Separation of acidic compounds by strong anion-exchange capillary electrochromatography

Ye, Mingliang; Zou, Hanfa; Liu, Zhen; Ni, Jincheng

doi:10.1016/s0021-9673(00)00397-6

Cited by 72 publications

(61 citation statements)

References 32 publications

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“…It was concluded that peptide CEC separations depend on an interplay between electrostatic interactions, hydrophobic interactions, and electrophoretic mobility. Ye et al [38] compared CEC and CZE separations of small peptides, studying selectivity, retention order, and the influence of ionic strength at a constant voltage. Fu et al [39] investigated the ionic strength dependence of peptide retention in hydrophilic interaction CEC with an SCX stationary phase.…”

Section: Introductionmentioning

confidence: 99%

Electrochromatographic retention of peptides on strong cation‐exchange stationary phases

Nischang¹,

Höltzel²,

Tallarek³

2010

Electrophoresis

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We analyze the systematic and substantial electrical field-dependence of electrochromatographic retention for four counterionic peptides ([Met5]enkephalin, oxytocin, [Arg8]vasopressin, and luteinizing hormone releasing hormone (LHRH) ) on a strong cation-exchange (SCX) stationary phase. Our experiments show that retention behavior in the studied system depends on the charge-selectivity of the stationary phase particles, the applied voltage, and the peptides' net charge. Retention factors of twice positively charged peptides ([Arg8]vasopressin and LHRH at pH 2.7) decrease with increasing applied voltage, whereas lower charged peptides (oxytocin and [Met5]enkephalin at pH 2.7, [Arg8]vasopressin and LHRH at pH 7.0) show a concomitant increase in their retention factors. The observed behavior is explained on the basis of electrical fieldinduced concentration polarization (CP) that develops around the SCX particles of the packing. The intraparticle concentration of charged species (buffer ions, peptides) increases with increasing applied voltage due to diffusive backflux from the enriched CP zone associated with each SCX particle. For twice charged and on the SCX phase strongly retained peptides the local increase in mobile phase ionic strength reduces the electrostatic interactions with the stationary phase, which explains the decrease of retention factors with increasing applied voltage and CP intensity. Lower charged and weaker retained peptides experience a much stronger relative intraparticle enrichment than the twice-charged peptides, which results in a net increase of retention factors with increasing applied voltage. The CP-related contribution to electrochromatographic retention of peptides on the SCX stationary phase is modulated by the applied voltage, the mobile phase ionic strength, and the peptides' net charge and could be used for selectivity tuning in difficult separations.

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Section: Introductionmentioning

confidence: 99%

Electrochromatographic retention of peptides on strong cation‐exchange stationary phases

Nischang¹,

Höltzel²,

Tallarek³

2010

Electrophoresis

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“…While water samples usually do not require pre-treatment, both solid and gas samples must first be subjected to extraction. A variety of approaches to determine SCCAs in different matrices have been reported, including classical capillary electrophoresis [1], [31]- [34], capillary zone electrophoresis [27], [31], [35]- [41], isotachophoresis [42], [43], and capillary electrochromatography [44]. Each of these versions all acids [46].…”

Section: Selected Aplicationsmentioning

confidence: 99%

Capillary Electrophoresis in Determination of Low Molecular Mass Organic Acids

Wasielewska¹,

Banel²,

Zygmunt³

2014

IJESD

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Abstract-This paper presents overviews the capabilities of capillary electrophoretic techniques to determine low molecular mass organic acids in a variety of aqueous, gas and solid samples. It mainly focuses on short -chain carboxylic acids containing one or more carboxylic groups and possibly some other functional groups (hydroxyl, keto-, amino-etc.). Finally the procedures applied to the determine the acids in different matrices are shortly characterized.The principles of capillary electrophoresis its advantages over gas and liquid chromatographic separation and detection modes are briefly discussed. Finally, the brief overview of the technique is followed by characterization of CE based procedures for the analysis of a variety of samples such as food, environmental, biological etc. for the content of organic acids, mainly those with carboxylic groups.Index Terms-Capillary electrophoresis, low molecular mass organic acids.

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“…However, Vissers and Claessens reported some differences in selectivity between RP-CEC and micro-HPLC [31]. Ye et al reported that the retention of acidic compounds increased with the increase of electric field in SAX-CEC [32]. According to Eq.…”

Section: Effects Of Pressure and Voltagementioning

confidence: 99%

Pressurized capillary electrochromatography separation of peptides with strong cation exchange and hydrophilic interaction

Zhang

Gao²,

Jiang

et al. 2003

J of Separation Science

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Pressurized capillary electrochromatography separation of peptides with strong cation exchange and hydrophilic interaction A pressurized capillary electrochromatography (pCEC) instrument with solvent gradient capability has been used for the separation of a peptide mixture. Retention mechanism and selectivity of the peptides were studied by pCEC using a strong cation exchange (SCX) column. The effects of applied voltage, supplementary pressure, organic modifier concentration, ionic strength, and pH value on pCEC separation were investigated. It was found that the retention mechanism of the peptides in this system is based on a mixed mode of hydrophilic interaction, strong cation exchange, and electrophoresis. Compared with the separation results obtained by reverse phase pCEC and capillary electrophoresis (CE), this mixed-mode pCEC is more powerful for the separation of hydrophilic peptides with similar charge-to-mass ratio.

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Separation of acidic compounds by strong anion-exchange capillary electrochromatography

Cited by 72 publications

References 32 publications

Electrochromatographic retention of peptides on strong cation‐exchange stationary phases

Electrochromatographic retention of peptides on strong cation‐exchange stationary phases

Capillary Electrophoresis in Determination of Low Molecular Mass Organic Acids

Pressurized capillary electrochromatography separation of peptides with strong cation exchange and hydrophilic interaction

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