An Enzymic Method for the Determination of Inorganic Phosphate in Urine

Abstract

An enzymic method for the determination of inorganic phosphate in urine was established, based on the formation of hydrogen peroxide with purine nucleoside phospho rylase (PNP) and xanthine oxidase (XO).
Inosine+H₃PO₄ PNP→hypoxanthine+ribose-1-phosphate Hypoxanthine+2H₂O+2O₂XO→uric acid+2H₂O₂ H₂O₂+red. chromogen peroxidase→oxid. chromophore+ H₂O
The method was evaluated by the investigation of its precision, accuracy, sensitivity and specificity. It was concluded that this method was useful in clinical tests for the determi nation of inorganic phosphate in urine.