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Lucy CA, Ries KR, Mensinger ZL. Resources to bring diversity, equity, inclusion, and respect into analytical chemistry classrooms. Anal Bioanal Chem 2022; 414:7943-7947. [PMID: 36181514 DOI: 10.1007/s00216-022-04345-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/16/2022] [Indexed: 11/27/2022]
Affiliation(s)
- Charles A Lucy
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada.
- Department of Chemistry, University of Victoria, Victoria, British Columbia, V8P 5C2, Canada.
| | - Kate R Ries
- Metropolitan State University, Saint Paul, MN, 55106, USA
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2
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Affiliation(s)
- Levi Garza
- Department of Chemistry, Whitworth University, Spokane, WA, 99251, USA
| | - Michael Jones
- Department of Biology and Chemistry, Azusa Pacific University, Azusa, CA, 91702, USA
| | - Caley B Craven
- Department of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2, Canada
| | - Charles A Lucy
- Department of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2, Canada
| | - Eric J Davis
- Department of Chemistry, Whitworth University, Spokane, WA, 99251, USA.
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3
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Abstract
Abstract
A capillary zone electrophoresis (CZE) method was developed to separate and determine chlorinated phenols in water and soil samples. A mixture of 16 chlorinated phenols was resolved in 25 min by using a 77 cm (70 cm to detector) × 75 μm fused silica capillary with 0.015M tetraborate/0.045M phosphate (pH 7.3) buffer at 22 kV. Calibration linearities for water samples in the low parts-permillion range were good (correlation coefficient > 0.99) for all solutes except p-chlorophenol. Average precision was 17% relative standard deviation. Typical detection limits were in the 200 μg/L range. Recoveries of chlorinated phenols from synthetic soil samples with methanol were quantitative.
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Affiliation(s)
- Wayne E Rae
- University of Calgary, Department of Chemistry, 2500 University Dr N.W., Calgary, AB, T2N 1N4, Canada
| | - Charles A Lucy
- University of Calgary, Department of Chemistry, 2500 University Dr N.W., Calgary, AB, T2N 1N4, Canada
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Craven CB, Joyce CW, Lucy CA. Effect of nature of electrolytes on retention and selectivity in hydrophilic interaction liquid chromatography. J Chromatogr A 2019; 1584:80-86. [DOI: 10.1016/j.chroma.2018.11.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 11/10/2018] [Accepted: 11/14/2018] [Indexed: 10/27/2022]
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Abstract
The two-tailed cationic surfactant dioctadecyldimethyl ammonium bromide (DODAB) produces semi-permanent coatings that yield strongly reversed electroosmotic flow (EOF), for example -0.31 ± 0.01 cm2 kV-1 s-1 at pH 3.5. Moreover, these coatings are easy to prepare, regenerable, cost effective, and yield high efficiency (520 000-900 000 plates per m) separations of cationic proteins over many runs under acidic (pH 3.5) conditions. Given the quaternary amine functionality of DODAB, we were surprised to observe that DODAB coatings become unstable at pH > 7. At pH 7.2, the EOF of a DODAB coated capillary drifted from reversed to cathodic over only 5 runs, and protein separations became severely compromised. By pH 12, no EOF reversal was observed. Electrophoretic and mass spectrometric studies demonstrate that the coating decomposition involves a surface conversion of the quaternary amine in DODAB to a variety of products, although the exact mechanism remains elusive. Regardless, the results herein demonstrate that semi-permanent coatings based on cationic two-tailed surfactants such as DODAB are limited to separations using acidic buffers.
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Affiliation(s)
- Lisa Shulman
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, AB, Canada T6G 2G2.
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Wu D, Jiang P, Lucy CA. Linear solvation energy relationship (LSER) characterization of the normal phase retention mechanism on hypercrosslinked polystyrenes. J Chromatogr A 2018; 1543:40-47. [PMID: 29486887 DOI: 10.1016/j.chroma.2018.02.036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 02/18/2018] [Accepted: 02/19/2018] [Indexed: 11/24/2022]
Abstract
Linear solvation energy relationships (LSERs) were applied to retention on hypercrosslinked polystyrene on silica (HC-Tol) to elucidate the type and relative importance of molecular interactions between model solutes and the HC-Tol stationary phase. Classical amino phase and another hypercrosslinked phase (5-HGN) were used as reference columns. On both the HC-Tol and amino, polar interactions predominate and contribute to retention. Solute volume V has no impact on retention on the amino column, while V has a slightly negative influence on retention for the HC-Tol column. The differences in coefficient v between the amino and the HC-Tol columns might explain why the HC-Tol is capable of group-type separations. 5-HGN phase has smaller a and b values compared to HC-Tol, which means that 5-HGN is not as basic or acidic in terms of hydrogen bonds as is HC-Tol. This suggests that the hydrogen bonding character of the HC-Tol phase arises from its silica substrate.
