Skip to main content
SpringerLink
Log in

Effect of Mobile Phase on Electrospray Ionization Efficiency

  • Research Article
  • Published:
Journal of The American Society for Mass Spectrometry

Abstract

Electrospray (ESI) ionization efficiencies (IE) of a set of 10 compounds differing by chemical nature, extent of ionization in solution (basicity), and by hydrophobicity (tetrapropylammonium and tetraethylammonium ion, triethylamine, 1-naphthylamine, N,N-dimethylaniline, diphenylphthalate, dimethylphtahalate, piperidine, pyrrolidine, pyridine) have been measured in seven mobile phases (three acetonitrile percentages 20%, 50%, and 80%, and three different pH-adjusting additives, 0.1% formic acid, 1 mM ammonia, pH 5.0 buffer combination) using the relative measurement method. MS parameters were optimized separately for each ion. The resulting relative IE data were converted into comparable logIE values by anchoring them to the logIE of tetrapropylammonium ion taking into account the differences of ionization in different solvents and thereby making the logIE values of the compounds comparable across solvents. The following conclusions were made from analysis of the data. The compounds with pK a values in the range of the solution pH values displayed higher IE at lower pH. The sensitivity of IE towards pH depends on hydrophobicity being very strong with pyridine, weaker with N,N-dimethylaniline, and weakest with 1-naphthylamine. IEs of tetraalkylammonium ions and triethylamine were expectedly insensitive towards solution pH. Surprisingly high IEs of phthalate esters were observed. The differences in solutions with different acetonitrile content and similar pH were smaller compared with the pH effects. These results highlight the importance of hydrophobicity in electrospray and demonstrate that high hydrophobicity can sometimes successfully compensate for low basicity.

ᅟ

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Figure 1
Figure 2

Similar content being viewed by others

References

  1. Cech, N.B., Enke, C.G.: Practical implications of some recent studies in electrospray ionization fundamentals. Mass Spectrom. Rev. 20, 362–387 (2001)

    Article  CAS  Google Scholar 

  2. Kebarle, P., Tang, L.: From ions in solution to ions in the gas phase. Anal. Chem. 65, 972–986 (1993)

    Google Scholar 

  3. Chalcraft, K.R., Lee, R., Mills, C., Britz-McKibbin, P.: Virtual quantification of metabolites by capillary electrophoresis-electrospray ionization-mass spectrometry: predicting ionization efficiency without chemical standards. Anal. Chem. 81, 2506–2515 (2009)

    Article  CAS  Google Scholar 

  4. Ehrmann, B., Henriksen, T., Cech, N.B.: Relative importance of basicity in the gas phase and in solution for determining selectivity in electrospray ionization mass spectrometry. J. Am. Soc. Mass Spectrom. 19, 719–728 (2008)

    Article  CAS  Google Scholar 

  5. Konermann, L., Ahadi, E., Rodriguez, A.D., Vahidi, S.: Unraveling the mechanism of electrospray ionization. Anal. Chem. 85, 2–9 (2013)

    Article  CAS  Google Scholar 

  6. Tang, L., Kebarle, P.: Dependence of ion intensity in electrospray mass spectrometry on the concentration of the analytes in the electrosprayed solution. Anal. Chem. 65, 3654–3668 (1993)

    Article  CAS  Google Scholar 

  7. Constantopoulus, T.L., Jackson, G.S., Enke, C.G.: Effects of salt concentration on analyte response using electrospray ionization mass spectrometry. J. Am. Soc. Mass Spectrom. 10, 625–634 (1999)

    Article  Google Scholar 

  8. Kruve, A., Kaupmees, K., Liigand, J., Oss, M., Leito, I.: Sodium adduct formation efficiency in ESI source. J. Mass Spectrom. 48, 695–702 (2013)

    Article  CAS  Google Scholar 

  9. Yang, X.Y., Qu, Y., Yuan, Q., Wan, P., Du, Z., Chen, D., Wong, C.: Effect of ammonium on liquid- and gas-phase protonation and deprotonation in electrospray ionization mass spectrometry. Analyst 138, 659–665 (2012)

    Article  Google Scholar 

  10. van Berkel, G.J., McLuckey, S.A., Glish, G.L.: Electrochemical origin of radical cations observed in electrospray ionization mass spectra. Anal. Chem. 64, 1586–1593 (1992)

    Article  Google Scholar 

  11. Dole, M., Mack, L.L., Hines, R.L., Mobley, R.C., Ferguson, L.D., Alice, M.B.: Molecular beams of macroions. J. Chem. Phys. 49, 2240–2249 (1968)

    Article  CAS  Google Scholar 

  12. Iribarne, J., Thomson, B.: On the evaporation of small ions from charged droplets. J. Chem. Phys. 64, 2287–2294 (1976)

    Article  CAS  Google Scholar 

  13. Kebarle, P., Peschke, M.: On the mechanisms by which the charged droplets produced by electrospray lead to gas phase ions. Anal. Chim. Acta. 406, 11–35 (2000)

    Article  CAS  Google Scholar 

  14. Leito, I., Herodes, K., Huopolainen, M., Virro, K., Künnapas, A., Kruve, A., Tanner, R.: Towards the electrospray ionization mass spectrometry ionization efficiency scale of organic compounds. Rapid Commun. Mass Spectrom. 22, 379–384 (2008)

    Article  CAS  Google Scholar 

  15. Cech, N.B., Krone, J.P., Enke, C.G.: Predicting electrospray response from chromatographic retention time. Anal. Chem. 73, 208–213 (2001)

