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Title: A chromatographic estimate of the degree of surface heterogeneity of RPLC packing materials. III. Endcapped amido-embedded reversed phase

Abstract

The difference in adsorption behavior between a conventional monomeric endcapped C{sub 18} stationary phase (3.43 {micro}mol/m{sup 2}) and an endcapped polymeric RP-Amide phase (3.31 {micro}mol/m{sup 2}) was investigated. The adsorption isotherms of four compounds (phenol, caffeine, sodium 2-naphthalene sulfonate, and propranololium chloride) were measured by frontal analysis (FA) and the degree of heterogeneity of each phase for each solute was characterized by their adsorption energy distributions (AED), derived using the Expectation-Maximization method. The results show that only certain analytes (phenol and 2-naphthalene sulfonate) are sensitive to the presence of the polar embedded amide groups within the RP phase. Their binding constants on the amide-bonded phase are significantly higher than on conventional RPLC phases. Furthermore, an additional type of adsorption sites was observed for these two compounds. However, these sites having a low density, their presence does not affect much the retention factors of the two analytes. On the other hand, the adsorption behavior of the other two analytes (caffeine and propranololium chloride) is almost unaffected by the presence of the amide group in the bonded layer. Strong selective interactions may explain these observations. For example, hydrogen-bond interactions between an analyte (e.g., phenol or naphthalene sulfonate) and the carbonyl group (acceptor)more » or the nitrogen (donor) of the amido-embedded group may take place. No such interactions may take place with either caffeine or the cation propranololium chloride. This study confirms the hypothesis that analytes have ready access to locations deep inside the bonded layer, where the amide groups are present.« less

Authors:
 [1];  [2]
  1. University of Tennessee, Knoxville (UTK)
  2. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
989608
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chromatography A; Journal Volume: 1103; Journal Issue: 2006
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; LIQUID COLUMN CHROMATOGRAPHY; EXTRACTION COLUMNS; COLUMN PACKING; PERFORMANCE; ADSORPTION ISOTHERMS; CAFFEINE; SULFONATES; NAPHTHALENE; PHENOL; ORGANIC CHLORINE COMPOUNDS; ENERGY SPECTRA; AMIDES; SORPTIVE PROPERTIES

Citation Formats

Gritti, Fabrice, and Guiochon, Georges A. A chromatographic estimate of the degree of surface heterogeneity of RPLC packing materials. III. Endcapped amido-embedded reversed phase. United States: N. p., 2006. Web. doi:10.1016/j.chroma.2005.11.089.
Gritti, Fabrice, & Guiochon, Georges A. A chromatographic estimate of the degree of surface heterogeneity of RPLC packing materials. III. Endcapped amido-embedded reversed phase. United States. doi:10.1016/j.chroma.2005.11.089.
Gritti, Fabrice, and Guiochon, Georges A. Sun . "A chromatographic estimate of the degree of surface heterogeneity of RPLC packing materials. III. Endcapped amido-embedded reversed phase". United States. doi:10.1016/j.chroma.2005.11.089.
@article{osti_989608,
title = {A chromatographic estimate of the degree of surface heterogeneity of RPLC packing materials. III. Endcapped amido-embedded reversed phase},
author = {Gritti, Fabrice and Guiochon, Georges A},
abstractNote = {The difference in adsorption behavior between a conventional monomeric endcapped C{sub 18} stationary phase (3.43 {micro}mol/m{sup 2}) and an endcapped polymeric RP-Amide phase (3.31 {micro}mol/m{sup 2}) was investigated. The adsorption isotherms of four compounds (phenol, caffeine, sodium 2-naphthalene sulfonate, and propranololium chloride) were measured by frontal analysis (FA) and the degree of heterogeneity of each phase for each solute was characterized by their adsorption energy distributions (AED), derived using the Expectation-Maximization method. The results show that only certain analytes (phenol and 2-naphthalene sulfonate) are sensitive to the presence of the polar embedded amide groups within the RP phase. Their binding constants on the amide-bonded phase are significantly higher than on conventional RPLC phases. Furthermore, an additional type of adsorption sites was observed for these two compounds. However, these sites having a low density, their presence does not affect much the retention factors of the two analytes. On the other hand, the adsorption behavior of the other two analytes (caffeine and propranololium chloride) is almost unaffected by the presence of the amide group in the bonded layer. Strong selective interactions may explain these observations. For example, hydrogen-bond interactions between an analyte (e.g., phenol or naphthalene sulfonate) and the carbonyl group (acceptor) or the nitrogen (donor) of the amido-embedded group may take place. No such interactions may take place with either caffeine or the cation propranololium chloride. This study confirms the hypothesis that analytes have ready access to locations deep inside the bonded layer, where the amide groups are present.},
doi = {10.1016/j.chroma.2005.11.089},
journal = {Journal of Chromatography A},
number = 2006,
volume = 1103,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}