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Affiliation(s)
- Di Wu
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada
| | - Ping Jiang
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada
| | - Charles A Lucy
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada.
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Wu D, Lucy CA. Linear solvation energy relationships in normal phase chromatography based on gradient separations. J Chromatogr A 2017; 1516:64-70. [DOI: 10.1016/j.chroma.2017.07.095] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Revised: 07/29/2017] [Accepted: 07/31/2017] [Indexed: 10/19/2022]
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Wu D, Lucy CA. Study of the slope of the linear relationship between retention and mobile phase composition (Snyder-Soczewiñski model) in normal phase liquid chromatography with bonded and charge-transfer phases. J Chromatogr A 2016; 1475:31-40. [PMID: 27852455 DOI: 10.1016/j.chroma.2016.10.068] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 10/23/2016] [Accepted: 10/24/2016] [Indexed: 10/20/2022]
Abstract
The Snyder model and the Soczewiñski model are compared on classic NPLC bonded phases using literature data, and on the charge transfer 2, 4-dinitroanilinopropyl (DNAP) column using experimentally collected data. Overall, the Snyder model slightly better predicts the n-slope than the Soczewiñski model. However, both models give comparable uncertainty in predicting n-slope for a given compound. The number of aromatic double bonds was the most suitable descriptor for estimating the relative n-slope of PAHs, as it correlated with behavior better than the number of aromatic rings and is simpler to calculate than the solute adsorption area. On the DNAP phase, a modified Soczewiñski model is suggested to allow for the significant contribution of the aromatic rings to the n-slope. For classic NPLC bonded phases and DNAP columns, the contribution of polar group to the n-slope parallels the adsorption energy of each polar group.
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Affiliation(s)
- Di Wu
- Department of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2 Canada
| | - Charles A Lucy
- Department of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2 Canada.
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Iverson CD, Gu X, Lucy CA. The hydrophilicity vs. ion interaction selectivity plot revisited: The effect of mobile phase pH and buffer concentration on hydrophilic interaction liquid chromatography selectivity behavior. J Chromatogr A 2016; 1458:82-9. [DOI: 10.1016/j.chroma.2016.06.061] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 06/16/2016] [Accepted: 06/18/2016] [Indexed: 11/28/2022]
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Pappoe MK, Naeeni MH, Lucy CA. Bromate peak distortion in ion chromatography in samples containing high chloride concentrations. J Chromatogr A 2016; 1444:57-63. [DOI: 10.1016/j.chroma.2016.03.045] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 03/14/2016] [Accepted: 03/17/2016] [Indexed: 10/22/2022]
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Jiang P, Lucy CA. Retentivity, selectivity and thermodynamic behavior of polycyclic aromatic hydrocarbons on charge-transfer and hypercrosslinked stationary phases under conditions of normal phase high performance liquid chromatography. J Chromatogr A 2016; 1437:176-182. [DOI: 10.1016/j.chroma.2016.02.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 02/02/2016] [Accepted: 02/03/2016] [Indexed: 11/17/2022]
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Iverson CD, Zhang Y, Lucy CA. Diazonium modification of porous graphitic carbon with catechol and amide groups for hydrophilic interaction and attenuated reversed phase liquid chromatography. J Chromatogr A 2015; 1422:186-193. [PMID: 26506445 DOI: 10.1016/j.chroma.2015.10.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 09/30/2015] [Accepted: 10/08/2015] [Indexed: 11/20/2022]
Abstract
Porous graphitic carbon (PGC) is an increasingly popular and attractive phase for HPLC on account of its chemical and thermal stability, and its unique separation mechanism. However, native PGC is strongly hydrophobic and in some instances excessively retentive. As part of our effort to build a library of hydrophilic covalently modified PGC phases, we functionalized PGC with catechol and amide groups by means of aryl diazonium chemistry to produce two new phases. Successful grafting was confirmed by X-ray photoelectron spectroscopy (XPS). Under HILIC conditions, the Catechol-PGC showed up to 5-fold increased retention relative to unmodified PGC and selectivity that differed from four other HILIC phases. Under reversed phase conditions, the Amide-PGC reduced the retentivity of PGC by almost 90%. The chromatographic performance of Catechol-PGC and Amide-PGC is demonstrated by separations of nucleobases, nucleosides, phenols, alkaline pharmaceuticals, and performance enhancing stimulants. These compounds had retention factors (k) ranging from 0.5 to 13.
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Affiliation(s)
- Chad D Iverson
- Department of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada
| | - Ya Zhang
- Department of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada
| | - Charles A Lucy
- Department of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada.
