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Naito Y, Kotani M, Ohmura T. A novel laser desorption/ionization method using through hole porous alumina membranes. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2018; 32:1851-1858. [PMID: 30076645 PMCID: PMC6175246 DOI: 10.1002/rcm.8252] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 07/16/2018] [Accepted: 07/25/2018] [Indexed: 06/01/2023]
Abstract
RATIONALE A novel matrix-free laser desorption/ionization method based on porous alumina membranes was developed. The porous alumina membranes have a two-dimensional (2D) ordered structure consisting of closely aligned straight through holes of sub-micron in diameter that are amenable to mass production by industrial fabrication processes. METHODS Considering a balance between the ion generating efficiency and the mechanical strength of the membranes, the typical values for the hole diameter, open aperture ratio and membrane thickness were set to 200 nm, 50% and 5 μm, respectively. The membranes were coated with platinum on a single side that was exposed to the laser. Evaluation experiments were conducted on the feasibility of this membrane structure for an ionization method using a single peptide and mixed peptides and polyethylene glycol samples and a commercial matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometer in the positive ion mode. RESULTS Results showed a softness of ionization and no sweet spot nature. The capillary action of the through holes with very high aspect ratio enables several loading protocols including sample impregnation from the surface opposite to the laser exposure side. CONCLUSIONS The feasibility study indicates that the through hole porous alumina membranes have several advantages in terms of usefulness over the conventional surface-assisted laser desorption ionization (SALDI) methods. The proposed novel ionization method is termed Desorption Ionization Using Through Hole Alumina Membrane (DIUTHAME).
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Affiliation(s)
- Yasuhide Naito
- The Graduate School for the Creation of New Photonics Industries1955‐1 Kurematsu‐cho, Nishi‐kuHamamatsu431‐1202Japan
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Wu CY, Lee KC, Kuo YL, Chen YC. Revisiting the quantitative features of surface-assisted laser desorption/ionization mass spectrometric analysis. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2016; 374:rsta.2015.0379. [PMID: 27644973 PMCID: PMC5031644 DOI: 10.1098/rsta.2015.0379] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/23/2016] [Indexed: 06/06/2023]
Abstract
Surface-assisted laser desorption/ionization (SALDI) coupled with mass spectrometry (MS) is frequently used to analyse small organics owing to its clean background. Inorganic materials can be used as energy absorbers and the transfer medium to facilitate the desorption/ionization of analytes; thus, they are used as SALDI-assisting materials. Many studies have demonstrated the usefulness of SALDI-MS in quantitative analysis of small organics. However, some characteristics occurring in SALDI-MS require certain attention to ensure the reliability of the quantitative analysis results. The appearance of a coffee-ring effect in SALDI sample preparation is the primary factor that can affect quantitative SALDI-MS analysis results. However, to the best of our knowledge, there are no reports relating to quantitative SALDI-MS analysis that discuss or consider this effect. In this study, the coffee-ring effect is discussed using nanoparticles and nanostructured substrates as SALDI-assisting materials to show how this effect influences SALDI-MS analysis results. Potential solutions for overcoming the existing problems are also suggested.This article is part of the themed issue 'Quantitative mass spectrometry'.
