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Our work addresses physicochemical aspects of separations, with emphasis on
issues affecting efficiency and peak capacity. Experimental studies are
accompanied by theory that explains the results. Theory also is developed to
explain the results of other researchers. Much effort has been directed at
understanding dispersion or band broadening in micellar electro kinetic
chromatography (MEKC). In general, variations of efficiency at low
electric-field strengths are explained well by longitudinal diffusion, and
losses of efficiency at high field strength due to Joule heating have been
quantified. Other high-field dispersions, e.g., adsorption and micellar
polydispersity, are currently under study. The asymmetry of peaks of neutral
analytes in MEKC has been shown to result largely from a nonlinear
chromatographic isotherm, but electrophoretic dispersions also are important
and merit study. Simple ways to model the efficiency of such peaks are being
developed. Improvements are being sought to existing theory describing the
effects of preconcentration on efficiency in MEKC. In other work, probabability
theory is used to model the completeness of separation of complex mixtures.
Recent efforts have addressed column-switching gas chromatography, and current
efforts are directed toward two-dimensional gas chromatography.
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Williamson, Y.; Davis, J.M. “Origin of Peak Asymmetry and Isotherm Nonlinearity in Micellar Electrokinetic Chromatography: Variation of Peak Shape with Buffer Concentration”, Electrophoresis 2006, 27, 572-583.
Williamson, Y.; Davis, J.M. “Modeling of Anti-Langmuirian Peaks in Micellar Electrokinetic Chromatography: Benzene and Naphthalene”, Electrophoresis 2005, 26, 4026-4042.
Davis, J.M.; Blumberg, L.M. “Probability Theory for Number of Mixture Components Resolved by n Independent Columns”, J. Chromatogr. A 2005, 1096, 28-39.
Liu, S.; Davis, J.M. “Verification of Statistical-Overlap Theory in Micellar Electrokinetic Chromatography”, Anal. Bioanal. Chem. 2005, 382, 765-776.
Davis, J.M. "Statistical-Overlap Theory for Elliptical Zones of High Aspect Ratio in Comprehensive Two-Dimensional Separations”, J. Sep. Sci., 2005, 28, 347-359.
Pompe, M.; Davis, J.M.; Samuel, C.D. "Prediction of Thermodynamic Parameters in Gas Chromatography from Molecular Structure: Hydrocarbons", J. Chem. Inform. Comp. Sci., 2004, 44, 399-409.
Davis, J.M. "Assessment by Monte Carlo Simulation of Thermodynamic Correlation of Retention Times in Dual-Column Temperature Programmed Comprehensive Two-Dimensional Gas Chromatography", ", J. Sep. Sci. 2004, 27, 417-430.
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