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Zhang Y, Lucy CA. Effect of injection matrix concentration on peak shape and separation efficiency in ion chromatography. J Chromatogr A 2014; 1371:177-83. [DOI: 10.1016/j.chroma.2014.10.056] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 10/14/2014] [Accepted: 10/20/2014] [Indexed: 10/24/2022]
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14
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Iverson CD, Lucy CA. Aniline-modified porous graphitic carbon for hydrophilic interaction and attenuated reverse phase liquid chromatography. J Chromatogr A 2014; 1373:17-24. [PMID: 25464992 DOI: 10.1016/j.chroma.2014.11.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Revised: 10/30/2014] [Accepted: 11/02/2014] [Indexed: 11/28/2022]
Abstract
Most stationary phases for hydrophilic interaction liquid chromatography (HILIC) and reversed phase liquid chromatography (RPLC) are based on silica. Porous graphitic carbon (PGC) is an attractive alternative to silica-based phases due to its chemical and thermal stability, and unique selectivity. However, native PGC is strongly hydrophobic and in some instances excessively retentive. PGC particles with covalently attached aniline groups (Dimethylaniline-PGC and Aniline-PGC) were synthesized to alter the surface polarity of PGC. First, the diazonium salt of N,N-dimethyl-p-phenylenediamine or 4-nitroaniline was adsorbed onto the PGC surface. The adsorbed salt was reduced with sodium borohydride and (Aniline-PGC only) the nitro group was further reduced with iron powder to the aniline. X-ray photoelectron spectroscopy confirmed the surface functionalities and that these moieties were introduced to the surface at concentrations of 0.9 and 2.1molecules/nm(2), respectively. These modified PGC phases (especially Aniline-PGC) were evaluated as HILIC and reversed phases. The Dimethylaniline-PGC phase displayed only weak HILIC retention of phenolic solutes. In contrast, the Aniline-PGC phase displayed up to nearly a 7-fold increase in HILIC retention vs. an aniline-silica phase and selectivity that differed from 10 other HILIC phases. Introduction of aniline groups to the PGC surface reduced the RPLC retentivity of PGC up to more than 5-fold and improved the separation efficiency up to 6-fold. The chromatographic performance of Aniline-PGC is demonstrated by separations of nucleotides, nucleosides, carboxylic acids, basic pharmaceuticals, and other compounds.
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Affiliation(s)
- Chad D Iverson
- Department of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada
| | - Charles A Lucy
- Department of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada.
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Wu D, Nedev GK, Lucy CA. Retention mechanism of hypercrosslinked polystyrene silica hybrid phase in normal phase chromatography. J Chromatogr A 2014; 1370:50-5. [DOI: 10.1016/j.chroma.2014.10.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 10/06/2014] [Accepted: 10/07/2014] [Indexed: 11/30/2022]
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16
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Ibrahim ME, Wahab MF, Lucy CA. Hybrid carbon nanoparticles modified core–shell silica: A high efficiency carbon-based phase for hydrophilic interaction liquid chromatography. Anal Chim Acta 2014; 820:187-94. [DOI: 10.1016/j.aca.2014.02.034] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Revised: 01/31/2014] [Accepted: 02/22/2014] [Indexed: 10/25/2022]
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Jiang P, Wu D, Lucy CA. Determination of void volume in normal phase liquid chromatography. J Chromatogr A 2014; 1324:63-70. [DOI: 10.1016/j.chroma.2013.11.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 11/06/2013] [Accepted: 11/12/2013] [Indexed: 11/28/2022]
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Affiliation(s)
- M. Farooq Wahab
- Department
of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada
| | - Jordan K. Anderson
- Department
of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada
| | - Mohamed Abdelrady
- Department
of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada
| | - Charles A. Lucy
- Department
of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada
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Wahab MF, Ibrahim MEA, Lucy CA. Carboxylate modified porous graphitic carbon: a new class of hydrophilic interaction liquid chromatography phases. Anal Chem 2013; 85:5684-91. [PMID: 23701017 DOI: 10.1021/ac400350x] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Stationary phases for hydrophilic interaction liquid chromatography (HILIC) are predominantly based on silica and polymer supports. We present porous graphitic carbon particles with covalently attached carboxylic acid groups (carboxylate-PGC) as a new HILIC stationary phase. PGC particles were modified by adsorbing the diazonium salt of 4-aminobenzoic acid onto the PGC, followed by reduction of the adsorbed salt with sodium borohydride. The newly developed carboxylate-PGC phase exhibits different selectivity than that of 35 HPLC columns, including bare silica, zwitterionic, amine, reversed, and unmodified PGC phases. Carboxylate-PGC is stable from pH 2.0 to 12.6, yielding reproducible retention even at pH 12.6. Characterization of the new phase is presented by X-ray photoelectron spectroscopy, thermogravimetry, zeta potentials, and elemental analysis. The chromatographic performance of carboxylate-PGC as a HILIC phase is illustrated by separations of carboxylic acids, nucleotides, phenols, and amino acids.