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Affiliation(s)
- Ching-Yi Wu
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan
| | - Kai-Chieh Lee
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan
| | - Yen-Ling Kuo
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan
| | - Yu-Chie Chen
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan
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SALDI-TOF-MS analyses of small molecules (citric acid, dexasone, vitamins E and A) using TiO2 nanocrystals as substrates. Anal Bioanal Chem 2016; 408:7481-90. [DOI: 10.1007/s00216-016-9846-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 06/28/2016] [Accepted: 07/28/2016] [Indexed: 11/25/2022]
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Cegłowski M, Jasiecki S, Schroeder G. Laser desorption/ionization mass spectrometric analysis of folic acid, vancomycin and Triton® X-100 on variously functionalized carbon nanotubes. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2013; 27:2631-2638. [PMID: 24591024 DOI: 10.1002/rcm.6728] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 08/29/2013] [Accepted: 09/02/2013] [Indexed: 06/03/2023]
Abstract
RATIONALE Carbon nanotubes (CNTs) have been ascertained to constitute versatile assisting matrices for laser desorption/ionization mass spectrometric analysis of different molecules. The functionalization thereof can lead to obtaining laser desorption/ionization assisting surfaces that would allow the detection of molecules at lower concentration and produce spectra with a better signal-to-noise ratio. METHODS Pristine, -OH and -COOH functionalized multi-walled CNTs were obtained from commercial suppliers. Gallic or sinapinic acid was attached covalently to the CNT surfaces by forming an ester bond. Folic acid, vancomycin and Triton(®) X-100 were used as analytes to examine properties of these new assisting surfaces. Mass spectrometry analysis was conducted on a matrix-assisted laser desorption/ionization quadrupole time-of-flight (MALDIQTOF) mass spectrometer. RESULTS The functionalization of CNTs was confirmed with Fourier transform infrared (FTIR) spectroscopy. The obtained mass spectra revealed that all the assisting surfaces are capable of transferring energy to the analytes; moreover, the presence of carboxyl groups in the structures of CNTs highly enhances their ionization properties. Nevertheless, the presence of sinapinic acid on CNT surfaces does not increase their properties to absorb pulse laser energy. CONCLUSIONS The presented assisting surfaces are effective in LDI mass analysis of folic acid, vancomycin and Triton(®) X-100. The appropriate functionalization of CNTs can lead to the production of assisting surfaces that can become highly effective in the ionization of particular types of analytes.
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Affiliation(s)
- Michał Cegłowski
- Faculty of Chemistry, Adam Mickiewicz University in Poznan, Umultowska 89b, 61-614, Poznan, Poland
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Cegłowski M, Schroeder G. Laser desorption/ionization mass spectrometric analysis of surfactants on functionalized carbon nanotubes. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2013; 27:258-264. [PMID: 23239340 DOI: 10.1002/rcm.6448] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 10/19/2012] [Accepted: 10/21/2012] [Indexed: 06/01/2023]
Abstract
RATIONALE Recently, unmodified and carboxylated carbon nanotubes have been used as assisting surfaces laser desorption/ionization (LDI) in mass spectrometry. The functionalization of carbon nanotubes with organic compounds should lead to a gamut of other promising LDI-assisting surfaces. METHODS Carboxylated carbon nanotubes were functionalized with sinapinic acid either covalently or by creating an ionic macro-complex. Polyether-based surfactants were used as analytes to examine the properties of these new matrices. Mass spectrometric analysis was conducted on a LDI-quadrupole time-of-flight (QTOF) mass spectrometer. Carbon nanotube surfaces were deposited from suspension using the dried-droplet method. RESULTS The functionalization of the carbon nanotubes was confirmed with Fourier transform infrared (FTIR) spectroscopy. The usefulness of each material was examined with two poly(ethylene glycol) hexadecyl ether amphiphiles (Brij® 52 and Brij® 56) and a poly(ethylene glycol) monomethyl ether as analytes. Generally, the mass spectra obtained with carbon nanotubes covalently functionalized with sinapinic acid as a matrix had peaks with higher intensities than those obtained with carbon nanotubes functionalized by ionic macro-complex formation. CONCLUSIONS The presented new materials based on functionalized carbon nanotubes are effective in the LDI mass analysis of polyether amphiphiles and poly(ethylene glycol) monomethyl ether. This type of assisting surfaces can be highly modified by appropriate functionalization procedures.
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Affiliation(s)
- Michał Cegłowski
- Faculty of Chemistry, Adam Mickiewicz University in Poznan, Umultowska 89b, 61-614, Poznań, Poland.
