Thermodynamic behaviour in capillary electrochromatography

Eindhoven University of Technology, Department of Chemical Engineering and Chemistry, Laboratory of Instrumental Analysis, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
Journal of Separation Science (Impact Factor: 2.74). 06/2002; 25(9):569 - 576. DOI: 10.1002/1615-9314(20020601)25:9<569::AID-JSSC569>3.0.CO;2-3


The thermodynamic behaviour of solutes was examined on four reversed-phase (RP) stationary phases under pressure-driven (viz. high performance liquid chromatography, HPLC) and electro-driven (viz. capillary electrochromatography, CEC) conditions. Thermodynamic constants such as standard enthalpy, entropy, and Gibbs free energy were compared for both separation modes. Differences and/or similarities observed were used as a tool in gaining a better understanding of the separation mechanism in CEC compared to HPLC. In addition, effects of temperature on the magnitude of electroosmotic flow (EOF) are explained in detail.

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