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Affiliation(s)
- M Farooq Wahab
- Department of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada
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Wahab MF, Pohl CA, Lucy CA. Colloidal aspects and packing behaviour of charged microparticulates in high efficiency ion chromatography. J Chromatogr A 2012; 1270:139-46. [DOI: 10.1016/j.chroma.2012.10.057] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 10/26/2012] [Accepted: 10/29/2012] [Indexed: 10/27/2022]
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Bahnasy MF, Lucy CA. A versatile semi-permanent sequential bilayer/diblock polymer coating for capillary isoelectric focusing. J Chromatogr A 2012; 1267:89-95. [DOI: 10.1016/j.chroma.2012.07.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Revised: 07/03/2012] [Accepted: 07/06/2012] [Indexed: 12/30/2022]
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22
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Lucy CA, Underhill RS. Characterization of the cationic surfactant induced reversal of electroosmotic flow in capillary electrophoresis. Anal Chem 2012; 70:1045. [PMID: 21644633 DOI: 10.1021/ac971476c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Yeung KK, Lucy CA. Isotopic separation of [(14)n]- and [(15)n]aniline by capillary electrophoresis using surfactant- controlled reversed electroosmotic flow. Anal Chem 2012; 70:3286-90. [PMID: 21644665 DOI: 10.1021/ac9801566] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Separation of isotopically labeled [(14)N]- and [(15)N]aniline was achieved using capillary electrophoresis based on the isotopic effect on pK(a). The effects of the buffer co-ion, pH, and electroosmotic mobility on the resolution are investigated in this paper. Electroosmotic flow (EOF) was controlled using the zwitterionic surfactant Rewoteric AM CAS U as buffer additive. The resultant EOF was anodic (reversed) and low in magnitude (0.6 × 10(-)(4) cm(2)/(V·s)). The resolution of [(14)N]- and [(15)N]aniline was 1.22. Addition of a cationic surfactant, cetyltrimethylammonium bromide, to the zwitterionic surfactant increased the magnitude of the anodic EOF. This EOF improved the resolution to 1.33 based on mobility counterbalance.
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Affiliation(s)
- K K Yeung
- Department of Chemistry, The University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada T2N 1N4
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24
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Ibrahim ME, Liu Y, Lucy CA. A simple graphical representation of selectivity in hydrophilic interaction liquid chromatography. J Chromatogr A 2012; 1260:126-31. [DOI: 10.1016/j.chroma.2012.08.064] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 08/16/2012] [Accepted: 08/21/2012] [Indexed: 10/27/2022]
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25
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Stanley B, Lucy CA. Micellar electrokinetic chromatography with acid labile surfactant. J Chromatogr A 2012; 1226:55-60. [DOI: 10.1016/j.chroma.2011.09.065] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 09/23/2011] [Accepted: 09/23/2011] [Indexed: 01/12/2023]
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Zandkarimi M, Shafaati A, Foroutan SM, A. Lucy C. Improvement of electrophoretic enantioseparation of amlodipine by polybrene. Iran J Pharm Res 2012; 11:129-36. [PMID: 25317194 PMCID: PMC3876563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In chiral and non-chiral electrophoretic resolution of basic drugs, adsorption of analytes to negatively charged capillary wall could lead to poor repeatability of migration time and peak area. In addition, chiral resolutions of basic drugs are commonly performed in low pH buffers. Therefore, longer analysis time due to suppression of electroosmotic flow (EOF) is another dilemma. In this work the improvement effect of polybrene (PB), a cationic polymer, on chiral separation of a model basic drug, amlodipine (AML), was investigated. PB both as a semi-permanent coating agent and as an additive in the running buffer was utilized. Better results were obtained with PB as a buffer additive. Compare to untreated bare silica without using PB in running buffer, addition of 0.0005% PB buffer decreased analysis time downed to 3 folds; efficiency improved up to 5 folds; limit of detection (LOD) and limit of quantification (LOQ) downed to 8 folds and within-day migration time and peak area repeatabilities, in terms of relative standard deviations (RSD) downed to 5 and 20 folds, respectively.
