Selective Gas-Phase Mass Tagging via Ion/Molecule Reactions Combined with Single Analyzer Neutral Loss Scans to Probe Pharmaceutical Mixtures

  • Dalton T. Snyder
  • Lucas J. Szalwinski
  • Alice L. Pilo
  • Nina K. Jarrah
  • R. Graham CooksEmail author
Focus: Ion Mobility Spectrometry (IMS): Research Article


We have demonstrated the use of a simple single ion trap mass spectrometer to identify classes of compounds as well as individual components in complex mixtures. First, a neutral reagent was used to mass tag oxygen-containing analytes using a gas-phase ion/molecule reaction. Then, a neutral loss scan was used to indicate the carboxylic acids. The lack of unit mass selectivity in the neutral loss scan required subsequent product ion scans to confirm the presence and identity of the individual carboxylic acids. The neutral loss scan technique reduced the number of data-dependent MS/MS scans required to confirm identification of signals as protonated carboxylic acids. The method was demonstrated on neat mixtures of standard carboxylic acids as well as on solutions of relevant pharmaceutical tablets and may be generalizable to other ion/molecule reactions.


Ion/molecule reaction Linear ion trap Neutral loss scan Carboxylic acid 



The authors acknowledge funding from Merck & Co., Inc. and from NASA Planetary Sciences Division, Science Mission Directorate (NNX16AJ25G). This work was also funded by a NASA Space Technology Research Fellowship (DTS). Ryan Hilger and Mark Carlsen (Jonathan Amy Facility for Chemical Instrumentation) are thanked for modifications to the LTQ instrument for orthogonal double resonance capabilities. The authors finally thank Dr. Joann Max (Eli Lilly) for help with ion/molecule reactions and Rob Schrader for the table of contents graphic.

Supplementary material

13361_2019_2149_MOESM1_ESM.docx (58 kb)
ESM 1 (DOCX 58 kb)


