Quantification of urinary oxalate with alkylamine glass bound Amaranthus leaf oxalate oxidase

A method has been developed for discrete analysis of urinary oxalate employ ing alkylamine glass bound oxalate oxidase partially purified from mature l eaves of Amaranthus spinosus. In the method H2O2 is generated from urinary oxalate by immobilized oxalate oxidase, which is measured by a colour reage nt containing 4-aminophenazone, phenol and horseradish peroxidase in phosph ate buffer, pH 7.0. The chromogen formed is read at 520nm. The minimum dete ction limit of the method is 0.9mg/L. The analytical recovery of added oxal ate in urine was 98.0+/-2.7% (mean+/-SD). Within batch and between batch CV 's were less than 4% and 3%, respectively, for urinary oxalate determinatio n. The mean value of urinary oxalate measured by the present method is comp arable to that obtained by the Sigma kit method (r=0.98).