Three-compartment electrodialysis device for on-line sample cleanup and enrichment prior to capillary electrophoresis

An electrodialysis device for on-line coupling to capillary electrophoresis has been developed. The device consists of three compartments that are separated by two membranes with M-r cut-off values of 500 and 30 000, respectively. The selectivity of the method is based on charge, molecular mass and shape. A concentration factor of 40-50 has been achieved. Sample clean-up and analyte enrichment take only ca. 5 min. Optimization and characterization of the device have been performed and electrodialysis has been applied to the analysis of an inositol trisphosphate derivative in a complex matrix. (C) 1997 Elsevier Science B.V.