  1. 1.
    Carroll, D.I., Dzidic, I., Stillwell, R.N., Haegele, K.D., Horning, E.C.: Atmospheric pressure ionization mass spectrometry. Corona discharge ion source for use in a liquid chromatograph-mass spectrometer-computer analytical system. Anal. Chem. 47, 2369–2373 (1975)CrossRefGoogle Scholar
  2. 2.
    Horning, E.C., Carroll, D.I., Dzidic, I., Haegele, K.D., Horning, M.G., Stillwell, R.N.: Liquid chromatograph—mass spectrometer—computer analytical systems: a continuous-flow system based on atmospheric pressure ionization mass spectrometry. J. Chromatogr. A. 99, 13–21 (1974)CrossRefGoogle Scholar
  3. 3.
    Na, N., Zhao, M., Zhang, S., Yang, C., Zhang, X.: Development of a dielectric barrier discharge ion source for ambient mass spectrometry. J. Am. Soc. Mass Spectrom. 18, 1859–1862 (2007)CrossRefGoogle Scholar
  4. 4.
    Harper, J.D., Charipar, N.A., Mulligan, C.C., Zhang, X., Cooks, R.G., Ouyang, Z.: Low-temperature plasma probe for ambient desorption ionization. Anal. Chem. 80, 9097–9104 (2008)CrossRefGoogle Scholar
  5. 5.
    Kumano, S., Sugiyama, M., Yamada, M., Nishimura, K., Hasegawa, H., Morokuma, H., Inoue, H., Hashimoto, Y.: Development of a portable mass spectrometer characterized by discontinuous sample gas introduction, a low-pressure dielectric barrier discharge ionization source, and a vacuumed headspace technique. Anal. Chem. 85, 5033–5039 (2013)CrossRefGoogle Scholar
  6. 6.
    Klute, F.D., Michels, A., Schutz, A., Vadla, C., Horvatic, V., Franzke, J.: Capillary dielectric barrier discharge: transition from soft ionization to dissociative plasma. Anal. Chem. 88, 4701–4705 (2016)CrossRefGoogle Scholar
  7. 7.
    Jjunju, F.P., Maher, S., Li, A., Badu-Tawiah, A.K., Taylor, S., Cooks, R.G.: Analysis of polycyclic aromatic hydrocarbons using desorption atmospheric pressure chemical ionization coupled to a portable mass spectrometer. J. Am. Soc. Mass Spectrom. 26, 271–280 (2015)CrossRefGoogle Scholar
  8. 8.
    Harris, G.A., Nyadong, L., Fernandez, F.M.: Recent developments in ambient ionization techniques for analytical mass spectrometry. Analyst. 133, 1297–1301 (2008)CrossRefGoogle Scholar
  9. 9.
    Munson, M.S., Field, F.-H.: Chemical ionization mass spectrometry. I. General introduction. J. Am. Chem. Soc. 88, 2621–2630 (1966)CrossRefGoogle Scholar
  10. 10.
    Gronert, S.: Mass spectrometric studies of organic ion/molecule reactions. Chem. Rev. 101, 329–360 (2001)CrossRefGoogle Scholar
  11. 11.
    Gronert, S.: Quadrupole ion trap studies of fundamental organic reactions. Mass Spectrom. Rev. 24, 100–120 (2004)CrossRefGoogle Scholar
  12. 12.
    Osburn, S., Ryzhov, V.: Ion–molecule reactions: analytical and structural tool. Anal. Chem. 85, 769–778 (2013)CrossRefGoogle Scholar
  13. 13.
    Leavell, M.D., Kruppa, G.H., Leary, J.A.: Analysis of phosphate position in hexose monosaccharides using ion−molecule reactions and SORI-CID on an FT-ICR mass spectrometer. Anal. Chem. 74, 2608–2611 (2002)CrossRefGoogle Scholar
  14. 14.
    Watkins, M.A., Winger, B.E., Shea, R.C., Kenttämaa, H.I.: Ion−molecule reactions for the characterization of polyols and polyol mixtures by ESI/FT-ICR mass spectrometry. Anal. Chem. 77, 1385–1392 (2005)CrossRefGoogle Scholar
  15. 15.
    Somuramasami, J., Duan, P., Watkins, M.A., Winger, B.E., Kenttamaa, H.I.: Ion–molecule reactions of trimethylborate allow the mass spectrometric identification and counting of functional groups in protonated bifunctional oxygen-containing compounds and polyols. Int. J. Mass Spectrom. 265, 359–371 (2007)CrossRefGoogle Scholar
  16. 16.
    Habicht, S.C., Vinueza, N.R., Archibold, E.F., Duan, P., Kenttämaa, H.I.: Identification of the carboxylic acid functionality by using electrospray ionization and ion−molecule reactions in a modified linear quadrupole ion trap mass spectrometer. Anal. Chem. 80, 3416–3421 (2008)CrossRefGoogle Scholar
