Analytical Sciences

Abstract − Analytical Sciences, 14(1), 71 (1998).

Stripping Voltammetric Determination of Choline Based onMicro-Fabricated Composite Membrane
Hye Jin LEE, Carine BERIET and Hubert H. GIRAULT*
Laboratoire d'Electrochimie,Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne,Switzerland
A novel stripping voltammetric method for the determination of non-redox ionic species is presented. Using choline ion(Ch + ) as an example, wedemonstrate how a micro machined PVC-NPOE gel membrane can be used toaccumulate Ch +ion under potentiostatic steady-state conditions. Theamperometric stripping of the target ion can be carried out by anyvoltammetric method but we presently illustrate the principle using linearsweep voltammetry. The effect ofaccumulation time, accumulation potential and choline ion concentration hasbeen examined. The present work alsoincludes the quantitative study of an enzyme reaction generating choline,namely the reaction of calcium phosphocholinewith alkaline phosphatase. With this experimental approach, mg ml-1 concentration level of alkalinephosphatase enzymecan be determined. (Keywords: Excimer laser, choline, ion transfer, polymer membrane,stripping voltammetry, alkaline phosphatase)