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Ma R, Lu M, Ding L, Ju H, Cai Z. Surface-assisted laser desorption/ionization mass spectrometric detection of biomolecules by using functional single-walled carbon nanohorns as the matrix. Chemistry 2012; 19:102-8. [PMID: 23239539 DOI: 10.1002/chem.201202838] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Indexed: 01/21/2023]
Abstract
A surface-assisted laser desorption/ionization time-of-flight mass spectrometric (SALDI-TOF MS) method was developed for the analysis of small biomolecules by using functional single-walled carbon nanohorns (SWNHs) as matrix. The functional SWNHs could transfer energy to the analyte under laser irradiation for accelerating its desorption and ionization, which led to low matrix effect, avoided fragmentation of the analyte, and provided high salt tolerance. Biomolecules including amino acids, peptides, and fatty acids could successfully be analyzed with about 3- and 5-fold higher signals than those obtained using conventional matrix. By integrating the advantages of SWNHs and the recognition ability of aptamers, a selective approach was proposed for simultaneous capture, enrichment, ionization, and MS detection of adenosine triphosphate (ATP). This method showed a greatly improved detection limit (1.0 μM) for the analysis of ATP in complex biological samples. This newly designed protocol not only opened a new application of SWNHs, but also offered a new technique for selective MS analysis of biomolecules based on aptamer recognition systems.
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Affiliation(s)
- Rongna Ma
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China
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Dupré M, Cantel S, Durand JO, Martinez J, Enjalbal C. Silica nanoparticles pre-spotted onto target plate for laser desorption/ionization mass spectrometry analyses of peptides. Anal Chim Acta 2012; 741:47-57. [DOI: 10.1016/j.aca.2012.06.037] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2012] [Revised: 06/20/2012] [Accepted: 06/24/2012] [Indexed: 11/29/2022]
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Hsieh YT, Chen WT, Chang HT. Detection of Nucleoside Monophosphates through Surface-Assisted Laser, Desorption/Ionization Mass Spectrometry Using CTAB-Adsorbed Gold, Nanoparticles. J CHIN CHEM SOC-TAIP 2011. [DOI: 10.1002/jccs.201190119] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Spácil Z, Shariatgorji M, Amini N, Solich P, Ilag LL. Matrix-less laser desorption/ionisation mass spectrometry of polyphenols in red wine. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2009; 23:1834-1840. [PMID: 19444859 DOI: 10.1002/rcm.4062] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Matrix-assisted laser desorption/ionisation (MALDI) of small molecules is challenging and in most cases impossible due to interferences from matrix ions precluding analysis of molecules <300-500 Da. A common matrix such as ferulic acid belongs to an important class of compounds associated with antioxidant activity. If the shared phenolic structure is related to the propensity as an active MALDI matrix then it follows that direct laser desorption/ionisation should be possible for polyphenols. Indeed matrix-less laser desorption/ionisation mass spectrometry is achieved whereby the analyte functions as a matrix and was used to monitor low molecular weight compounds in wine samples. Sensitivity ranging from 0.12-87 pmol/spot was achieved for eight phenolic acids (4-coumaric, 4-hydroxybenzoic, caffeic, ferulic, gallic, protocatechuic, syringic, vanillic) and 0.02 pmol/spot for trans-resveratrol. Additionally, 4-coumaric, 4-hydroxybenzoic, caffeic, ferulic, gallic, syringic, vanillic acids and trans-resveratrol were identified in wine samples using accurate mass measurements consistent with reported profiles based on liquid chromatography (LC)/MS. Minimal sample pre-treatment make the technique potentially appropriate for fingerprinting, screening and quality control of wine samples.