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Affiliation(s)
- Majid Zandkarimi
- School of Pharmacy, Zabol University of Medical Sciences, Zabol, Iran.
| | - Alireza Shafaati
- School of Pharmacy, Shaheed Beheshti University of Medical Sciences, Tehran, Iran. ,Corresponding author: E-mail:
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Paproski RE, Liang C, Lucy CA. High temperature normal phase liquid chromatography of aromatic hydrocarbons on bare zirconia. J Chromatogr A 2011; 1218:7948-55. [DOI: 10.1016/j.chroma.2011.08.087] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 08/25/2011] [Accepted: 08/28/2011] [Indexed: 11/29/2022]
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Oro NE, Lucy CA. High performance liquid chromatographic separations of gas oil samples and their hydrotreated products using commercial normal phases. J Chromatogr A 2011; 1218:7788-95. [DOI: 10.1016/j.chroma.2011.08.071] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 08/22/2011] [Accepted: 08/23/2011] [Indexed: 10/17/2022]
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Gulcev MD, Lucy CA. Effect of coating electrolytes on two-tailed surfactant bilayer coatings in capillary electrophoresis. Anal Chim Acta 2011; 690:116-21. [DOI: 10.1016/j.aca.2011.01.055] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Revised: 01/27/2011] [Accepted: 01/27/2011] [Indexed: 11/30/2022]
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30
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Wahab MF, Pohl CA, Lucy CA. Ion chromatography on carbon clad zirconia modified by diazonium chemistry and functionalized latex particles. Analyst 2011; 136:3113-20. [DOI: 10.1039/c1an15284j] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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31
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Chambers SD, Pohl CA, Lucy CA. Agglomerated carbon based phases for anion exchange chromatography. J Chromatogr A 2011; 1218:263-9. [DOI: 10.1016/j.chroma.2010.11.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Revised: 11/09/2010] [Accepted: 11/12/2010] [Indexed: 10/18/2022]
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32
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MacDonald AM, Bahnasy MF, Lucy CA. A modified supported bilayer/diblock polymer – Working towards a tunable coating for capillary electrophoresis. J Chromatogr A 2011; 1218:178-84. [DOI: 10.1016/j.chroma.2010.10.111] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2010] [Revised: 10/24/2010] [Accepted: 10/26/2010] [Indexed: 10/18/2022]
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Abstract
Hydrophilic interaction LC (HILIC) has gained wide acceptance in recent years due to its ability to retain and separate polar compounds such as pharmaceuticals. Most commercial HILIC phases are particle based, which limit the speed with which HILIC separations can be performed. Herein, agglomerated silica monolithic columns are prepared by electrostatically attaching polyionic latex particles onto a silica monolith by simply flushing a suspension of the ionic latex through a silica monolith. Such phases retain the high efficiency and permeability of the native silica monolith, while the agglomerated phase is easy to introduce and provides excellent mass transfer. High %ACN in the mobile phase dramatically increases the efficiency and retention, consistent with HILIC behavior. Test analytes such as benzoates, nucleotides and amino acids are separated with plate heights of 25-110 microm. The high permeability of monoliths allows HILIC separations to be performed with baseline resolution in less than 15 s. Electrostatic repulsion-hydrophilic liquid interaction chromatographic retention behavior of the latex-coated monoliths is verified using amino acids as test analytes.
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Gulcev MD, McGinitie TM, Bahnasy MF, Lucy CA. Surfactant bilayer coatings in narrow-bore capillaries in capillary electrophoresis. Analyst 2010; 135:2688-93. [DOI: 10.1039/c0an00279h] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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Chambers SD, McDermott MT, Lucy CA. Covalently modified graphitic carbon-based stationary phases for anion chromatography. Analyst 2009; 134:2273-80. [DOI: 10.1039/b911988d] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Lucy CA, MacDonald AM, Gulcev MD. Non-covalent capillary coatings for protein separations in capillary electrophoresis. J Chromatogr A 2008; 1184:81-105. [DOI: 10.1016/j.chroma.2007.10.114] [Citation(s) in RCA: 252] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2007] [Revised: 10/25/2007] [Accepted: 10/31/2007] [Indexed: 11/27/2022]
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Zhou T, Lucy CA. Hydrophilic interaction chromatography of nucleotides and their pathway intermediates on titania. J Chromatogr A 2008; 1187:87-93. [PMID: 18304561 DOI: 10.1016/j.chroma.2008.02.027] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2007] [Revised: 01/26/2008] [Accepted: 02/04/2008] [Indexed: 11/25/2022]
Abstract
Nucleotides and their pathway intermediates play important roles in all living species. They are essential cellular components in energy transfer, metabolic regulatory processes and biosynthesis. Titania (TiO(2)) has strong Lewis acid sites which have an affinity for the strongly electronegative phosphonate group of nucleotides. Herein a bare titania column (150 mm x 4.6 mm I.D., 3 microm) with UV detection at 254 nm was used for the separation of a set of nucleotides (AMP, ADP, ATP, UMP, UDP, UTP, GMP, GDP, GTP, CMP and CTP) and their intermediates (NAD, NADH, UDP-Glu and UDP-GluNAc). Addition of phosphate to the eluent suppresses the ligand-exchange interactions with the titania surface such that hydrophilic interaction chromatography (HILIC) separations may be performed. Increasing the %ACN resulted in increasing retention and efficiency (up to 13,000, 9500 and 4500 plates/m for AMP, ADP and ATP, respectively). The effects of pH, buffer concentration and other eluent anions (fluoride and acetate) were also studied. Fifteen nucleotides and their intermediates were separated in 26 min (R(minimum)>1.3) using an one-step gradient.
