Abstract
The activity of alkaline phosphatase in serum was determined by measuring the increase in current for a given time due to the oxidation of phenol, as enzymatically released from phenyl phosphate, with a dialysis membrane-covered glassy-carbon electrode. The activities determined amperometrically for thirty serum samples were in excellent agreement with those determined using a colorimetric method (correlation coefficient of 0.996). The electrode is free of deactivation of electrode surface by the protein adsorption typically encountered when an electrode without a dialysis membrane is employed. The electrode can be used repeatedly without appreciable degradation of its sensitivity. The present method is applicable to samples containing significant amounts of oxidizable substances.
