Continuous-flow potentiometric determination of α-amylase activity in serum and urine

An automated saccharogenic potentiometric method for serum or urinary α-amylase is described. Amylase is allowed to act on a buffered at pH 6.9 starch solution under controlled continuous-flow conditions and the reducing sugars produced are left to react with periodate. The consumption of periodate is monitored continuously with a newly constructed periodate-sensitive flow-through electrode. The endogenous reducing substances of serum or urine are measured with the same system by incubation of the sample with the same starch solution, at pH 4.7, in the presence of sodium fluoride as an amylase inhibitor. The difference in the reducing power (as glucose) is used to calculate the amylase activity of the samples. Values obtained with this assay correlate fairly well with those obtained with an amyloclastic method (r = 0.90-0.96). © 1985