Characterization of quartz capillaries for capillary electrophoresis

Kohr, Jörg; Engelhardt, H.

doi:10.1016/0021-9673(93)83248-q

Cited by 53 publications

(26 citation statements)

References 26 publications

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“…In order to determine the polar and nonpolar surface activity, the coated capillaries were characterized with GC. This procedure has already been published for vinylsilanized quartz capillaries by Kohr and Engelhardt [35].…”

Section: Gc Experiments For Surface Characterizationmentioning

confidence: 97%

Control of electroosmotic flow in nonaqueous capillary electrophoresis by polymer capillary coatings

Steiner

Hassel

2003

Electrophoresis

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In aqueous capillary electrophoresis the electroosmotic flow (EOF) can be strongly suppressed or eliminated by coating the capillary surface silanols either by buffer additive adsorption or chemical modification. Hydrophilic coatings, e.g., polyvinyl alcohol (PVA) proved to be most efficient for EOF control in applications like DNA analysis. In nonaqueous capillary electrophoresis (NACE), however, the EOF cannot be totally suppressed with these capillaries and coating efficiency turned out to be solvent-depending. In this paper, fused-silica capillaries with monomeric and polymeric coatings differing in hydrophobicity and chemical properties (vinyl, vinyl acetate, vinyl alcohol and acrylates with different alkyl chain length) were investigated. Besides studying the EOF characteristics with different organic solvents and water, gas chromatography (GC) measurements were carried out to probe the silanol reduction via ether retention and the surface hydrophobicity by retention of nonane. Good correlations between GC results and EOF magnitude could be found. It could be demonstrated that the polymeric coating has to be solvatized by the buffer solvent to reduce the EOF. The PVA coating was optimal for aqueous systems but not effective for some nonaqueous buffers. On the other hand, polyvinyl acetate and polyethyl acrylate as polymeric coatings proved to be optimal to reduce the EOF in NACE.

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Section: Gc Experiments For Surface Characterizationmentioning

confidence: 97%

Control of electroosmotic flow in nonaqueous capillary electrophoresis by polymer capillary coatings

Steiner

Hassel

2003

Electrophoresis

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“…Characterization of the properties of coated capillaries is commonly performed to measure the EOF and investigate its dependence on the pH of the buffer [7]. Measurement of the residual EOF in the coated capillary can be obtained by photometric monitoring of the electrophoretic pattern of a neutral marker.…”

Section: Characterization Of a Capillary Coatingmentioning

confidence: 99%

Polymer wall coatings for capillary electrophoresis

Horváth¹,

Dolnı́k²

2001

Electrophoresis

452

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This review article describes the preparation of dynamic and static polymeric wall coatings for capillary electrophoresis. Properties of bare fused-silica surfaces and methods for the characterization of capillary coatings are summarized. The preparation and basic properties of neutral and charged wall coatings are considered. Finally, advantages and potential applications of various coatings are discussed.

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“…Significant differences in EOF level between capillaries from different suppliers [7] or different capillary batches [7][8][9] are frequently reported, which can be explained by surface cracks, but also surface contamination [10]. The fluctuation of the number of active silanol groups is particularly crucial in a pH range of 4-7 (see [6] and references therein).…”

Section: Introductionmentioning

confidence: 97%

Influence of polyelectrolyte coating conditions on capillary coating stability and separation efficiency in capillary electrophoresis

et al. 2008

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Polyelectrolytes are widely used in capillary electrophoresis as coating agents of silica capillaries to prevent adsorption phenomena and improve the repeatability of peptide and protein analysis. A systematic study of the coating experimental conditions has been carried out to optimize coating stability and performance. The main experimental parameters studied were the type and concentration of polyelectrolytes used in several monolayer and multilayer coatings, the ionic strength of coating and stabilizing solutions, and the procedures used for coating and capillary storage. Electroosmotic flow magnitude, direction and repeatability were used to monitor coating stability. Coating ability to limit adsorption was investigated by monitoring variations of migration times, time-corrected peak areas and separation efficiency of test peptides. Capillary-to-capillary and batch-to-batch reproducibility was also studied. In addition, the separation performance of polyelectrolyte coatings were compared to those obtained with bare silica capillaries.

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Characterization of quartz capillaries for capillary electrophoresis

Cited by 53 publications

References 26 publications

Control of electroosmotic flow in nonaqueous capillary electrophoresis by polymer capillary coatings

Control of electroosmotic flow in nonaqueous capillary electrophoresis by polymer capillary coatings

Polymer wall coatings for capillary electrophoresis

Influence of polyelectrolyte coating conditions on capillary coating stability and separation efficiency in capillary electrophoresis

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