1
|
Sanders KL, Edwards JL. Nano-liquid chromatography-mass spectrometry and recent applications in omics investigations. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2020; 12:4404-4417. [PMID: 32901622 PMCID: PMC7530103 DOI: 10.1039/d0ay01194k] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Liquid chromatography coupled to mass spectrometry (LC-MS) is one of the most powerful tools in identifying and quantitating molecular species. Decreasing column diameter from the millimeter to micrometer scale is now a well-developed method which allows for sample limited analysis. Specific fabrication of capillary columns is required for proper implementation and optimization when working in the nanoflow regime. Coupling the capillary column to the mass spectrometer for electrospray ionization (ESI) requires reduction of the subsequent emitter tip. Reduction of column diameter to capillary scale can produce improved chromatographic efficiency and the reduction of emitter tip size increased sensitivity of the electrospray process. This improved sensitivity and ionization efficiency is valuable in analysis of precious biological samples where analytes vary in size, ion affinity, and concentration. In this review we will discuss common approaches and challenges in implementing nLC-MS methods and how the advantages can be leveraged to investigate a wide range of biomolecules.
Collapse
|
2
|
Zhang H, Wang B, Seehafer K, Bunz UHF. Sensor Array Based Determination of Edman Degradated Amino Acids Using Poly(p-phenyleneethynylene)s. Chemistry 2020; 26:7779-7782. [PMID: 32181541 PMCID: PMC7383564 DOI: 10.1002/chem.202001262] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Indexed: 12/18/2022]
Abstract
A cross‐reactive optical sensor array based on poly(p‐phenyleneethynylene)s (PPEs) determines Edman degraded amino acids. We report a sensor array composed of three anionic PPEs P1–P3, and their electrostatic complexes with metal ions (Fe2+, Cu2+, Co2+). We recorded distinct fluorescence intensity response patterns as “fingerprints” of this chemical tongue toward standard phenylthiohydantoin (PTH) amino acids—degradation products of the Edman process. These “fingerprints” were converted into canonical scores by linear discrimination analysis (LDA), which differentiates all of the PTH‐amino acids. This array discriminates PTH‐amino acid residues degraded from an oligopeptide through Edman sequencing. This approach is complementary to chromatography approaches which rely on mass spectrometry; our array offers the advantage of simplicity.
Collapse
Affiliation(s)
- Hao Zhang
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Benhua Wang
- College of Chemistry & Chemical Engineering, Central South University, Changsha, 410083, Hunan Province, China
| | - Kai Seehafer
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany
| | - Uwe H F Bunz
- Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.,Centre for Advanced Materials, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany
| |
Collapse
|
3
|
Isoda M, Fukuma M, Harata A. Ultraviolet-Excitation Photothermal Heterodyne Interferometer as a Micro-HPLC Detector. ANAL SCI 2019; 35:1311-1315. [PMID: 31827036 DOI: 10.2116/analsci.19p190] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The first demonstration of a photothermal heterodyne interferometer (PHI) combined with micro-HPLC (high-performance liquid chromatography) is reported. A semiconductor laser (375 nm) was used for excitation, and the temperature change caused by heat released from photoexcited species was detected with a He-Ne laser (632.8 nm). The temperature-dependent refractive index change of the solvent modified the optical path of the probe beam. The phase difference between two arms of the interferometer, one passing through the heated sample and another as a reference, was sensitively detected with the PHI. The nitro-polycyclic aromatic hydrocarbon and vitamin mixture separated via micro-HPLC was successfully detected with the PHI as well as a UV detector. The detection limit of the PHI for riboflavin in the absorbance units was 77 times better than that of the commercial UV detector. The detection limit of the PHI with a small flow cell (6 nL) was the same as that with a large flow cell (18 nL) for 1-nitropyrene.
