automated methods

Abstract Automated methods based on the Auto Analyzer have been developed for the analysis of allantoin, uric acid and xanthine plus hypoxanthine in urine of sheep and cattle. Allantoin is determined by a modification of an existing method. Recovery of allantoin added to urine was 99.7% ± 3.2 SD. Uric acid is determined using a phosphotungstic acid method, and xanthine and hypoxanthine together are determined as uric acid after treatment with xanthine oxidase. The enzymic conversion is integrated into the automated procedure of uric acid analysis. Recovery of uric acid, xanthine and hypoxanthine, all as uric acid, was 97–99%. The relative proportions of allantoin: uricacid: xanthine plus hypoxanthine in urine of sheep differed from those in urine of cattle. Xanthine and hypoxanthine were almost absent from urine of cattle.