Determination of carbohydrates by capillary zone electrophoresis with amperometric detection at a nano-nickel oxide modified carbon paste electrode

In this paper, a nano-NiO modified carbon paste electrode in capillary zone electrophoresis with amperometric detection (CZE-AD) was firstly applied to the determination of carbohydrates. Effects of several important factors such as detection potential, the concentration of running buffer, separation voltage and injection time were investigated to acquire the optimum conditions. Under the selected optimum conditions, three carbohydrates: glucose, sucrose and fructose could be perfectly separated within 20 min. The relationships between peak current and concentration of three carbohydrates were linear over about 3 orders of magnitude with detection limits (S/N = 3) ranging from 3.0 x 10(-7) to 6.0 x 10(-7) mol L-1. The electrode was stable, and can be used for at least one week. The proposed method has been successfully applied to monitor carbohydrates in the real samples with satisfactory assay results. (c) 2007 Elsevier Ltd. All rights reserved.