Nickel oxide-modified composite electrode for electrochemical detection of polyhydroxyl compounds in liquid chromatographic analysis

Nickel oxide-modified polymeric composite electrode was prepared for electrochemical detection in liquid chromatography (LC-ECD) or flow injection analysis of polyhydroxyl compounds. The composite electrode was prepared by incorporating semigraphitic carbon black and nickel oxide particles in polystyrene polymer matrix cross-linked with divinylbenzene. The analytical characteristics of the electrodes in LC-ECD and flow injection analysis of polyhydroxyl compounds were evaluated in terms of sensitivity, reproducibility, stability and surface renewability. The electrode revealed three-four orders of dynamic concentration ranges from sub-micromolar to 10(-3) M with high correlation coefficients from 0.9998 to 0.9999 for various polyhydroxyl compounds. The standard deviation for the surface restoration was <2%. High reproducibility, stability, and the renewability of surface are thought to be due to the catalyst particles highly dispersed through robust polymeric electrode matrix. (C) 2002 Elsevier Science B.V. All rights reserved.