Determination of carbohydrates by capillary electrophoresis with electrospray-mass spectrometric detection

A method for the determination of underivatized carbohydrates using capilla ry electrophoresis (CE) with detection by electrospray ionization-mass spec trometry (ESI-MS) presented. Highly alkaline carrier electrolytes based on volatile organic bases like is diethylamine (DEA) combined with MS detectio n in the negativ-ion mode proved to be the optimum solution for the separat ion and detection of these analytes. Optimization of the carrier electrolyt e composition has been performed with respect to its pH, ionic strength as well as the addition of an organic modifier. The influence of the DEA conce ntration in the sheath liquid on parameters like peak shapes or signal-to-n oise (S/N) ratios was also investigated. Limits of detection (LOD) were in the range of 0.5-3.0 mgL(-1) and calibration was linear over an order of ma gnitude for almost all solutes investigated. Finally, the applicability of this method for the analysis of real samples was demonstrated with wine sam ples.