Selectivity differences between alkyl and polar-modified alkyl phases in reversed phase high performance liquid
Lin-Lin Jing1, Ru Jiang, Peng Liu
1Department of Chemistry, Fourth Military Medical University, Xi'an, Shaanxi, China.
Journal of Separation Science
|December 25, 2008
Summary
Polar-modified reversed-phase (RP) chromatography columns offer distinct advantages over conventional C18 phases. These new phases exhibit reduced hydrophobicity and silanol activity, improving peak shapes for diverse analytes.
Area of Science:
- Analytical Chemistry
- Chromatography
- Separation Science
Background:
- Conventional C18 phases are widely used in reversed-phase (RP) chromatography.
- Polar-modified phases offer alternative selectivity and properties compared to standard alkyl phases.
- Understanding the behavior of novel stationary phases is crucial for method development.
Purpose of the Study:
- To synthesize and evaluate novel ODS and polar-modified RP stationary phases.
- To compare the chromatographic behavior and selectivity of polar-modified phases versus conventional C18 phases.
- To assess the stability and peak shape performance of the new phases.
Main Methods:
- Synthesis of ODS and polar-modified alkyl stationary phases.
- Evaluation of column stability under acidic (pH 1.5) and basic (pH 10) conditions.
- Chromatographic analysis of neutral analytes, nucleotides, and tricyclic antidepressants.
Main Results:
- Polar-modified phases demonstrated satisfactory stability across a wide pH range.
- Excellent peak shapes were observed for most compounds on polar-modified alkyl phases.
- These phases exhibited significantly reduced hydrophobic nature and silanol activity compared to C18.
Conclusions:
- Polar-modified RP phases offer improved performance and selectivity over conventional C18.
- The reduced hydrophobicity and silanol activity enhance peak shape and separation capabilities.
- These novel phases are suitable for challenging separations, including nucleotides and antidepressants.
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