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Affiliation(s)
- Zdenek Spácil
- Department of Analytical Chemistry, Faculty of Pharmacy, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Kralove, Czech Republic
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Lo CY, Lin JY, Chen WY, Chen CT, Chen YC. Surface-assisted laser desorption/ionization mass spectrometry on titania nanotube arrays. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2008; 19:1014-1020. [PMID: 18487059 DOI: 10.1016/j.jasms.2008.04.025] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2007] [Revised: 04/23/2008] [Accepted: 04/23/2008] [Indexed: 05/26/2023]
Abstract
Titania nanotube arrays (NTA) generated from anodizing processes are tested as the substrate for surface-assisted laser desorption/ionization mass spectrometry (SALDI MS). The background generated from titania NTA is very low, making the approach suitable for the analysis of small molecules. The upper detectable mass is approximately 29 kDa. Homogeneous sample deposition leads to good shot-to-shot reproducibility and suitability for quantitative analysis. Additionally, phosphopeptides can be selectively trapped on the titania NTA substrate, as illustrated by simply depositing a tryptic digest of beta-casein followed by titania NTA SALDI MS analysis. The detection limit for small organics and peptides is in low fmol.
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Affiliation(s)
- Chun-Yuan Lo
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu, Taiwan
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Chiu Y, Chen Y. Carboxylate‐Functionalized Iron Oxide Nanoparticles in Surface‐Assisted Laser Desorption/Ionization Mass Spectrometry for the Analysis of Small Biomolecules. ANAL LETT 2008. [DOI: 10.1080/00032710701792653] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Lee KH, Chiang CK, Lin ZH, Chang HT. Determining enediol compounds in tea using surface-assisted laser desorption/ionization mass spectrometry with titanium dioxide nanoparticle matrices. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2007; 21:2023-30. [PMID: 17534856 DOI: 10.1002/rcm.3058] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
We describe the use of titanium dioxide nanoparticles (TiO2 NPs) as selective probes and matrices for the determination of catechins using surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). The interactions between the enediol compounds and TiO2 NPs were evident by the change in color of the TiO2 NP solution from milky white to orange. Through these interactions, the TiO2 NPs could be used to concentrate enediol compounds, including catechins and ascorbic acid. The limits of detection (LODs) for three catechins--catechin, (-)-epigallocatechin, and (-)-epigallocatechin gallate--at a signal-to-noise ratio of 3 were 0.45, 1.85 and 0.65 microM, respectively. The TiO2 NP matrices provide a number of advantages over conventional organic matrices (e.g. 2',4',6'-trihydroxyacetophenone), including ease of sample preparation, less background noise in the low-mass region, and high repeatability. The applicability of this method was confirmed through the high reproducibility of the determination of the two catechins in tea samples that had not been subjected to any sample preparation procedures (shot-to-shot variation: <10%).
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Affiliation(s)
- Kun-Hong Lee
- Department of Chemistry, National Taiwan University, Taipei, Taiwan
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Ren SF, Guo YL. Oxidized carbon nanotubes as matrix for matrix-assisted laser desorption/ionization time-of-flight mass spectrometric analysis of biomolecules. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2005; 19:255-260. [PMID: 15609365 DOI: 10.1002/rcm.1779] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Oxidized carbon nanotubes (CNTs), which can form a stable homogeneous suspension in water close to a solution phase, were synthesized and used for matrix-assisted desorption/ionization mass spectrometric (MALDI-MS) analysis of biomolecules. Infrared (IR) spectra, transmission electron microscopy (TEM) and particle size analysis were used for the characterization of the oxidized CNTs. The results indicate that the physical structure of the CNTs was not damaged, but carboxylate groups were introduced onto the surface of the CNTs. In addition, impurities including amorphous carbon, which is one of the main reasons for ion source contamination, were destroyed by the oxidization. The carboxyl groups on the oxidized surface of the CNTs can not only provide an additional proton source, but can also increase the surface polarity and solubility of the CNTs, making it easier to manipulate which is important for MALDI analysis of some biomolecules, especially larger peptides and proteins. The oxidized CNTs were successfully applied to the analysis of neutral oligosaccharides, peptides, and insulin, and thus promise to be an efficient matrix for MALDI-MS analysis of biomolecules.
