The effect of temperature and mobile phase composition on the adsorption isotherm of L-tryptophan using reversed phase HPLC

AEI 8

Tarab Ahmad, tahmad1@utk.edu, Department of Chemistry, University of Tennesse, 1420 Circle Dr. Buehler Hall 433, Knoxville, TN 37996 and Georges Guiochon, guiochon@novell.chem.utk.edu, Department of Chemistry, University of Tennessee, Knoxville, TN 37996-1600.
Single-component adsorption isotherms of tryptophan on a C18 bonded silica column were acquired by frontal analysis at five different temperatures and for mobile phases containing different concentrations of methanol or acetonitrile. The nature of the organic modifier affects the shape of the isotherm while its concentration and the temperature affect the numerical values of the isotherm coefficients. The model accounting best for all these isotherms and giving best agreement between the experimental and the calculated band profiles is the bi-Moreau model. This model is valid for all concentrations of acetonitrile or methanol in the mobile phase and at any temperature. This shows that there are significant molecular interactions between adsorbed molecules of tryptophan. The energy of these interactions depend on the experimental conditions.
 

Academic Employment Initiative
8:00 PM-10:00 PM, Monday, 11 September 2006 Moscone Center -- Hall D, Sci-Mix

Academic Employment Initiative

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006