  17. 17.
    Habicht, S.C., Vinueza, N.R., Amundson, L.M., Kenttamaa, H.I.: Comparison of functional group selective ion-molecule reactions of trimethyl borate in different ion trap mass spectrometers. J. Am. Soc. Mass Spectrom. 22, 520–530 (2011)CrossRefGoogle Scholar
  18. 18.
    Eismin, R.J., Fu, M., Yem, S., Widjaja, F., Kenttämaa, H.I.: Identification of epoxide functionalities in protonated monofunctional analytes by using ion/molecule reactions and collision-activated dissociation in different ion trap tandem mass spectrometers. J. Am. Soc. Mass Spectrom. 23, 12–22 (2012)CrossRefGoogle Scholar
  19. 19.
    Kong, J.Y., Yu, Z., Easton, M.W., Niyonsaba, E., Ma, X., Yerabolu, R., Sheng, H., Jarrell, T.M., Zhang, Z., Ghosh, A.K., Kenttämaa, H.I.: Differentiating isomeric deprotonated glucuronide drug metabolites via ion/molecule reactions in tandem mass spectrometry. Anal. Chem. 90, 9426–9433 (2018)CrossRefGoogle Scholar
  20. 20.
    Grigorean, G., Lebrilla, C.B.: Enantiomeric analysis of pharmaceutical compounds by ion/molecule reactions. Anal. Chem. 73, 1684–1691 (2001)CrossRefGoogle Scholar
  21. 21.
    Lennon, J.D., Cole, S.P., Glish, G.L.: Ion/molecule reactions to chemically deconvolute the electrospray ionization mass spectra of synthetic polymers. Anal. Chem. 78, 8472–8476 (2006)CrossRefGoogle Scholar
  22. 22.
    Henion, J.D., Kao, J.-L., Nixon, W.B., Bursey, M.M.: Analytical ion cyclotron resonance spectrometry. Increased discrimination between stereoisomers by ion-molecule reactions with 1,2-dicyclopropylethanedione. Anal. Chem. 47, 689–692 (1975)CrossRefGoogle Scholar
  23. 23.
    Thomas, M.C., Mitchell, T.W., Harman, D.G., Deeley, J.M., Nealon, J.R., Blanksby, S.J.: Ozone-induced dissociation: elucidation of double bond position within mass-selected lipid ions. Anal. Chem. 80, 303–311 (2008)CrossRefGoogle Scholar
  24. 24.
    Wyttenbach, T., Bowers, M.T.: Gas phase conformations of biological molecules: the hydrogen/deuterium exchange mechanism. J. Am. Soc. Mass Spectrom. 10, 9–14 (1999)CrossRefGoogle Scholar
  25. 25.
    Watkins, M.A., WeWora, D.V., Li, S., Winger, B.E., Kenttämaa, H.I.: Compound screening for the presence of the primary N-oxide functionality via ion−molecule reactions in a mass spectrometer. Anal. Chem. 77, 5311–5316 (2005)CrossRefGoogle Scholar
  26. 26.
    Yerabolu, R., Kong, J., Easton, M., Kotha, R.R., Max, J., Sheng, H., Zhang, M., Gu, C., Kenttämaa, H.I.: Identification of protonated sulfone and aromatic carboxylic acid functionalities in organic molecules by using ion–molecule reactions followed by collisionally activated dissociation in a linear quadrupole ion trap mass spectrometer. Anal. Chem. 89, 7398–7405 (2017)CrossRefGoogle Scholar
  27. 27.
    Zhu, H., Ma, X., Kong, J.Y., Zhang, M., Kenttämaa, H.I.: Identification of carboxylate, phosphate, and phenoxide functionalities in deprotonated molecules related to drug metabolites via ion–molecule reactions with water and diethylhydroxyborane. J. Am. Soc. Mass Spectrom. 28, 2189–2200 (2017)CrossRefGoogle Scholar
  28. 28.
    Zhu, H., Max, J.P., Marcum, C.L., Luo, H., Abu-Omar, M.M., Kenttämaa, H.I.: Identification of the phenol functionality in deprotonated monomeric and dimeric lignin degradation products via tandem mass spectrometry based on ion–molecule reactions with diethylmethoxyborane. J. Am. Soc. Mass Spectrom. 27, 1813–1823 (2016)CrossRefGoogle Scholar
  29. 29.
    Sheng, H., Tang, W., Yerabolu, R., Max, J., Kotha, R.R., Riedeman, J.S., Nash, J.J., Zhang, M., Kenttämaa, H.I.: Identification of N-oxide and sulfoxide functionalities in protonated drug metabolites by using ion–molecule reactions followed by collisionally activated dissociation in a linear quadrupole ion trap mass spectrometer. J. Organomet. Chem. 81, 575–586 (2016)CrossRefGoogle Scholar
