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| Content Provider | World Health Organization (WHO)-Global Index Medicus |
|---|---|
| Author | Dolan, J. W. Kirkland, J. J. Dorsey, J. G. Snyder, L. R. Carr, P. W. |
| Description | Country affiliation: United States Author Affiliation: Carr PW ( University of Minnesota, Minneapolis, MN, USA.); Dolan JW ( LC Resources, Lafayette, CA, USA. Electronic address: John.Dolan@LCResources.com.); Dorsey JG ( Florida State University, Tallahassee, FL, USA.); Snyder LR ( LC Resources, Lafayette, CA, USA.); Kirkland JJ ( Advanced Materials Technologies, Wilmington, DE, USA.) |
| Abstract | Column selectivity in reversed-phase chromatography (RPC) can be described in terms of the hydrophobic-subtraction model, which recognizes five solute-column interactions that together determine solute retention and column selectivity: hydrophobic, steric, hydrogen bonding of an acceptor solute (i.e., a hydrogen-bond base) by a stationary-phase donor group (i.e., a silanol), hydrogen bonding of a donor solute (e.g., a carboxylic acid) by a stationary-phase acceptor group, and ionic. Of these five interactions, hydrogen bonding between donor solutes (acids) and stationary-phase acceptor groups is the least well understood; the present study aims at resolving this uncertainty, so far as possible. Previous work suggests that there are three distinct stationary-phase sites for hydrogen-bond interaction with carboxylic acids, which we will refer to as column basicity I, II, and III. All RPC columns exhibit a selective retention of carboxylic acids (column basicity I) in varying degree. This now appears to involve an interaction of the solute with a pair of vicinal silanols in the stationary phase. For some type-A columns, an additional basic site (column basicity II) is similar to that for column basicity I in primarily affecting the retention of carboxylic acids. The latter site appears to be associated with metal contamination of the silica. Finally, for embedded-polar-group (EPG) columns, the polar group can serve as a proton acceptor (column basicity III) for acids, phenols, and other donor solutes. |
| ISSN | 00219673 |
| Volume Number | 1395 |
| e-ISSN | 18733778 |
| Journal | Journal of Chromatography A |
| Language | English |
| Publisher | Elsevier |
| Publisher Date | 2015-05-22 |
| Publisher Place | Netherlands |
| Access Restriction | One Nation One Subscription (ONOS) |
| Subject Keyword | Chromatography, Reverse-phase Methods Standards Carboxylic Acids Chemistry Hydrogen Bonding Hydrogen-ion Concentration Hydrophobic And Hydrophilic Interactions Metals Silicon Dioxide Journal Article Discipline Analytical Chemistry |
| Content Type | Text |
| Resource Type | Article |
| Subject | Organic Chemistry Medicine Analytical Chemistry Biochemistry |
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