Application of open tubular electrochromatography for acidic and basic analytes

Dube, Simiso; Smith, Roger M.

doi:10.1007/bf02492545

Cited by 7 publications

(7 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Another way to increase the phase ratio, the surface area, and the loading capacity of a capillary is by use of porouslayer open-tubular columns [2,[149][150][151][152]. Huang et al [2] introduced the utility of such columns with a positively charged hydrocarbonaceous porous layer as the stationary phase for the separation of basic proteins and peptides.…”

Section: Porous Layersmentioning

confidence: 99%

“…The separation of charged analytes was also examined on porous-layer open-tubular capillaries [152]. The preparation of the stationary phase was performed by use of the sol-gel technique.…”

Section: Porous Layersmentioning

confidence: 99%

“…In order to circumvent these drawbacks, the sol-gel technique was introduced for the synthesis of organicinorganic hybrid materials that are used as stationary phases in OT-CEC. Recently, the sol-gel technique, which combines the synthesis of a bonded phase and a supporting porous silica film in a single step, has gained much attention [18,29,151,152,[163][164][165][166][167][168][169][170].…”

Section: Sol-gel Techniquementioning

confidence: 99%

See 2 more Smart Citations

Analytical separations in open‐tubular capillary electrochromatography

Kapnissi‐Christodoulou

Zhu

Warner

2003

Electrophoresis

View full text Add to dashboard Cite

This review represents a summary of recent progress in open-tubular capillary electrochromatography (OT-CEC) for chiral and achiral separations. The OT-CEC approach is an alternative to packed-CEC that could eliminate the problems associated with retaining frits and silica particles. In OT-CEC, the stationary phase is immobilized on the inner walls of the capillary. Preparation of the stationary phase is critical for OT-CEC. The preparation methods for capillary columns include (i) adsorption, (ii) covalent bonding and/or cross-linking, (iii) porous layers, (iv) chemical bonding after etching, (v) sol-gel, and (vi) molecular imprinting. Major developments, potential applications, technical difficulties and advantages associated with these wall coatings in OT-CEC are presented. In addition, the coupling of OT-CEC with mass spectrometry (MS) is briefly reviewed. Several applications of this hyphenated technique for analytical separations are also summarized.

show abstract

Section: Porous Layersmentioning

confidence: 99%

“…The separation of charged analytes was also examined on porous-layer open-tubular capillaries [152]. The preparation of the stationary phase was performed by use of the sol-gel technique.…”

Section: Porous Layersmentioning

confidence: 99%

Section: Sol-gel Techniquementioning

confidence: 99%

See 1 more Smart Citation

Analytical separations in open‐tubular capillary electrochromatography

Kapnissi‐Christodoulou

Zhu

Warner

2003

Electrophoresis

View full text Add to dashboard Cite

show abstract

“…To overcome the intrinsic drawback, a larger amount of functional ligands are attached onto the etched capillaries or porous polymeric ones by physical adsorption or chemical bonding, but both approaches still have their advantages and disadvantages [3][4][5]. An alternative method is given to coat an interest polymer, which is loading with high ligand capacity and free of unneeded adsorption, directly onto the treated silica wall.…”

Section: Introductionmentioning

confidence: 99%

Metallomesogenic stationary phase for open‐tubular capillary electrochromatography

Chen

2006

Electrophoresis

View full text Add to dashboard Cite

A synthetic coppermesogenic polymer is prepared and then covalently bonded to the siloxane-based deactivated column as the stationary phases of open-tubular CEC with essentially high phase ratio. The EOF generated from the modified phase is surveyed through conventional aqueous buffers and hydroorganic mobile phases. Zeta potentials, which are computed from the EOF data and the ratio of dielectric constant to viscosity, are plotted as a function of pH, ionic molarity, and compositional range. These plots responsible for the electroosmotic characteristic of the bonded phases are found to be like those of bare fused-silica or deactivated columns through decreasing or increasing the ACN content in the mobile phase, respectively. This two-phase characteristic is basically derived from the polymeric configuration with carboxylato ligands attached onto the polysiloxane backbone. Phthalates and amino acids are suitable probes to examine the two phenomena, more-polar and less-polar mediums, respectively, and to judge whether the chromatographic retention is the major source of separation mechanism. With the mixing modes of Lewis acid-base interaction, dispersive force, and shape discrimination, the chromatographic partition adequately accomplishes the uneasily resolved separations by only CZE mode, although the electrophoretic migration is truly somewhat involved.

show abstract

“…Conventional RP‐CEC is rarely used for the separation of basic compounds, since the interaction between the basic compounds and the residual silanol groups of the stationary phase usually results in the peak tailing . The use of a mixed‐mode capillary allows the separation of basic compounds under counter‐EOF conditions, and some basic compounds were selected as the model compounds for evaluating the mixed‐mode capillary.…”

Section: Resultsmentioning

confidence: 99%

Open tubular columns with mixed‐mode reversed‐phase and weak anion‐exchange stationary phase for capillary electrochromatography

Lei

Zhang

2013

J of Separation Science

View full text Add to dashboard Cite

Columns for open tubular capillary electrochromatography, coated with a mixed-mode (RP/ion-exchange) stationary phase, were prepared by using the sol-gel method. The synthetic procedure was optimized by changing the ratios of tetraethoxysilane, octyltriethoxysilane, and 3-aminopropyltriethoxysilane in the initial sol. SEM studies reveal that a coating with about 400 nm thickness can be obtained. The inner surface properties of these capillaries were probed by measuring the EOF as a function of pH. The surface of this stationary phase contains octyl, amine, and residual silanol moieties; the amine and silanol groups determine the net charge on the inner surface of the capillary and can produce a switchable EOF (anodal/cathodal). The performances of the columns were evaluated by open tubular capillary electrochromatography using a wide range of compounds (polycyclic aromatic hydrocarbons, aromatic acids, and aromatic amines).

show abstract

Application of open tubular electrochromatography for acidic and basic analytes

Cited by 7 publications

References 28 publications

Analytical separations in open‐tubular capillary electrochromatography

Analytical separations in open‐tubular capillary electrochromatography

Metallomesogenic stationary phase for open‐tubular capillary electrochromatography

Open tubular columns with mixed‐mode reversed‐phase and weak anion‐exchange stationary phase for capillary electrochromatography

Contact Info

Product

Resources

About