Collapse
Affiliation(s)
- Miki Isoda
- Department of Molecular and Material Sciences, Kyushu University
| | - Makoto Fukuma
- Department of Molecular and Material Sciences, Kyushu University
| | - Akira Harata
- Department of Molecular and Material Sciences, Kyushu University
| |
Collapse
|
4
|
Sandy KE, Condarcure AM, Sutton CT, Baker CA, Gallagher ES, Bright LK, Aspinwall CA. Rapid Formation of Polymer Frits in Fused Silica Capillaries Using Spatially defined Thermal Free-Radical Initiated Polymerization. SEPARATION SCIENCE PLUS 2018; 1:753-758. [PMID: 34316536 DOI: 10.1002/sscp.201800126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Column preparation in capillary chromatography commonly relies upon the generation of on-column porous frits. Here, we report a simple, robust and low-cost approach for preparing polymer frits on-column, in a rapid and spatially controlled manner using thermal free-radical initiated polymerization. In this approach, a simple, temperature-controlled heating apparatus is positioned adjacent to a 100 μm i.d. fused-silica capillary for a defined duration. Frits were synthesized in 3-(trimethoxysilyl)propyl methacrylate modified capillaries using a monomer solution of 2,2-azobisisobutyronitrile, glycidyl methacrylate, ethylene glycol dimethacrylate, and decanol. Frit length and stability were investigated as a function of polymerization time and temperature. Frit length was easily controlled via a combination of polymerization time and temperature and position was readily controlled using a simple mechanical placement jig. Thermal initiated frits were stable throughout column packing and did not require removal of the capillary polyimide coating. The thermal initiation approach offers higher throughput, with polymerization times of < 2 min compared to ≥ 30 min for UV-initiated polymerization and significantly reduces the cost, enabling broader access to on-column frit technology for a variety of capillary separation applications.
Collapse
Affiliation(s)
- Kendall E Sandy
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, 85721, AZ
| | | | - Corey T Sutton
- Department of Chemistry, University of Tennessee, Knoxville, 37996, TN
| | | | - Elyssia S Gallagher
- Department of Chemistry and Biochemistry, Baylor University, Waco, 76706, TX
| | - Leonard K Bright
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, 85721, AZ
| | - Craig A Aspinwall
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, 85721, AZ.,Department of Biomedical Engineering, University of Arizona, Tucson, 85721, AZ.,Bio5 Institute, University of Arizona, Tucson, 85721, AZ
| |
Collapse
|
5
|
Proskurnin MA, Bendrysheva SN, Smirnova AP. Thermal lens spectrometry in electromigration methods of analysis. JOURNAL OF ANALYTICAL CHEMISTRY 2016. [DOI: 10.1134/s1061934816050105] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
6
|
Proskurnin MA, Volkov DS, Gor’kova TA, Bendrysheva SN, Smirnova AP, Nedosekin DA. Advances in thermal lens spectrometry. JOURNAL OF ANALYTICAL CHEMISTRY 2015. [DOI: 10.1134/s1061934815030168] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
7
|
Liu M, Franko M. Progress in Thermal Lens Spectrometry and Its Applications in Microscale Analytical Devices. Crit Rev Anal Chem 2014; 44:328-53. [DOI: 10.1080/10408347.2013.869171] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
|
8
|
Abstract
Although there are many publications related to technological or methodological developments of CEC, few focus on the analysis of natural products, especially phytochemical bioactive compounds. This review summarized the application of CEC in the analysis of phytochemical bioactive components, including flavonoids, nucleosides, steroids, lignans, quinones and coumarins, as well as fingerprint analysis of herbs. The strategies for optimization of CEC conditions and detection were also discussed.
Collapse
Affiliation(s)
- Feng-qing Yang
- Department of Pharmaceutics, College of Chemistry and Chemical Engineering, Chongqing University, Chongqing, P. R. China
| | | | | |
Collapse
|
9
|
Debowski JK. SELECTED APPLICATIONS OF CAPILLARY ELECTROCHROMATOGRAPHY IN THE PHARMACEUTICAL INDUSTRY: TO BUY OR NOT TO BUY? J LIQ CHROMATOGR R T 2007. [DOI: 10.1081/jlc-120013988] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
10
|
HIKI S, TOKESHI M, KAKUTA M, MAWATARI K, KIKUTANI Y, SATO K, HIBARA A, SHIMURA K, UCHIDA N, KITAMORI T. Highly Sensitive Detection of Non-Labeled Peptides Using UV Excitation Thermal Lens Microscope/Liquid Chromatography. BUNSEKI KAGAKU 2007. [DOI: 10.2116/bunsekikagaku.56.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
