Abstract
Solid-state Nuclear magnetic resonance (NMR) was used here to explore structural characteristics of samples to be subjected to matrix-assisted laser desorption/ionization (MALDI) and prepared without the use of any solvent. The analytical systems scrutinized in NMR were mixtures of a 2,5-dihydroxybenzoic acid (2,5-DHB) matrix and caesium fluoride (CsF), used as the cationization agent in synthetic polymer MALDI mass analysis, at different molar ratios (1:1, 5:1, and 10:1). Complementary information could be obtained from 13C, 133Cs, and 19F NMR spectra. Grinding the matrix together with the salt in the solid state was shown to induce a strong modification in the molecular organization within the MALDI sample. The evidenced mechano-induced reactions allow strong interactions between the matrix and the cation, up to the formation of a salt, and only occur in the presence of some water molecules. Addition of a poly(ethylene oxide) polymer as the analyte did not further modify the observed molecular organizations. Although relative matrix and salt concentrations in the scrutinized samples were unusual for MALDI analysis, mass spectra of good quality could be obtained and revealed that cation attachment on polymers during the MALDI process is not a matrix-independent event since a lower ionization efficiency was obtained from highly organized solid samples, mostly consisting of 2,5-DHB caesium salt species.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Montaudo, G.; Montaudo, M. S.; Samperi, F. Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry of Polymers (MALDI-MS). In Mass Spectrometry of Polymers; CRC Press: New York, 2002; pp 419–522.
Pasch, H.; Schrepp, W. Mass Spectrometry of Synthetic Polymers; Springer: New York, 2003.
Wallace, W. E.; Bauer, B. J.; Blair, W. R.; Flynn, K. M.; Gutman, C. M.; Kearsley, A. J. http://polymers.msel.nist.gov/maldirecipes/index.cfm.
Skelton, R.; Dubois, F.; Zenobi, R. A MALDI sample preparation method suitable for insoluble polymers. Anal. Chem. 2000, 72, 1707–1710.
Trimpin, S.; Rouhanipour, A.; Az, R.; Rader, H. J.; Mullen, K. New Aspects in Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry: A Universal Solvent-Free Sample Preparation. Rapid Commun. Mass Spectrom. 2001, 15, 1364–1373.
Doktycz, S. J.; Savickas, P. J.; Krueger, D. A. Matrix Sample Interactions in Ultraviolet Laser-Desorption of Proteins. Rapid Commun. Mass Spectrom. 1991, 5, 145–148.
Preston, L. M.; Murray, K. K.; Russell, D. H. Reproducibility and Quantitation of Matrix-Assisted Laser-Desorption Ionization Mass-Spectrometry—Effects of Nitrocellulose on Peptide Ion Yields. Biol. Mass Spectrom. 1993, 22, 544–550.
Chan, T. W. D.; Colburn, A. W.; Derrick, P. J.; Gardiner, D. J.; Bowden, M. Suppression of Matrix Ions in Ultraviolet-Laser Desorption-Scanning Electron-Microscopy and Raman-Spectroscopy of the Solid Samples. Org. Mass Spectrom. 1992, 27, 188–194.
Westman, A.; Huthfehre, T.; Demirev, P.; Sundqvist, B. U. R. Sample Morphology Effects in Matrix-Assisted Laser-Desorption Ionization Mass-Spectrometry of Proteins. J. Mass Spectrom. 1995, 30, 206–211.
Gusev, A. I.; Wilkinson, W. R.; Proctor, A.; Hercules, D. M. Improvement of Signal Reproducibility and Matrix/Co-Matrix Effects in MALDI Analysis. Anal. Chem. 1995, 67, 1034–1041.
Horneffer, V.; Reichelt, R.; Strupat, K. Protein Incorporation into MALDI-Matrix Crystals Investigated by High Resolution Field Emission Scanning Electron Microscopy. Int. J. Mass Spectrom. 2003, 226, 117–131.
