Multi-scan Voltammetric Determination of Carbohydrates Noble Metal Microelectrodes following Flow Injection and After Capillary Electrophoresis Separation

Two multi-scan techniques: cyclic voltammetry (CV) and fast Fourier transform squarewave voltammetry (FFT SWV) with Pt and Au microelectrodes were tested for the determination of five carbohydrates (lactose, sucrose, glucose, fructose and ribose) under FIA conditions. The best analytical results were obtained for the FFT SWV with a Pt microelectrode; in this case the detection limits were below 2X10-7 mol . dm-3 for all studied analytes. In addition, both methods were applied for end-capillary detection in capillary electrophoresis (CE) and tested during an analysis of a mixture of eight sugars. The advantages of scanning methods over constant potential (amperometric) detection methods are also discussed.