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Affiliation(s)
- Ting Zhou
- Department of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada
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Gulcev MD, Lucy CA. Factors Affecting the Behavior and Effectiveness of Phospholipid Bilayer Coatings for Capillary Electrophoretic Separations of Basic Proteins. Anal Chem 2008; 80:1806-12. [DOI: 10.1021/ac702408u] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Makedonka D. Gulcev
- Department of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada
| | - Charles A. Lucy
- Department of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, Alberta T6G 2G2, Canada
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Chambers SD, Lucy CA. Surfactant coated graphitic carbon based stationary phases for anion-exchange chromatography. J Chromatogr A 2007; 1176:178-84. [DOI: 10.1016/j.chroma.2007.10.108] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2007] [Revised: 10/24/2007] [Accepted: 10/31/2007] [Indexed: 11/26/2022]
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Abstract
The focus of this review is on current status and on-going developments in ion chromatography (IC) using monolithic phases. The use and potential of both silica and polymeric monoliths in IC is discussed, with silica monoliths achieving efficiencies upwards of 10(5) plates/m for inorganic ions in a few minutes or less. Ion exchange capacity can be introduced onto the monolithic columns through the addition of ion interaction reagents to the eluent, coating of the monolith with ionic surfactants or polyelectrolyte latexes, and covalent bonding. The majority of the studies to date have used surfactant-coated columns, but the stability of surfactant coatings limits this approach. Applications of monolithic IC columns to the separation of inorganic anions and cations are tabulated. Finally, a discussion on the recent commercialization of monolithic IC columns and the use of monolithic phases for IC peripherals such as preconcentrator columns, microextractors and suppressors is presented.
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Affiliation(s)
- Stuart D Chambers
- Department of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, Alberta, Canada
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42
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Yassine MM, Guo N, Zhong H, Li L, Lucy CA. Off-line coupling of preparative capillary zone electrophoresis with microwave-assisted acid hydrolysis and matrix-assisted laser desorption ionization mass spectrometry for protein sequencing. Anal Chim Acta 2007; 597:41-9. [PMID: 17658311 DOI: 10.1016/j.aca.2007.05.054] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2007] [Revised: 05/25/2007] [Accepted: 05/31/2007] [Indexed: 11/16/2022]
Abstract
An off-line coupling of capillary electrophoresis (CE) with microwave-assisted acid hydrolysis/matrix-assisted laser desorption ionization mass spectrometry (MAAH/MALDI) has been developed for protein identification and characterization. Preparative scale protein separations enable collection of 10-50 pmol of purified cytochrome c for subsequent sequencing using MAAH/MALDI. To reduce protein adsorption onto the silica surface, the cationic surfactant-based coatings, dimethylditetradecylammonium bromide and dimethyldioctadecylammonium bromide, are employed. The choice of the buffer conditions is critical for both the preparative CE and MAAH/MALDI method. The use of high buffer concentrations (100 mM Bis-tris) reduces electromigration dispersion, but suppressed MALDI ionization such that a peptide sequence coverage of only 80% was achieved at a sample loading of 40 g L(-1) of each cytochrome c. By reducing the buffer concentration to 25 mM Bis-tris, the sequence coverage increased to 95% at a sample loading of 40 g L(-1).
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Affiliation(s)
- Mahmoud M Yassine
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, Canada T6G 2G2
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Diress AG, Lucy CA. Self-assembled coating for modification of the electro-osmotic flow in nonaqueous capillary electrophoresis using formamide. CAN J CHEM 2007. [DOI: 10.1139/v07-077] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The use of pure nonaqueous solvents in capillary electrophoresis (CE) can alter the separation selectivity and enhance the solubility of hydrophobic compounds and enables the use of higher voltages. However, control of the electro-osmotic flow (EOF) is essential. In this work, we report the use of self-assembled coatings for EOF modification and elimination of analyte adsorptions onto silica capillaries in pure formamide. Bilayer capillary coatings derived from the double chain cationic surfactant dimethyldioctadecylammonium bromide (2C18DAB) reverses the EOF in buffers such as acetate, formate, and phosphate. Reversed EOF of >1.1 × 10–4 cm2/Vs enables the separation of the pharmaceutical drugs propranolol, metoprolol, chloroquine, and chloropheniramine in less than 5 min with efficiencies of 0.2–0.5 million plates/m (66 000 to 165 000 plates). Chemical and physical factors affecting the coating stability and their influence on separation speed and efficiency of the cationic drugs in formamide are also investigated.Key words: capillary electrophoresis, cationic surfactants, electro-osmotic flow, formamide, nonaqueous solvents.