Hanton, S. D.; Hyder, I. Z.; Stets, J. R.; Owens, K. G.; Blair, W. R.; Guttman, C. M.; Giuseppetti, A. A. Investigations of Electrospray Sample Deposition for Polymer MALDI Mass Spectrometry. J. Am. Soc. Mass Spectrom. 2004, 15, 168–179.
Horneffer, V.; Forsmann, A.; Strupat, K.; Hillenkamp, F.; Kubitscheck, U. Localization of Analyte Molecules in MALDI Preparations by Confocal Laser Scanning Microscopy. Anal. Chem. 2001, 73, 1016–1022.
Horneffer, V.; Strupat, K.; Hillenkamp, F. Localization of Noncovalent Complexes in MALDI Preparations by CLSM. J. Am. Soc. Mass Spectrom. 2006, 17, 1599–1604.
Hanton, S. D.; Clark, P. A. C.; Owens, K. G. Investigations of Matrix-Assisted Laser Desorption/Ionization Sample Preparation by Time-of-Flight Secondary Ion Mass Spectrometry. J. Am. Soc. Mass Spectrom. 1999, 10, 104–111.
Garden, R. W.; Sweedler, J. V. Heterogeneity Within MALDI Samples as Revealed by Mass Spectrometric Imaging. Anal. Chem. 2000, 72, 30–36.
Mele, A.; Malpezzi, L. Noncovalent Association Phenomena of 2,5-Dihydroxybenzoic Acid with Cyclic and Linear Oligosaccharides: A Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometric and X-ray Crystallographic Study. J. Am. Soc. Mass Spectrom. 2000, 11, 228–236.
Strupat, K.; Kampmeier, J.; Horneffer, V. Investigations of 2,5-DHB and Succinic Acid as Matrices for UV and IR MALDI: Part II: Crystallographic and Mass Spectrometric Analysis. Int. J. Mass Spectrom. 1997, 169, 43–50.
Hanton, S. D.; McEvoy, T. M.; Stets, J. R. Imaging the Morphology of Solvent-Free Prepared MALDI Samples. J. Am. Soc. Mass Spectrom. 2008, 19, 874–881.
Andrew, E. R. Magic Angle Spinning In Encyclopedia of NMR; Grant, D. M.; Harris, R. K., Eds., Wiley: Chichester, 1996; pp 2891–2901.
Schaefer, J.; Stejskal, E. O. C. −13 Nuclear Magnetic-Resonance of Polymers Spinning at Magic Angle. J. Am. Chem. Soc. 1976, 98, 1031–1032.
Sroka-Bartnicka, A.; Olejniczak, S.; Sochacki, M.; Biela, T.; Potrzebowski, M. J. Solid-State NMR Spectroscopy as a Tool Supporting Optimization of MALDI-TOF MS Analysis of Polylactides. J. Am. Soc. Mass Spectrom. 2009, 20, 67–72.
Spickermann, J.; Martin, K.; Rader, H. J.; Mullen, K.; Schlaad, H.; Muller, A. H. E.; Kruger, R. P. Quantitative Analysis of Broad Molecular Weight Distributions Obtained by Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry. Eur. Mass Spectrom. 1996, 2, 161–165.
Knochenmuss, R.; Lehmann, E.; Zenobi, R. Polymer Cationization in Matrix-Assisted Laser Desorption/Ionization. Eur. Mass Spectrom. 1998, 4, 421–426.
Massiot, D.; Fayon, F.; Capron, M.; King, I.; Le Calve, S.; Alonso, B.; Durand, J. O.; Bujoli, B.; Gan, Z. H.; Hoatson, G. Modeling One- and Two-Dimensional Solid-State NMR Spectra. Magn. Reson. Chem. 2002, 40, 70–76.