| | - Manabu TOKESHI
- Institute of Microchemical Technology
- Micro Chemistry Group, Special Research Laboratory for Optical Science, Kanagawa Academy of Science and Technology
| | - Masaya KAKUTA
- Institute of Microchemical Technology
- Micro Chemistry Group, Special Research Laboratory for Optical Science, Kanagawa Academy of Science and Technology
| | - Kazuma MAWATARI
- Micro Chemistry Group, Special Research Laboratory for Optical Science, Kanagawa Academy of Science and Technology
| | - Yoshikuni KIKUTANI
- Micro Chemistry Group, Special Research Laboratory for Optical Science, Kanagawa Academy of Science and Technology
| | - Kiichi SATO
- Micro Chemistry Group, Special Research Laboratory for Optical Science, Kanagawa Academy of Science and Technology
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo
| | - Akihide HIBARA
- Micro Chemistry Group, Special Research Laboratory for Optical Science, Kanagawa Academy of Science and Technology
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo
| | - Kiyohito SHIMURA
- Micro Chemistry Group, Special Research Laboratory for Optical Science, Kanagawa Academy of Science and Technology
| | - Naoyuki UCHIDA
- Graduate School of Bioresource Sciences, Nihon University
| | - Takehiko KITAMORI
- Micro Chemistry Group, Special Research Laboratory for Optical Science, Kanagawa Academy of Science and Technology
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo
| |
Collapse
|
11
|
Bendrysheva SN, Proskurnin MA, Pyell U, Faubel W. Sensitivity improvement in capillary electrophoresis using organo-aqueous separation buffers and thermal lens detection. Anal Bioanal Chem 2006; 385:1492-503. [PMID: 16865338 DOI: 10.1007/s00216-006-0602-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2006] [Revised: 05/31/2006] [Accepted: 06/08/2006] [Indexed: 10/24/2022]
Abstract
It is shown that organo-aqueous separation buffers show much promise when used in capillary electrophoresis separations with photothermal (thermal lens) detection systems. Acetonitrile-water and methanol-water mixtures were selected, as conventionally used in capillary electrophoresis. It is shown that, despite more sophisticated experimental conditions (significant heat outflow from the capillary body) and peak detection, the theoretical ratio of the thermal lens signal for a binary mixture to the thermal lens signal for an aqueous solution (or the corresponding ratio obtained experimentally under bulk batch conditions) can be used to predict the sensitivity of thermal lens detection in capillary electrophoresis. The limits of detection for 2-, 3-, and 4-nitrophenols selected as model compounds in 70% v/v acetonitrile separation buffers are 1 x 10(-6) M, 1 x 10(-6) M and 3 x 10(-7) M, respectively, and are therefore decreased by a factor of six compared to thermal lens detection in aqueous separation buffers. The overall increase in the thermal lens detection sensitivity in a 100% ACN buffer is a factor of 13.
Collapse
|
12
|
Dube S, Khumalo MT, Torto N, Nyati JA. Characterization of amino acids in silk sericin protein fromGonometa rufobrunnae by MEKC with phenyl isothiocyanate derivatization. J Sep Sci 2006; 29:1245-50. [PMID: 16833082 DOI: 10.1002/jssc.200600045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An MEKC method was developed for the separation and characterization of phenyl-isothiocyanate (PITC)-labeled amino acids derived from Gonometa rufobrunnae silkworm after microdialysis sample cleanup. The influence of the buffer and SDS concentration on the resolution of the amino acids was investigated. A buffer system consisting of 25 mM phosphate, 10 mM borate buffer at pH 9.00, and 70 mM SDS showed the best results, with 13 PITC-amino acid derivatives being resolved out of 15 possible amino acids that were under study. Microdialysis sampling demonstrated its efficiency as a sample cleanup technique. Sericin protein from G. rufobrunnae was found to be characterized by at least 11 positively identified amino acids. These included His, Tyr, Ser, Ala, Phe, Lys, Gly, Arg, Cys, Glu, and Asp. Leu/Met and Val/Thr were coeluting pairs and hence could not be positively confirmed.
Collapse
Affiliation(s)
- Simiso Dube
- Department of Applied Chemistry, National University of Science and Technology, P. O. Box AC 939, Ascot, Bulawayo, Zimbabwe.
