Column selectivity in reversed-phase liquid chromatography. VI. Columns with embedded or end-capping polar groups.
A previous model of column selectivity for reversed-phase liquid chromatography (RP-LC) has been applied to an additional 21 columns with embedded or end-capping polar groups (EPGs). Embedded-polar-group columns exhibit a significantly different selectivity vs. non-EPG, type-B columns, generally showing preferential retention of hydrogen-bond donors, as well as decreased retention for hydrogen-bond acceptors or ionized bases. EPG-columns are also generally less hydrophobic (more polar) than are non-EPG-columns. Interestingly, columns with polar end-capping tend to more closely resemble non-EPG columns, suggesting that the polar group has less effect on column selectivity when used to end-cap the column versus the case of an embedded polar group. Column selectivity data reported here for EPG-columns can be combined with previously reported values for non-EPG columns to provide a database of 154 different columns. This enables a comparison of any two of these columns in terms of selectivity. However, comparisons that involve EPG columns are more approximate.
Wilson
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BASi Northwest Laboratory, 3138 NE Rivergate, Bldg. 301C, McMinnville, OR 97128, USA.
Gilroy
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Dolan
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Snyder
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D000143:Acids / Q000737:chemistry; D002853:Chromatography, Liquid / Q000295:instrumentation* / Q000379:methods; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D012680:Sensitivity and Specificity; D012995:Solubility; D055672:Static Electricity
D000143:Acids