Open‐tubular capillary electrochromatography/electrospray ionization‐mass spectrometry using polymeric surfactant as a stationary phase coating

Zhu, Xiaofeng; Kamande, Mary W.; Thiam, Serigne; Kapnissi, Constantina P.; Mwongela, Simon M.; Warner, Isiah M.

doi:10.1002/elps.200305713

Cited by 26 publications

(25 citation statements)

References 25 publications

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“…The applications of CEC-MS for achiral analysis continued to increase in the last 2-3 years as a convenient approach for small molecules, such as peptides [89,90], carbohydrates [91,92], pharmaceutical samples [93,94], and other small organic compounds [95]. Readers are also referred to a recent review from Barrachina and co-workers [96] entitled "State-of-the-art of the hyphenation of capillary electrochromatography with mass spectrometry".…”

Section: Applications Of Achiral Cec-msmentioning

confidence: 97%

“…CEC-MS has also been investigated for the analysis of various pharmaceuticals [92,93]. The use of CEC-MS seems to be promising in the analysis of drugs and metabolites, because in pharmaceutical analysis the commonly used mobile phases (e.g., ACN/water mixtures when delivered at a low flow rate) are ESI-MS-compatible.…”

Section: Applications Of Achiral Cec-msmentioning

confidence: 99%

“…Despite the use of two columns (one packed and the other open tube), no dispersive effect was observed with high peak efficiency. Very recently, in a novel approach, a polymeric surfactant-coated open-tubular CEC-TOF-MS was reported for the analysis of various b-blockers and benzodiazepine analytes [93]. A bilayer of two polymers (polydiallyl dimethyl ammonium chloride and polysodium N-undecyl sulfate) was coated on the capillary inner walls via adsorption and physical interactions.…”

Section: Applications Of Achiral Cec-msmentioning

confidence: 99%

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Capillary electrophoresis‐mass spectrometry: Recent advances to the analysis of small achiral and chiral solutes

Shamsi

Miller

2004

Electrophoresis

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We describe here the state-of-the-art development of on-line capillary electrophoresis-mass spectrometry (CE-MS) over the last two years. Technological developments included are novel designs of new interfaces and ionization sources, new capillary coatings, buffers, and micelles as well as application of various modes of CE-MS published in the recent literature. The areas of CE-MS application in analysis of small achiral and chiral solutes are covered in sections that highlight the recent advances and possibilities of each mode of CE-MS. Application areas reviewed in this paper include achiral and chiral pharmaceuticals, agrochemicals, carbohydrates, and small peptides. The separation of enantiomers using micellar electrokinetic chromatography (MEKC)-MS with molecular micelles and capillary electrochromatography (CEC)-MS using pack tapered columns appears to provide good tolerance to electrospray stability for routine on-line CE-MS. These two modes seem to be very suitable for sensitive detection of chiral pharmaceuticals in biological samples, but their use will probably increase in the near future. Overall, it seems that one mode of CE-MS, in particular capillary zone electrophoresis (CZE)-MS, is now recognized as established technique for analysis of small charged solutes, but other modes, such as MEKC-MS and CEC-MS, are still within a period of development in terms of both MS-compatible pseudostationary phases and columns as well as applications.

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Section: Applications Of Achiral Cec-msmentioning

confidence: 97%

Section: Applications Of Achiral Cec-msmentioning

confidence: 99%

Section: Applications Of Achiral Cec-msmentioning

confidence: 99%

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Capillary electrophoresis‐mass spectrometry: Recent advances to the analysis of small achiral and chiral solutes

Shamsi

Miller

2004

Electrophoresis

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“…This usually provides higher efficiencies and rapid analysis. They have, over the years, been extensively used in a BGE [74][75][76][77][78][79][80], in a polyelectrolyte multilayer coating [63,74,[81][82][83], and in a CE-MS system [84][85][86].…”

Section: Methods Development and Validationmentioning

confidence: 99%

Method Development by Use of Capillary Electrophoresis and Applications in Pharmaceutical, Biological and Natural Samples