    Article  CAS  Google Scholar 

  16. Cech, N.B., Enke, C.G.: Relating electrospray ionization response to nonpolar character of small peptides. Anal. Chem. 72, 2717–2723 (2000)

    Article  CAS  Google Scholar 

  17. Oss, M., Kruve, A., Herodes, K., Leito, I.: Electrospray ionization efficiency scale of organic compounds. Anal. Chem. 82, 2865–2872 (2010)

    Article  CAS  Google Scholar 

  18. Huffman, B.A., Poltash, M.L., Hughey, C.A.: Effect of polar protic and polar aprotic solvents on negative-ion electrospray ionization and chromatographic separation of small acidic molecules. Anal. Chem. 84, 9942–950 (2012)

    Article  CAS  Google Scholar 

  19. Amad, M.H., Cech, N.B., Jackson, G.S., Enke, C.G.: Importance of gas-phase proton affinities in determining the electrospray ionization response for analytes and solvents. J. Mass Spectrom. 35, 784–789 (2000)

    Article  CAS  Google Scholar 

  20. Henriksen, T., Juhler, R.K., Svensmark, B., Cech, N.B.: The relative influences of acidity and polarity on responsiveness of small organic molecules to analysis with negative ion electrospray ionization mass spectrometry (ESI-MS). J. Am. Mass Spectrom. 16, 446–455 (2005)

    Article  CAS  Google Scholar 

  21. Nguyen, T.B., Nizkorodov, S.A., Laskin, A., Laskin, J.: An approach toward quantification of organic compounds in complex environmental samples using high-resolution electrospray ionization mass spectrometry. Anal. Methods 5, 72–80 (2013)

    Article  CAS  Google Scholar 

  22. Zhou, S., Hamburger, M.: Effects of solvent composition on molecular ion response in electrospray mass spectrometry: investigation of the ionization prozess. Rapid Commun. Mass Spectrom. 9, 1516–1521 (1995)

    Article  CAS  Google Scholar 

  23. Girod, M., Dagancy, X., Antoine, R., Dugourd, P.: Relation between charge state distributions of peptide anions and pH changes in the electrospray plume. A mass spectrometry and optical spectroscopy investigations. Int. J. Mass Spectrom. 308, 41–48 (2011)

    Article  CAS  Google Scholar 

  24. Girod, M., Dagancy, X., Boutou, V., Broyer, M., Antoine, R., Dugourd, P., Mordehai, A., Love, C., Werlich, M., Fjeldsted, J., Stafford, G.: Profiling an electrospray plume by laser-induced fluorescence and Fraunhofer diffraction combined to mass spectrometry: influence of size and composition of droplets on charge-state distributions of electrosprayed proteins. Phys. Chem. Chem. Phys. 14, 9389–9396 (2012)

    Article  CAS  Google Scholar 

  25. Ahadi, E., Konermann, L.: Ejection of solvated ions from electrosprayed methanol/water nanodroplets studied by molecular dynamics simulations. J. Am. Chem. Soc. 133, 9354–9363 (2011)

    Article  CAS  Google Scholar 

  26. Kaljurand, I., Kütt, A., Sooväli, L., Rodima, T., Mäemets, V., Leito, I., Koppel, I.: Extension of the self-consistent spectrophotometric basicity scale in acetonitrile to a full span of a 28 pK(a) units: Unification of different basicity scales. J. Org. Chem. 70, 1019–1028 (2005)

    Article  CAS  Google Scholar 

  27. Sooväli, L., Kaljurand, I., Kütt, A., Leito, I.: Uncertainity estimation in measurement of pK(a) values in nonaqueous media: a case study on basicity scale in acetonitrile medium. Anal. Chim. Acta. 566, 290–303 (2006)

    Article  Google Scholar 

  28. Greenspan, P., Fowler, S.: Spectrofluorometric studies of the lipid probe, nile red. J. Lipid Res. 26, 781–789 (1985)

    CAS  Google Scholar 

Download references

Acknowledgment

This work was supported by PUT 34 from Estonian Research Council as well as the institutional funding IUT20-14 (TLOKT14014I) from the Ministry of Education and Research of Estonia, and carried out in part at the High Performance Computing Center of the University of Tartu.

Author information

Authors and Affiliations

  1. Institute of Chemistry, Faculty of Science and Technology, University of Tartu, Ravila 14A, 50411, Tartu, Estonia

    Jaanus Liigand, Anneli Kruve & Ivo Leito

  2. Universite de Lyon, F-69622, Lyon, France

    Marion Girod & Rodolphe Antoine

  3. CNRS et Universite de Lyon 1, UMR 5280, ISA, 69100, Villeurbanne, France

    Marion Girod

  4. CNRS et Universite de Lyon 1, UMR 5306, ILM, 69622, Villeurbanne CEDEX, France

    Rodolphe Antoine

Authors
  1. Jaanus Liigand
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Anneli Kruve
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Ivo Leito
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Marion Girod
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Rodolphe Antoine
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Jaanus Liigand.

Electronic supplementary material

Below is the link to the electronic supplementary material.

ESM 1

(PDF 464 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Liigand, J., Kruve, A., Leito, I. et al. Effect of Mobile Phase on Electrospray Ionization Efficiency. J. Am. Soc. Mass Spectrom. 25, 1853–1861 (2014). https://doi.org/10.1007/s13361-014-0969-x

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s13361-014-0969-x

Key words

Search

Navigation