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Affiliation(s)
- Shi-Fang Ren
- Shanghai Mass Spectrometry Center, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, P.R. China
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Chen WY, Wang LS, Chiu HT, Chen YC, Lee CY. Carbon nanotubes as affinity probes for peptides and proteins in MALDI MS analysis. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2004; 15:1629-1635. [PMID: 15519230 DOI: 10.1016/j.jasms.2004.08.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2004] [Revised: 08/02/2004] [Accepted: 08/02/2004] [Indexed: 05/24/2023]
Abstract
Recently, carbon nanotubes (CNTs) have been reported to be an effective MALDI matrix for small molecules (Anal. Chem.2003, 75, 6191). In a somewhat related study, we have employed CNTs produced by using NaH-treated anodic aluminum oxide (Na@AAO) as a reactive template as the assisting matrix for MALDI analysis upon the addition of high concentrations of citrate buffer. Our results indicate that the mass range can be extended to ca. 12,000 Da and that alkali metal adducts of analytes are effectively reduced. Furthermore, we have employed citric acid-treated CNTs as affinity probes to selectively concentrate traces of analytes from aqueous solutions. High concentrations of salts and surfactants in the sample solutions are also tolerated. This approach is very suitable for the MALDI analysis of small proteins, peptides, and protein enzymatic digest products.
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Affiliation(s)
- Wei-Yu Chen
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan
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Hoang TT, Chen Y, May SW, Browner RF. Analysis of Organoselenium Compounds in Human Urine Using Active Carbon and Chemically Modified Silica Sol−Gel Surface-Assisted Laser Desorption/Ionization High-Resolution Time-of-Flight Mass Spectrometry. Anal Chem 2004; 76:2062-70. [PMID: 15053672 DOI: 10.1021/ac020707z] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Laser desorption/ionization time-of-flight mass spectra of three thermally labile low molecular weight organoselenium compounds (selenomethionine, selenoethionine, trimethylselenonium iodide) in human urine matrix have been obtained by using surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). Four active layers, active carbon, silica sol-gel, and silica sol-gel impregnated with crown ether and with active carbon, were deposited on three different support substrates: (i) microscope slide coverslips; (ii) Al foil; and (iii) Cu tapes. Primarily protonated molecular ions and alkali metal adducts were observed in the mass spectra. A mixed-silica sol-gel and active carbon substrate active layer gave the best signal response for all compounds. Sol-gel substrates offered very clean backgrounds compared to the pure active carbon layers; however, the mass spectral signal intensities acquired were substantially lower for the sol-gel surfaces than those of the pure active carbon under the same conditions. Cu tape and Al foil support materials gave strong mass spectra of molecular ions and alkali metal molecular ion adducts, with lower Na and K adducts found with the Cu tape than with Al foil. Glass coverslips gave no response under all experimental conditions examined. Aerosol deposition was used to prepare SALDI substrates to avoid the localized "sweet spot" phenomenon encountered in conventional SALDI substrate preparation. Various nebulizers were examined and found to be effective in producing SALDI films with controlled and reproducible thicknesses. We were able to obtain exact mass identification of all three selenium species by high-resolution TOF-MS. To the best of our knowledge, this is the first time low molecular weight organoselenium compounds have been identified by SALDI-high-resolution TOF-MS.
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Affiliation(s)
- Tiffany T Hoang
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0400, USA
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Cristoni S, Bernardi LR. Development of new methodologies for the mass spectrometry study of bioorganic macromolecules. MASS SPECTROMETRY REVIEWS 2003; 22:369-406. [PMID: 14528493 DOI: 10.1002/mas.10062] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In recent years, mass spectrometry has been increasingly used for the analysis of various macromolecules of biological, biomedical, and biochemical interest. This increase has been made possible by two key developments: the advent of electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI) sources. The two new techniques produce a significant increase in mass range and in sensitivity that led to the development of new applications and of new analyzer designs, software, and robotics. This review, apart from the description of the status of mass spectrometry in the analysis of bioorganic macromolecules, is mainly devoted to the illustration of the more recent promising techniques and on their possible future evolution.