Gross, U.; Rudiger, S.; Grimmer, A. R.; Kemnitz, E. F. −19-NMR Solid State Investigations of Monovalent Alkali Metal Fluorides and Tetra-Alkylammonium Fluorides. J. Fluorine Chem. 2002, 115, 193–199.
Hayashi, S.; Hayamizu, K. Accurate Determination of NMR Chemical-Shifts in Alkali-Halides and Their Correlation with Structural Factors. Bull. Chem. Soc. Jpn. 1990, 63, 913–919.
Miller, J. M. Fluorine-19 Magic-Angle Spinning NMR. Progr. Nucl. Magn. Reson. Spectrosc. 1996, 28, 255–281.
Haisa, M.; Kashino, S.; Hanada, S. I.; Tanaka, K.; Okazaki, S.; Shibagaki, M. The Structures of 2-Hydroxy-5-Methylbenzoic Acid and Dimorphs of 2,5-Dihydroxybenzoic Acid. Acta Crystallogr. Sect. B Struct. Sci. 1982, 38, 1480–1485.
Asseid, F. M.; Miller, J. M.; Clark, J. H. FT-IR and Si-29, Al-27, and F-19 Mas NMR-Studies of the Adsorption of CdF2, ZnF2, and CuF2 onto Montmorillonite K10—Activity Towards Friedel-Crafts Alkylation. Can. J. Chem. 1992, 70, 2398–2404.
Wong, A.; Sham, S.; Wang, S. N.; Wu, G. A Solid-State Cs-133 Nuclear Magnetic Resonance and X-ray Crystallographic Study of Cesium Complexes with Macrocyclic Ligands. Can. J. Chem. 2000, 78, 975–985.
Wiesbrock, F.; Schmidbaur, H. Crystal Structures of Rubidium and Cesium Anthranilates and Salicylates. Inorg. Chem. 2003, 42, 7283–7289.
Claramunt, R. M.; Garcia, M. A.; Lopez, C.; Elguero, J. The Structure of 3,5-Dimethylpyrazole/Carboxylic Acids Co-Crystals. ARKIVOC. 2005, 91–101.
Fernandez-Bertran, J.; Reguera, E. Proton Transfer in the Solid State: Mechano-Chemical Reactions of Fluorides with Acidic Substances. Solid State Ionics. 1998, 112, 351–354.
Fernandez-Bertran, J.; Alvarez, J. C.; Reguera, E. Proton Transfer in the Solid State: Reactions of Organic Acids and Amines. Solid State Ionics. 1998, 106, 129–135.
Paneque, A.; Reguera, E.; Fernandez-Bertran, J.; Yee-Madeira, H. Mechano-Chemical Reactions of Fluorides with Hemin. J. Fluorine Chem. 2002, 113, 1–5.
Gerken, M.; Boatz, J. A.; Kornath, A.; Haiges, R.; Schneider, S.; Schroer, T.; Christe, K. O. The F-19 NMR shifts are not a measure for the nakedness of the fluoride anion. J. Fluorine Chem. 2002, 116, 49–58.
Dogruel, D.; Nelson, R. W.; Williams, P. The effects of matrix pH and cation availability on the matrix-assisted laser desorption ionization mass spectrometry of poly(methyl methacrylate). Rapid Commun. Mass Spectrom. 1996, 10, 801–804.
King, R. C.; Owens, K. G. Proceedings of the 43rd Annual Conference on Mass Spectrometry and Allied Topics; Atlanta, GA, 1995.
Author information
Authors and Affiliations
Corresponding authors
Additional information
Published online July 10, 2009
Electronic supplementary material
Rights and permissions
About this article
Cite this article
Pizzala, H., Barrère, C., Mazarin, M. et al. Solid state nuclear magnetic resonance as a tool to explore solvent-free MALDI samples. J Am Soc Mass Spectrom 20, 1906–1911 (2009). https://doi.org/10.1016/j.jasms.2009.06.021
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1016/j.jasms.2009.06.021