| | | | | | | |
Collapse
|
13
|
van der Sneppen L, Wiskerke A, Ariese F, Gooijer C, Ubachs W. Improving the sensitivity of HPLC absorption detection by cavity ring-down spectroscopy in a liquid-only cavity. Anal Chim Acta 2006. [DOI: 10.1016/j.aca.2005.11.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
14
|
Proskurnin MA, Bendrysheva SN, Ragozina N, Heissler S, Faubel W, Pyell U. Optimization of instrumental parameters of a near-field thermal-lens detector for capillary electrophoresis. APPLIED SPECTROSCOPY 2005; 59:1470-9. [PMID: 16390585 DOI: 10.1366/000370205775142494] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The optical scheme of a near-field dual-beam mode-mismatched thermal-lens detector for capillary electrophoresis with a crossed-beam configuration employing a multimode HeCd laser (325 nm) as an excitation source was optimized. It is shown that a multimode laser can be successfully used as an excitation source in thermal lensing with minimal deviations in thermal responses from Gaussian excitation sources. An equation for diffraction thermal-lens theory for near-field measurements is deduced, and the experimental results agree with the deduced equation. The temperature rise in the capillary was estimated, and the exponential decrease of the signal with time for static conditions and low flow velocities was explained. The optimum configuration of the detector from the viewpoint of the maximum sensitivity and beam sizes was found. The detector provides a significant improvement in the detection limits for model compounds absorbing at 325 nm (nitrophenols) compared to the results obtained with a commercial absorbance detector operating at the same wavelength.
Collapse
Affiliation(s)
- Mikhail A Proskurnin
- M.V. Lomonosov Moscow State University, Chemistry Department, Vorob'evy Hills d. 1 str. 3 119992 GSP-3 Moscow, Russia.
| | | | | | | | | | | |
Collapse
|
15
|
Kato M, Sakai-Kato K, Toyo'oka T. Silica sol-gel monolithic materials and their use in a variety of applications. J Sep Sci 2005. [DOI: 10.1002/jssc.200500225] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
16
|
Ghaleb KA, Georges J. Photothermal spectrometry for detection in miniaturized systems: relevant features, strategies and recent applications. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2004; 60:2793-2801. [PMID: 15350914 DOI: 10.1016/j.saa.2003.12.048] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2003] [Accepted: 12/17/2003] [Indexed: 05/24/2023]
Abstract
There is a growing interest in using miniaturized analytical devices because they allow to execute the different steps of an analytical process within very short times and with drastic reduction in the amounts of solvents, reagents and samples. As for capillary electrophoresis, these systems require detectors which are sensitive, versatile and adaptable to very small detection volumes. In this respect, photothermal spectrometry which is complementary to fluorescence seems to be a promising detection method. This review describes the basic principle of photothermal spectrometry along with the related methods based on colinear-beam or crossed-beam configuration of the pump and probe lasers. Two experimental set ups especially designed for microfluidic systems as well as for capillary electrophoresis are described. Their characteristics and key features are discussed and the main applications are outlined.
Collapse
Affiliation(s)
- K Abbas Ghaleb
- Laboratoire des Sciences Analytiques, Université Claude Bernard-Lyon 1, 43 Boulevard du 11 Novembre 1918, Bâtiment CPE-308D, 69622 Villeurbanne Cedex, France
| | | |
Collapse
|
17
|
Chapter 14 Chromatography of amino acids and peptides. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/s0301-4770(04)80027-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
18
|
Jiskra J, Claessens HA, Cramers CA. Stationary and mobile phases in capillary electrochromatography (CEC). J Sep Sci 2003. [DOI: 10.1002/jssc.200301305] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
19
|
She Z, Sun Z, Wu L, Wu K, Sun S, Huang Z. Rapid method for the determination of amino acids in serum by capillary electrophoresis. J Chromatogr A 2002; 979:227-32. [PMID: 12498252 DOI: 10.1016/s0021-9673(02)01251-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A rapid method for the determination of amino acids in serum is presented. The derivatization of amino acids with 2,4-dinitrofluorobenzene was performed in 0.5 M sodium borate (pH 9.5). The complete separation of derivatives of 16 amino acids and an internal standard (D-norleucine) was achieved within 8 min by capillary zone electrophoresis. The running buffer consisted of 30 mM sodium tetraborate (pH 9.8)-isopropanol-30% Brij 35 (825:150:25, v/v). The capillary used had an internal diameter of 75 microm and an effective length of 300 mm. A voltage of 28 kV was applied. Temperature was maintained at 15 degrees C. Detection was 360 nm. The assay was linear from 10 to 700 microM. The minimal detection limit was 2.5-7.9 microM. The recovery of amino acids added to serum samples was 86.3-107.4%. Within-run precision was 2.8-10.3%, and between-run precision was 3.5-11.6%. The concentrations of amino acids in serum of 32 patients with chronic renal failure were measured. Among them, the levels of serine, isoleucine and valine were significantly lower than those of healthy volunteers (P<0.01), but the concentrations of cystine, tryptophan and phenylane were significantly higher than those of healthy volunteers (P<0.01). The result showed that the method could be used for determining amino acids in clinical practice and scientific research.
