Results 251 to 260 of about 36,758 (301)

Retention of β blockers on native titania stationary phase

Journal of Separation Science, 2011
AbstractIn recent years, metal oxides such as titania have been commercially available as chromatographic beds that can potentially be used to achieve novel separations of polar compounds. For example β blockers, which are more often encountered in environmental sciences, have a wide range of polarity, and their basic character leads to difficult ...
El Debs, Racha, Abi Jaoudé, Maguy, Morin, Nicolas, Miege, Cecile, Randon, Jérôme   +4 more
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Retention mechanisms on metallic stationary phases

Journal of Chromatography A, 1989
Abstract An electron-rich, porous graphitic carbon stationary phase for high-performance liquid chromatography has been shown to act as an electron-pair acceptor of solutes under non-polar conditions. The application of delocalized electron bands as chromatographic substrates was extended to other conductors, namely a palladium metal stationary phase,
Barbara J. Bassler, Romand Kaliszan, Richard A. Hartwick   +2 more
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Retention and selectivity of stationary phases for hydrophilic interaction chromatography

Journal of Chromatography A, 2011
More and more polar stationary phases have become available for the separation of small polar compounds in the past decade as hydrophilic interaction chromatography (HILIC) continues to find applications in new fields (e.g., metabolomics and proteomics). Bare silica phases remain popular, especially in the bio-analytical area.
Yong, Guo, Sheetal, Gaiki
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Retention characteristics of a new butylimidazolium-based stationary phase

Analytical and Bioanalytical Chemistry, 2005
A new HPLC stationary phase has been synthesized based on the ionic liquid n-butylimidazolium bromide. Imidazolium was covalently immobilized on a silica substrate through an n-alkyl tether and the retention characteristics of the resulting stationary phase were evaluated systematically.
Y, Sun, B, Cabovska, C E, Evans, T H, Ridgway, A M, Stalcup   +4 more
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HPLC retention behavior on hydride‐based stationary phases

Journal of Separation Science, 2007
AbstractTwo stationary phases attached to a silica hydride surface, cholesterol and bidentate C18, are investigated with a number of pharmaceutically related compounds in order to illustrate the various retention mechanisms that are possible for these bonded materials. The test solutes range from hydrophilic to hydrophobic based on log P (octanol/water
Joseph J, Pesek, Maria T, Matyska, Susan, Larrabee   +2 more
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Molecular mechanism of retention in reversed-phase high-performance liquid chromatography and classification of modern stationary phases by using quantitative structure–retention relationships

Journal of Chromatography A, 1999
Quantitative structure–retention relationships (QSRRs) were derived for logarithms of retention factors normalised to a hypothetical zero percent organic modifier eluent, log kw, determined on 18 reversed-phase high-performance liquid chromatography (RP ...
Roman Kaliszan, Michał J Markuszewski, Carel A Cramers   +2 more
exaly   +2 more sources

Correlation of Kováts Retention Indices on Polar Stationary Phase with That on Non-polar Stationary Phase

Analytical Letters, 1997
Abstract A retention equation, , was developed to correlate the Kovats retention indices on polar stationary phases with that on non-polar stationary phases. Some differences of interaction forces of solutes on polar and non-polar stationary phases were taken into account.
Wenling Wang, Xiangmin Zhang*, Jiaqi Deng, Peichang Lu   +3 more
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Temperature effects on solute retention for hydride‐based stationary phases

Journal of Separation Science, 2007
AbstractThe effect of solute retention is investigated for two hydride‐based stationary phases: bidentate C18 and cholesterol. Several small molecules and peptides are used as solutes. In the reversed‐phase mode, most compounds have the expected temperature behavior, i. e. decreasing retention with increasing temperature.
Joseph J, Pesek, Maria T, Matyska, Milton T W, Hearn, Reinhard, Boysen   +3 more
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Thermodynamic and QSRR Modeling of HPLC Retention on Modern Stationary Phases

Journal of Liquid Chromatography & Related Technologies, 2014
This paper investigates correlations between the standard chromatographic parameter, log kw, obtained experimentally (classical thermodynamic) and obtained through the use of quantitative structure-retention relationships (QSRR) models (extrathermodynamic approach).
Mateusz Kaczmarek, Adam Buciński, Michał P. Marszałł, Anna Badura, Roman Kaliszan   +4 more
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Retention of Ions on Nonporous Charged Stationary Phases

Analytical Chemistry, 2000
The interactions between ion-exchange resins and counterions consist of several mechanisms, such as ion-pair formation between active sites and counterions, specific adsorption, solvation changes, and double-layer accumulation. The double-layer accumulation of ions, which is a typical nonstoichiometric mechanism, is an important factor governing ...
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