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Abstract
This report describes the creation of semipermanent capillary coatings that are compatible with organic-water solvent systems in CE. The coatings are created by simply rinsing the fused-silica capillary with long double-chain cationic surfactants, such as dimethyl-ditetradecyl ammonium bromide (2C(14)DAB), dihexadecyldimethyl ammonium bromide (2C(16)DAB), and dimethyldioctadecyl ammonium bromide (2C(18)DAB). These surfactants generate semipermanent bilayer coatings on the capillary surface, which display a high degree of stability in buffers containing up to 60% v/v of organic solvents, such as methanol and ACN. The coating stability increases with increasing hydrophobicity of the surfactant, i.e., with increasing chain length. For instance, the EOF changes by only 1.2% in a 2C(18)DAB-coated capillary after 130 capillary volumes of rinsing with 60% v/v methanol containing buffer. The bilayer coatings allow separations to be performed without the need to regenerate the coating between runs or to maintain the EOF modifier in the run buffer. Rapid separations (<2 min) of anions and basic drugs with migration time reproducibility of less than 0.5% RSD and efficiencies of 0.4-0.6 million plates/m are obtained. In addition, selectivity changes for small anions and cationic drugs are also observed when the organic solvent content is adjusted.
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Affiliation(s)
- Abebaw G Diress
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, Canada
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45
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Glenn KM, Lucy CA, Haddad PR. Ion chromatography on a latex-coated silica monolith column. J Chromatogr A 2007; 1155:8-14. [PMID: 17306813 DOI: 10.1016/j.chroma.2007.01.098] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2006] [Revised: 01/24/2007] [Accepted: 01/26/2007] [Indexed: 11/15/2022]
Abstract
A silica monolith column (Merck Chromolith, 100 mm x 4.6 mm) has been coated with Dionex AS9-SC latex nanoparticles to convert the column into an anion-exchange stationary phase. For comparison purposes, a reversed-phase silica monolith was also converted into an anion-exchange column by coating with the cationic surfactant didodecyldimethylammonium bromide (DDAB). Separations of common inorganic anions were carried out using 7.5 or 5.0 mM 4-hydroxybenzoic acid at pH 7.0 along with suppressed conductivity detection. Direct comparisons were then made between the two columns in terms of selectivity, efficiency and stability. The latex-coated column was on average 50% more efficient than the DDAB-coated column. A 10% decrease in retention times was observed on the DDAB column over 11 h of continuous eluent flow, while the latex coating exhibited <1% change in retention even after 2.5 months of periodic use.
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Affiliation(s)
- Karen M Glenn
- Department of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, AB, Canada T6G 2G2
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46
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MacDonald AM, Lucy CA. Highly efficient protein separations in capillary electrophoresis using a supported bilayer/diblock copolymer coating. J Chromatogr A 2006; 1130:265-71. [PMID: 16777117 DOI: 10.1016/j.chroma.2006.05.042] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2006] [Revised: 05/06/2006] [Accepted: 05/16/2006] [Indexed: 10/24/2022]
Abstract
A surfactant/polymer wall coating consisting of the doubly chained cationic surfactant dimethyldioctadecylammonium bromide (DODAB) and polyoxyethylene (POE) 40 stearate is investigated. The coating is formed by simply rinsing a capillary with a solution containing DODAB and POE 40 stearate. The resultant coating is semi-permanent--demonstrating stable electroosmotic flow (EOF) even after a 60 min high pressure rinse with buffer. The EOF (-0.45+/-(0.23) x 10(-4) cm(2) V(-1) s(-1) at pH 7.4) is suppressed by more than a factor of ten compared to that observed for DODAB alone. Model protein mixtures were separated over a pH range of 3-10 with efficiencies of up to greater than 1 million plates/m for the basic proteins cytochrome c, lysozyme, ribonuclease A and alpha-lactalbumin, and the acidic proteins insulin chain A, trypsin inhibitor, and alpha-chymotrypsinogen A. Migration time reproducibility was 0.5-4.0% from run to run and 0.6-4.3% from day to day. Protein recoveries with this coating ranged from 84% to 97%.