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Affiliation(s)
- Simone Cristoni
- Università degli Studi di Milano, Centro Interdisciplinare Studi Bio-molecolari e Applicazioni Industriali CISI, Via Fratelli Cervi 93, 20090 Segrate Milano, Italy.
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Wu JY, Chen YC. A novel approach of combining thin-layer chromatography with surface-assisted laser desorption/ionization (SALDI) time-of-flight mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2002; 37:85-90. [PMID: 11813315 DOI: 10.1002/jms.264] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A novel means of combining thin-layer chromatography (TLC) with laser desorption/ionization mass spectrometry using a liquid matrix is proposed. Surface-assisted laser desorption/ionization (SALDI) mass spectrometry, which uses a mixture of a micrometer-sized carbon powder (graphite or activated carbon, the SALDI solid) and 15% sucrose/glycerol, dissolved in an equal volume of methanol (SALDI liquid) as a SALDI matrix, is used for laser desorption mass analysis. The ablation of carbon powder from a pencil drawing was used as an alternative to the SALDI solid. The liquid matrix resembled that used in a conventional SALDI matrix system. A line was drawn before separation with a pencil on the track of the sample developed on the TLC plate. After TLC separation, approximately 0.1 microl of SALDI liquid was directly applied to the chromatographic spots on the TLC plate. Porphyrins were used to demonstrate this combination owing to the visible colors of this type of compound. The analyte signal can be easily detected by irradiating the laser along the pencil line on the TLC plate. An additive, p-toluenesulfonic acid, is added to the SALDI liquid to enhance the signal's intensity. This additive dramatically improves the signal-to-noise ratio. A detection limit of approximately 500 pg is demonstrated for porphines, which is 50 times better than that corresponding to conventional TLC SALDI.
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Affiliation(s)
- Jia-Yi Wu
- Institute of Toxicology, Tzu Chi University, Hualien 970, Taiwan
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Alimpiev S, Nikiforov S, Karavanskii V, Minton T, Sunner J. On the mechanism of laser-induced desorption–ionization of organic compounds from etched silicon and carbon surfaces. J Chem Phys 2001. [DOI: 10.1063/1.1381531] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Chen YC, Sun MC. Determination of trace quaternary ammonium surfactants in water by combining solid-phase extraction with surface-assisted laser desorption/ionization mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2001; 15:2521-2525. [PMID: 11746926 DOI: 10.1002/rcm.534] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This study demonstrates the feasibility of combining solid-phase extraction (SPE) with surface-assisted laser desorption/ionization (SALDI) mass spectrometry to determine trace quaternary ammonium surfactants in water. The trace surfactants in water were directly concentrated on the surface of activated carbon sorbent in SPE. The activated carbon sorbent was then mixed with the SALDI liquid for SALDI analysis. No SPE elution procedure was necessary. Experimental results indicate that the surfactants with longer chain alkyl groups exhibit higher sensitivities than those with shorter chain alkyl groups in SPE-SALDI analysis. The detection limit for hexadecyltrimethylammonium bromide is around 10 ppt in SPE-SALDI analysis by sampling 100 mL of aqueous solution, while that of tetradecyltrimethylammonium bromide is about 100 ppt. The detection limit for decyltrimethylammonium bromide and dodecyltrimethylammonium bromide is in the low-ppb range.
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Affiliation(s)
- Y C Chen
- Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan.
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Current literature in mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2001; 36:107-118. [PMID: 11180652 DOI: 10.1002/1096-9888(200101)36:1<107::aid-jms88>3.0.co;2-q] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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