Experimental verification and thermodynamic study of the reversal of elution order in chromatography

UNCW Author/Contributor (non-UNCW co-authors, if there are any, appear on document)
Jonna B. Clark (Creator)
The University of North Carolina Wilmington (UNCW )
Web Site: http://library.uncw.edu/
Dean Shirazi

Abstract: The demand for high purity compounds in the pharmaceutical industry has led to a greater interest in purification techniques. Preparative chromatography has become a useful purification technique due to its broad range of applications. Preparative scale separations employ a high concentration of analytes which can affect both peak shape and separation of the components. Peak shape is dependant upon the adsorption isotherm of the component, which is linear at the analytical scale and nonlinear at the preparative scale. Knowledge of the adsorption characteristics of the components over a wide concentration range could lead to more efficient separation methods. Due to the peak shape of components in nonlinear chromatography, reversal of elution order of the major and minor peaks is preferred in some cases. In this research, a chiral compound was studied to determine if a reversal of elution order could be observed by changing the chromatographic conditions. A non-chiral compound, diclofenac, and one of its process impurities, 2-chloro-N-(2,6-dichlorophenyl)-N-phenylacetamide (hereinafter referred to as “2- chloro”), was also studied to see if a reversal in elution order could be observed by changing the chromatographic conditions. The adsorption isotherms for this diclofenac and 2-chloro were measured and fitted to isotherm models. A possible mechanism to explain the retention behavior for these compounds is also discussed.

Additional Information

A Thesis Submitted to the University of North Carolina at Wilmington in Partial Fulfillment of the Requirement for the Degree of Masters of Science
Language: English
Date: 2009
Thesis (Chemistry and Biochemistry)
Thesis (Chemistry and Biochemistry)

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