AMPEROMETRIC FLOW-INJECTION DETERMINATION OF GLUCOSE, URATE AND CHOLESTEROL IN BLOOD-SERUM BY USING SOME IMMOBILIZED ENZYME REACTORS AND A POLY(1,2-DIAMINOBENZENE)-COATED PLATINUM-ELECTRODE

Glucose, uric acid and cholesterol in blood serum were assayed simulta neously in a flow-injection system by using a 16-way switching valve a nd a parallel configuration of three immobilized enzyme re actors. A p oly(1,2-diaminobenzene)-coated platinum electrode was used to detect s electively hydrogen peroxide generated enzymatically into the enzyme r eactors, without any interferences from oxidizable species and protein s present in serum. The precision (coefficient of variation) of the as say was better than 2% for the simultaneous assay of three species in human control serum. The assay speed was up to 38 samples per hour.