Kapnissi‐Christodoulou¹

2012

Electrophoresis

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In addition, hydrogen bonding, dipole-dipole, and dispersive interactions can contribute to the solute partitioning between the two phases [4][5][6].CE was originally considered as a powerful analytical tool for the analysis of biological macromolecules. It has though, over the years, been extensively used for the separation of other compounds, such as chiral drugs, food additives, pesticides, inorganic ions, organic acids, and others. In this chapter, the ability of CE, and particularly CZE and MEKC, to be used for the qualitative and quantitative determination of compounds in pharmaceutical, biological and natural samples is investigated. In each approach, a number of studies are reported and discussed. These studies involve establishment of optimum separation conditions, method validation, optimization of sample-preparation procedure and application for the determination of the analytes under study in real samples. The first part of this chapter involves the determination of polyphenolic compounds using CZE with UVVis detector in red and white wines, while the second part involves the determination of pharmaceutical compounds in biological samples, such as blood and urine, using the hyphenated technique CE-MS (mass spectrometry). The third and final part emphasizes the importance of MEKC in chiral analysis since it has been known that usually only one enantiomer is active, while the other may be less active, inactive or has adverse effects. Determination of polyphenolic compounds in natural samplesPolyphenolic compounds exist in a variety of natural products, such as fruits, vegetables, beverages (tea, wine and juices), honey, cacao and herbs. They attract a lot of interest due to their beneficial implication in human health. They have been widely studied due to their antioxidant capacity and their association with several pathological conditions, such as hypertension, cardiovascular disease, dementia, and even cancer [7][8][9]. Therefore, due to their health significance, numerous analytical methods have, over the last decades, been developed for their separation, identification and quantitation in natural products [10][11][12][13].According to literature, the simplest CE method, CZE, proved to be the best method for the determination of polyphenolic compounds in wine samples [14][15][16][17]. In such studies, and in each case, when the optimum CZE method was applied to different red and white wines, it was established that red wines have higher levels of polyphenolic compounds than white wines and that the polyphenolic composition varies among different wines.

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“…These novel coatings allow for facile column fabrication and exceptional separation performance for both chiral and achiral analytes. [23][24][25][26][27] Herein, we report the development of a rapid CE method for studying in vitro post-translational modification-induced protein oligomerization. Capillaries coated with poly (diallyldimethylammonium chloride) (PDADMAC) were used to separate homooligomeric cytochrome c species.…”

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confidence: 99%

Capillary Electrophoretic Screening for the Inhibition of Homocysteine Thiolactone-Induced Protein Oligomerization

et al. 2007

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We report the first demonstration of rapid electrophoretic monitoring of homocysteine thiolactoneinduced protein oligomerization (HTPO), a unique type of post-translational protein modification that may have clinical significance as an indicator of cardiovascular and neurovascular diseases. HTPO of the model protein bovine cytochrome c was initiated in vitro. The relative monomer and aggregate levels of the resultant protein mixtures were determined following separation using capillaries coated with the cationic polymer, poly(diallyldimethylammonium chloride). UV detection provided adequate sensitivity for the monitoring of higher order species, which exist at relatively low concentrations in the protein reaction mixture as compared to the monomeric species. Separations performed under standard injection conditions were optimized on the basis of applied voltage and sample denaturation conditions. Separations performed using short-end injection allowed for more rapid analyses, typically in less than 70 s. Relative errors for run-to-run migration times were less than 0.5%. This novel oligomeric system provides a rapid and straightforward in vitro method to screen therapeutic agents for their ability to inhibit HTPO. Changes in peak area for monomer and aggregate species were used to assess HTPO inhibition as a function of pyridoxal 5-phosphate (PLP) concentration. PLP was shown to effectively inhibit HTPO in vitro. Rapid analysis times of ~1.5 min were achieved for inhibition screening.Hyperhomocysteinemia is a disorder characterized by elevated plasma levels of the naturally occurring amino acid homocysteine (Hcy), which has been identified as an independent risk factor for cardiovascular disease. 1,2 Although the exact function of Hcy in the pathogenesis of cardiovascular disease remains unknown, there is a growing body of evidence that suggests Hcy thiolactone (HTL), the thioester metabolite of Hcy, is a contributing agent. 3-6 HTL is produced in vivo via enzymatic aminoacyl-tRNA synthase pathways at a rate proportional to extracellular Hcy concentration. 7 Thus, it is likely that HTL production is enhanced to some degree in individuals with hyperhomocysteinemia.Post-translational protein modification by HTL involves the site-specific acylation of lysine residues at ε-amino moieties to yield free thiols in the form of protein homocystamide (Scheme 1). 8,9 If left untreated, protein homocystamide can undergo spontaneous in vitro intermolecular disulfide bonding to yield oligomeric species. 10 Protein oligomerization can give rise to a range of adverse physiological affects. For example, oligomeric proteins often exhibit decreased biological activity, decreased solubility, 8 and increased immunogenicity. 11 As one would expect, the extent of physiological dysfunction caused by oligomerization *To whom correspondence should be addressed. strongin@pdx.edu. Tel: (225) In Vitro Protein ModificationProtein reaction mixtures were prepared by dissolving HTL (2.5 mM), and cyt c (10 mg/mL) in pH 7.4, 100 mM so...

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Open‐tubular capillary electrochromatography/electrospray ionization‐mass spectrometry using polymeric surfactant as a stationary phase coating

Cited by 26 publications

References 25 publications

Capillary electrophoresis‐mass spectrometry: Recent advances to the analysis of small achiral and chiral solutes

Capillary electrophoresis‐mass spectrometry: Recent advances to the analysis of small achiral and chiral solutes

Method Development by Use of Capillary Electrophoresis and Applications in Pharmaceutical, Biological and Natural Samples

Capillary Electrophoretic Screening for the Inhibition of Homocysteine Thiolactone-Induced Protein Oligomerization

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