Comparison of Internal Energy Distributions of Ions Created by Electrospray Ionization and Laser Ablation-Liquid Vortex Capture-Electrospray Ionization

Journal Article · Sat Jun 27 00:00:00 EDT 2015 · Journal of the American Society for Mass Spectrometry

DOI:https://doi.org/10.1007/s13361-015-1195-x· OSTI ID:1235006

Cahill, John F. ^[1]; Kertesz, Vilmos ^[1]; Ovchinnikova, Olga S. ^[1]; Van Berkel, Gary J. ^[1]

---

1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Recently a number of techniques have combined laser ablation with liquid capture for mass spectrometry spot sampling and imaging applications. The newly developed non-contact liquid-vortex capture probe has been used to efficiently collect 355 nm UV laser ablated material in a continuous flow solvent stream in which the captured material dissolves and then undergoes electrospray ionization. This sampling and ionization approach has produced what appear to be classic electrospray ionization spectra; however, the softness of this sampling/ionization process versus simple electrospray ionization has not been definitely determined. A series of benzlypyridinium salts, known as thermometer ions, were used to compare internal energy distributions between electrospray ionization and the UV laser ablation liquid-vortex capture probe electrospray combination. Measured internal energy distributions were identical between the two techniques, even with differences in laser fluence (0.7-3.1 J cm-2) and when using UV-absorbing or non-UV-absorbing sample substrates. This data indicates ions formed directly by UV laser ablation, if any, are likely an extremely small constituent of the total ion signal observed. Instead, neutral molecules, clusters or particulates ejected from the surface during laser ablation, subsequently captured and dissolved in the flowing solvent stream then electrosprayed are the predominant source of ion signal observed. The electrospray ionization process used controls the softness of the technique.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1235006
• Journal Information: Journal of the American Society for Mass Spectrometry, Vol. 26, Issue 9; ISSN 1044-0305
• Publisher: American Society for Mass Spectrometry
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
Laser ablation Liquid capture Electrospray ionization Thermometer ions Internal energy Surface sampling Mass spectrometry imaging