PubAg

Main content area

Peptide pore accessibility in reversed-phase chromatography

Author:
Gétaz, David, Ströhlein, Guido, Morbidelli, Massimo
Source:
Journal of chromatography 2009 v.1216 no.6 pp. 933-940
ISSN:
0021-9673
Subject:
acetonitrile, chromatography, ionic strength, models, porosity, sorption isotherms
Abstract:
The effect of salt or peptide concentration on peptide porosity (i.e. the porosity accessible to a given peptide) is investigated on six different reversed-phase stationary phases. The peptide porosity is found to increase with the local concentration of negative charges following a saturation-type function within the same porosity boundaries for both cases. This can induce the formation of anti-Langmuirian peaks in non-adsorbing conditions since the local increase of the ionic strength due to the peptide concentration increases the porosity accessible to the peptide. This behavior can be well reproduced by the ideal model of chromatography assuming non-constant porosity. The acetonitrile adsorption isotherm was also measured on all the considered reversed-phase stationary phases. A comparison between the stationary phases shows a correlation between the amount of acetonitrile accumulated in the pores and the reduced pore accessibility for the peptide.
Agid:
278203