Quantification of Urinary Oxalate with Alkylamine Glass Bound Amaranthus Leaf Oxalate Oxidase

Abstract

ABSTRACT A method has been developed for discrete analysis of urinary oxalate employing alkylamine glass bound oxalate oxidase partially purified from mature leaves of Amaranthus spinosus. In the method H2O2 is generated from urinary oxalate by immobilized oxalate oxidase, which is measured by a colour reagent containing 4-aminophenazone, phenol and horseradish peroxidase in phosphate buffer, pH 7.0. The chromogen formed is read at 520nm. The minimum detection limit of the method is 0.9mg/L. The analytical recovery of added oxalate 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 determination. The mean value of urinary oxalate measured by the present method is comparable to that obtained by the Sigma kit method (r=0.98).