Potentiometric flow injection determination of amylase activity by using hexacyanoferrate(III)-hexacyanoferrate(II) potential buffer

Hiroki Ohura, Toshihiko Imato, Yasukazu Asano, Sumio Yamasaki

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    7 Citations (Scopus)

    Abstract

    A highly sensitive potentiometric flow injection determination of amylase activity was carried out, utilizing a redox reaction of hexacyanoferrate(III) in alkaline media with reducing sugar as product of the enzymatic hydrolysis reaction of starch with amylase. The analytical method is based on the potential change detection of a flow-through type redox electrode detector due to the composition change of a [Fe(CN)6]3--[Fe(CN)6]4- potential buffer solution, which is caused by the redox reaction with the product of the enzymatic reaction. A linear relationship exists between the potential change (peak height) and the activity of amylase. Amylase of a wide activity range from 2.5 x 10-2 to 1.2 x 10-4 U ml-1 can be determined by the changing the concentrations of the [Fe(CN)6]3--[Fe(CN)6]4- potential buffer from 10-3 to 10-5 M. The lower detection limit of amylase activity is 6.0 x 10-5 U ml-1. The sampling rate and relative standard deviation are 15 h-1 and 0.9% (n = 5) for 3.8 x 10-3 U ml-1 of amylase. The present method was successfully applied to determine amylase activity in real samples (commercial digestive medicines) with an accuracy of 4% compared with analytical results obtained using the present method with those achieved using the conventional titration method.

    Original languageEnglish
    Pages (from-to)565-573
    Number of pages9
    JournalTalanta
    Volume45
    Issue number3
    DOIs
    Publication statusPublished - Jan 1 1998

    All Science Journal Classification (ASJC) codes

    • Analytical Chemistry

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