Collapse
Affiliation(s)
- Zuojun She
- Department of Clinical Chemistry, Anhui Provincial Center for Clinical Laboratory, 17 Lujiang Road, Hefei 230001, Anhui Province, China.
| | | | | | | | | | | |
Collapse
|
20
|
|
21
|
Svec F. Capillary electrochromatography: a rapidly emerging separation method. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2002; 76:1-47. [PMID: 12126266 DOI: 10.1007/3-540-45345-8_1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
This overview concerns the new chromatographic method--capillary electrochromatography (CEC)--that is recently receiving remarkable attention. The principles of this method based on a combination of electroosmotic flow and analyte-stationary phase interactions, CEC instrumentation, capillary column technology, separation conditions, and examples of a variety of applications are discussed in detail.
Collapse
Affiliation(s)
- Frantisek Svec
- Department of Chemistry, University of California, Berkeley 94720-1460, USA.
| |
Collapse
|
22
|
|
23
|
Shediac R, Ngola SM, Throckmorton DJ, Anex DS, Shepodd TJ, Singh AK. Reversed-phase electrochromatography of amino acids and peptides using porous polymer monoliths. J Chromatogr A 2001; 925:251-63. [PMID: 11519810 DOI: 10.1016/s0021-9673(01)01036-6] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Efficient and rapid separation of minute levels of amino acids and bioactive peptides is of significant importance in the emerging field of proteomics as well as in the clinical and pharmaceutical arena. We have developed novel UV-initiated acrylate-based porous polymer monoliths as stationary phases for capillary- and chip-electrochromatography of cationic, anionic, and neutral amino acids and peptides, followed by absorbance or laser-induced fluorescence detection. The rigid monoliths are cast-to-shape and are tunable for charge and hydrophobicity. For separations at low pH, monoliths containing quaternary amine moieties were used to achieve high electroosmotic flow, and for high pH separations monoliths with acidic sulfonic acid groups were employed. Efficient and reproducible separations of phenylthiohydantoin-labeled amino acids, native peptides, and amino acids and peptides labeled with naphthalene-2,3-dicarboxaldehyde (NDA) were achieved using both negatively- and positively-charged polymer monoliths in capillaries. Separation efficiencies in the range of 65,000-371,000 plates/m were obtained with capillary electrochromatography. Buffer composition and the degree of column hydrophobicity were studied systematically to optimize separations. The monoliths were also cast in the microchannels of glass chips and electrochromatographic separation followed by laser-induced fluorescence detection of three NDA-labeled bioactive peptides was obtained.
Collapse
Affiliation(s)
- R Shediac
- Chemical & Radiation Detection Laboratories, Sandia National Laboratories, Livermore, CA 94551-0969, USA
| | | | | | | | | | | |
Collapse
|
24
|
Kato M, Dulay MT, Bennett BD, Quirino JP, Zare RN. Photopolymerized sol-gel frits for packed columns in capillary electrochromatography. J Chromatogr A 2001; 924:187-95. [PMID: 11521865 DOI: 10.1016/s0021-9673(01)00772-5] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Porous sol-gel frits are fabricated in a capillary column by filling it with a solution of 3-(trimethoxysilyl)propyl methacrylate, hydrochloric acid, water, toluene (porogen), and a photoinitiator (Irgacure 1800) and exposing it to UV light at 365 nm for 5 min. The separation column (30 cm x 75 microm I.D.) contains between the inlet and outlet frits a 15-cm packed segment filled with 5-microm silica particles modified with the chiral compound (S)-N-3,5-dinitrobenzoyl-1-naphthylglycine. A detection window (1 mm long) is placed immediately after the outlet frit. To demonstrate the performance of this chiral separation column, mixtures of 16 different amino acids (three of which are not naturally occurring) derivatized with the fluorogenic reagent 4-fluoro-7-nitro-2,1,3-benzoxadiazole were separated by capillary chromatography. The enantiomeric separation of the column results in a resolution ranging from 1.21 to 8.29, and a plate height ranging from 8.7 to 39 microm.
Collapse
Affiliation(s)
- M Kato
- Department of Chemistry, Stanford University, CA 94305-5080, USA
| | | | | | | | | |
Collapse
|
25
|
Rozing GP, Dermaux A, Sandra P. Instrumentation for Capillary Electrochromatography. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s0301-4770(01)80074-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
|