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Affiliation(s)
- Amy M MacDonald
- Department of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, Alta., Canada T6G 2G2
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47
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Pelletier S, Lucy CA. Fast and high-resolution ion chromatography at high pH on short columns packed with 1.8μm surfactant coated silica reverse-phase particles. J Chromatogr A 2006; 1125:189-94. [PMID: 16782112 DOI: 10.1016/j.chroma.2006.05.059] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2006] [Revised: 05/17/2006] [Accepted: 05/19/2006] [Indexed: 11/16/2022]
Abstract
Rapid ion chromatographic separations of small inorganic anions are performed on columns packed with high-pH resistant Zorbax Extend-C18 1.8 microm silica particles. Seven anions (iodate, chloride, nitrite, bromide, nitrate, phosphate, sulphate) are separated with 1.3 and 2 cm long x 0.46 cm I.D. C18 columns coated with the surfactant didodecyldimethylammonium bromide (DDAB). A 40 s separation is achieved at 2 mL/min with a 2.5 mM 4-hydroxybenzoic acid eluent at pH 10. Finally, the DDAB removal procedure is improved to eliminate the pressure build-up caused by precipitation of the surfactant in the column upon uncoating.
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Affiliation(s)
- Sarah Pelletier
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alta. T6G 2G2, Canada
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48
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Abstract
Preparative capillary zone electrophoresis separations of cytochrome c from bovine and horse heart are performed efficiently in a surfactant-coated capillary. The surfactant, dimethylditetradecylammonium bromide (2C(14)DAB), effectively eliminated protein adsorption from the capillary surface, such that symmetrical peaks with efficiencies of 0.7 million plates/m were observed in 50-microm id capillaries when low concentrations of protein were injected. At protein concentrations greater than 1 g/L, electromigration dispersion became the dominant source of band broadening and the peak shape distorted to triangular fronting. Matching of the mobility of the buffer co-ion to that of the cytochrome c resulted in dramatic improvements in the efficiency and peak shape. Using 100 mM bis(2-hydroxyethyl)imino-tris(hydroxymethyl)methane phosphate buffer at pH 7.0 with a 100-microm id capillary, the maximum sample loading capacity in a single run was 160 pmol (2.0 microg) of each protein.
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Affiliation(s)
- Mahmoud M Yassine
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
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49
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Pelletier S, Lucy CA. Achieving rapid low-pressure ion chromatography separations on short silica-based monolithic columns. J Chromatogr A 2006; 1118:12-8. [PMID: 16616176 DOI: 10.1016/j.chroma.2006.03.072] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2005] [Revised: 03/22/2006] [Accepted: 03/22/2006] [Indexed: 11/16/2022]
Abstract
Short silica-based monolithic columns (0.5-1 cm) are coated with the surfactant didodecyldimethylammonium bromide (DDAB) and used for fast ion exchange separations of small inorganic anions. Sources of extra-column band broadening are assessed and minimized to obtain separations of seven analytes (iodate, chloride, nitrate, bromide, nitrite, phosphate, sulphate) in two minutes at 2 mL/min. Eluents used are 6 and 9 mM 4-cyanophenol at pH 7.3-7.4 or 5 mM 4-hydroxybenzoic acid at pH 5.6. DDAB coating stability is improved by 15-fold by the addition of a DDAB coated pre-column before the injection valve. Separations are obtained using a low-pressure glass syringe.
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Affiliation(s)
- Sarah Pelletier
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alta., Canada T6G 2G2
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50
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Harrison CR, Sader JA, Lucy CA. Sulfonium and phosphonium, new ion-pairing agents with unique selectivity towards polarizable anions. J Chromatogr A 2006; 1113:123-9. [PMID: 16488425 DOI: 10.1016/j.chroma.2006.01.132] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2005] [Revised: 01/26/2006] [Accepted: 01/31/2006] [Indexed: 11/15/2022]
Abstract
Ion-pair chromatography (IPC) almost universally relies upon ammonium-based ion-pairing agents (IPAs) for anion separations. This work compares tetrabutylammonium (TBA) with tetrabutylphosphonium (TBP) and tributylsulfonium (TBS). To best understand the retention behavior analytes used for characterization of the IPAs spanned the Hofmeister series; from kosmotropic monoanions (iodate, chloride, nitrite) and intermediate anions (nitrate, bromide) to chaotropic ions (perchlorate, thiocyanate, iodide). The studies demonstrate that tetrabutylphosphonium is the most chaotropic IPA, followed by tetrabutylammonium and finally tributylsulfonium is the least chaotropic. In the case of the chaotropic anions, the retention of perchlorate was least with tributylsulfonium, and greatest for tetrabutylphosphonium, with tetrabutylammonium being intermediate. The multivalent kosmotropic anions (sulfate, chromate, thiosulfate) demonstrated unique selectivity changes depending on the kosmotropic/chaotropic nature of the IPA. Demonstrating increases in retention with increasing IPA concentration only with tributylsulfonium, whereas the more chaotropic IPAs universally decreased the retention of the multivalent anions.
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Affiliation(s)
- Christopher R Harrison
- Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alta., Canada T6G 2G2
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