On-line electrodialysis capillary zone electrophoresis mass spectrometry of inositol phosphates in complex matrices

Electrodialysis has been coupled to capillary zone electrophoresis-mass spectrometry for on-line clean-up and analyte concentration. Two different electrodialysis devices have been developed, each with its specific features. The first device consisting of a donor and an acceptor compartment, separated by a membrane with a cut-off of M-r 30 000, offers selectivity based on molecular mass, shape and charge. The second device consists of three compartments, separated by membranes with a cut-off of M-r 500 and 30 000, respectively. In addition to selectivity this device enables analyte enrichment between the two membranes. The developed methods have been applied to the determination of inositol phosphates in fermentation broth and in blood plasma. (C) 1997 Elsevier Science B.V.