Stabilization of reversed phases for liquid chromatography

Sagliano, Nicholas; Hartwick, Richard A.; Patterson, R.E.; Woods, Bruce A.; Bass, J.L.; Miller, Neil T.

doi:10.1016/s0021-9673(00)90567-3

Cited by 17 publications

(5 citation statements)

References 25 publications

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“…Different degradation rates were found for several commercial C18 columns and certain silica-based C18 packings were reported to be used for long periods of time at pH 9, without significant changes in retention properties [119]. Under acidic conditions, a high rate of bonding provides a better phase stability and long alkyl chains are preferred to short ones [120,123]. This has been subsequently confinned by other studies.…”

Section: Stability Of Bonded Phasesmentioning

confidence: 96%

Silica and other materials as supports in liquid chromatography. Chromatographic tests and their importance for evaluating these supports. Part I

et al. 2001

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Reversed-phase liquid chromatography (RP-HPLC) has become a powerful and widely employed technique in the separation and analysis of a great variety of compounds with different functionalities. The most common type of stationary phase for RP-HPLC consists of nonpolar, hydrophobic organic species (e.g., octyl, octadecyl) attached by siloxane bonds to the surface of a silica support. In the first part of this article, a description of the many beneficial properties that make porous silica the most employed support in RP-HPLC will be presented, starting from the synthesis of silica. It is noteworthy that the chromatographic properties of the final column are strictly correlated to the preparation type. A silica surface possesses a number of attractive properties, but also some drawbacks. Unreacted or residual silanols interact with basic compounds and can induced peak tailing, which means a loss in chromatographic performance. This problem has lead many manufactures to produce stationary phases with reduced silanol activity which improve dramatically the peak shape of basic compounds. In the second part of this review, different approaches are proposed to obtain less reactive stationary phases

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Section: Stability Of Bonded Phasesmentioning

confidence: 96%

Silica and other materials as supports in liquid chromatography. Chromatographic tests and their importance for evaluating these supports. Part I

et al. 2001

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“…Although these changes can be determined, the factors causing the process of stationary phase degradation are not completely clear. The influence of ligands anchored a t the silica surface, their functionality, chain length, and surface concentration on the process of hydrolysis, has been partially reported previously (3, [15][16][17][18][19]. However, the specific effect of the ligand alkyl chain length of chemically bonded phases on stability and ligand and/or substrate hydrolysis and dissolution has not yet been systematically studied.…”

Section: Introductionmentioning

confidence: 99%

Influence of alkyl chain length on the stability of n-alkyl-modified reversed phases. 1. Chromatographic and physical analysis

Hetem¹,

Haan²,

Claessens³

et al. 1990

Anal. Chem.

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Document VersionPublisher's PDF, also known as Version of Record (includes final page, issue and volume numbers) Please check the document version of this publication:• A submitted manuscript is the author's version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website.• The final author version and the galley proof are versions of the publication after peer review.• The final published version features the final layout of the paper including the volume, issue and page numbers. General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. Link to publication• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal ? Take down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Several factor$ affecting long-term stability of modern reversed-phase htgh-performance llquld chromatography (RP-HPLC) phases are consldered and their lndlvldual contrlbutlons are evaluated In this paper and the following paper In this Issue. Tho stationary phases under study were Identically modifled on the same batch of slllca substrate to ellmlnate dmerences In substrate properties and synthesis conditions. Modtflcatlons with llgand alkyl chain length between C1 and C18 were performed such that an approxknately equal llgand density was obtained for the seven RP-HPLC phases studled. These n-alkyldimethyldloxydlane bonded phases were exposed to sknulated aglng experlments. A subsequent chromatographk characterlzatlon regarding changes In capacity, llp6phlUc and polar sdectlvlty, and slllca degradatlon related separation performance was carried out.

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“…Liquid chromatography is one of the most widely used separation techniques, yet there are still many questions concerning the organization and dynamics of the stationary phase structure. Various spectroscopic techniques have been used to characterize these phases including NMR, − Fourier transform infrared (FTIR), − Raman, X-ray photoelectron spectroscopy (XPS), , and fluorescence − measurements. An additional method that has proved useful in probing chromatographic monolayers is fluorescence recovery after photobleaching. − This method measures transport rate of a probe molecule over distances greater than micrometers.…”

Section: Introductionmentioning

confidence: 99%

Lateral Diffusion of an Adsorbate at Chromatographic Octadecylsiloxane/Water Interfaces of Varying Hydrocarbon Density

Kovaleski

Wirth

1997

J. Phys. Chem. B

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The lateral diffusion of acridine orange was investigated at the interface of water and octadecylsiloxane (C18) monolayers of varying hydrocarbon density. The surfaces examined ranged from 24% to 100% of a sterically complete monolayer of 3.5 μmol/m2 in alkane coverage. Fluorescence recovery after photobleaching was used to measure the lateral diffusion coefficient. Acridine orange is a fluorophor known to reside at the water/hydrocarbon interface, negligibly adsorbing to bare silica. Its diffusion coefficient was found to decrease 500-fold as the surface coverage was reduced 4-fold. By use of effective medium and percolation theory, the strong density dependence was attributed to decreased contiguity of hydrocarbon at lower coverages. The temperature dependence of the lateral diffusion coefficient showed that the decease in diffusion rate at lower coverage was entirely due to an increase in the entropic barrier, pointing to percolation as the mechanism of diffusion.

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Stabilization of reversed phases for liquid chromatography

Cited by 17 publications

References 25 publications

Silica and other materials as supports in liquid chromatography. Chromatographic tests and their importance for evaluating these supports. Part I

Silica and other materials as supports in liquid chromatography. Chromatographic tests and their importance for evaluating these supports. Part I

Influence of alkyl chain length on the stability of n-alkyl-modified reversed phases. 1. Chromatographic and physical analysis

Lateral Diffusion of an Adsorbate at Chromatographic Octadecylsiloxane/Water Interfaces of Varying Hydrocarbon Density

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