  30. 30.
    Ouyang, Z., Noll, R.J., Cooks, R.G.: Handheld miniature ion trap mass spectrometers. Anal. Chem. 81, 2421–2425 (2009)CrossRefGoogle Scholar
  31. 31.
    Ouyang, Z., Cooks, R.G.: Miniature mass spectrometers. Annu. Rev. Anal. Chem. 2, 187–214 (2009)CrossRefGoogle Scholar
  32. 32.
    Snyder, D.T., Pulliam, C.J., Ouyang, Z., Cooks, R.G.: Miniature and fieldable mass spectrometers: recent advances. Anal. Chem. 88, 2–29 (2016)CrossRefGoogle Scholar
  33. 33.
    Snyder, D.T., Cooks, R.G.: Single analyzer precursor ion scans in a linear quadrupole ion trap using orthogonal double resonance excitation. J. Am. Soc. Mass Spectrom. 28, 1929–1938 (2017)CrossRefGoogle Scholar
  34. 34.
    Snyder, D.T., Cooks, R.G.: Single analyzer neutral loss scans in a linear quadrupole ion trap using orthogonal double resonance excitation. Anal. Chem. 89, 8148–8155 (2017)CrossRefGoogle Scholar
  35. 35.
    Snyder, D.T., Pulliam, C.J., Cooks, R.G.: Linear mass scans in quadrupole ion traps using the inverse Mathieu q scan. Rapid Commun. Mass Spectrom. 30, 2369–2378 (2016)CrossRefGoogle Scholar
  36. 36.
    Kempen, E.C., Brodbelt, J.: Use of trimethyl borate as a chemical ionization reagent for the analysis of biologically active molecules. J. Mass Spectrom. 32, 846–854 (1997)CrossRefGoogle Scholar
  37. 37.
    Suming, H., Yaozu, C., Longfei, J., Shuman, X.: Stereochemical effects in mass spectrometry: 2—chemical ionization mass spectra of some cyclic glycols and mono-and di-saccharides using trimethyl borate as reagent gas. Org. Mass Spectrom. 20, 719–723 (1985)CrossRefGoogle Scholar
  38. 38.
    Gronert, S., Richard, A.: Gas phase reactions of trimethyl borate with phosphates and their non-covalent complexes. J. Am. Soc. Mass Spectrom. 13, 1088–1098 (2002)CrossRefGoogle Scholar
  39. 39.
    Leavell, M., Leary, J.A.: Probing isomeric differences of phosphorylated carbohydrates through the use of ion/molecule reactions and FT-ICR MS. J. Am. Soc. Mass Spectrom. 14, 323–331 (2003)CrossRefGoogle Scholar
  40. 40.
    Gao, H., Petzold, C.J., Leavell, M.D., Leary, J.A.: Investigation of ion/molecule reactions as a quantification method for phosphorylated positional isomers: an FT-ICR approach. J. Am. Soc. Mass Spectrom. 14, 916–924 (2003)CrossRefGoogle Scholar
  41. 41.
    Piatkivskyi, A., Pyatkivskyy, Y., Hurt, M., Ryzhov, V.: Utilisation of gas-phase ion—molecule reactions for differentiation between phospho- and sulfocarbohydrates. Eur. J. Mass Spectrom. 20, 177–183 (2014)CrossRefGoogle Scholar
  42. 42.
    Snyder, D.T., Szalwinski, L.J., Hilger, R.T., Cooks, R.G.: Implementation of precursor and neutral loss scans on a miniature ion trap mass spectrometers and performance comparison to a benchtop linear ion trap. J. Am. Soc. Mass Spectrom. 29, 1355–1364 (2018)CrossRefGoogle Scholar
  43. 43.
    Snyder, D.T., Szalwinski, L.J., Schrader, R., Pirro, V., Hilger, R.T., Cooks, R.G.: Precursor and neutral loss scans in an rf scanning linear quadrupole ion trap. J. Am. Soc. Mass Spectrom. 29, 1345–1354 (2018)CrossRefGoogle Scholar
  44. 44.
    Riter, L.S., Meurer, E.C., Handberg, E.S., Laughlin, B.C., Chen, H., Patterson, G.E., Eberlin, M.N., Cooks, R.G.: Ion/molecule reactions performed in a miniature cylindrical ion trap mass spectrometer. Analyst. 128, 1112 (2003)CrossRefGoogle Scholar
  45. 45.
    Chen, H., Xu, R., Chen, H., Cooks, R.G., Ouyang, Z.: Ion/molecule reactions in a miniature RIT mass spectrometer. J. Mass Spectrom. 40, 1403–1411 (2005)CrossRefGoogle Scholar

Copyright information

© American Society for Mass Spectrometry 2019

Authors and Affiliations

  1. 1.Department of ChemistryPurdue UniversityWest LafayetteUSA
  2. 2.Analytical Research and DevelopmentMerck & Co., Inc.RahwayUSA

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