Issue 18, 2016

The efficiencies of resonant and nonresonant multiphoton ionization in the femtosecond region

Abstract

Ionization efficiency in mass spectrometry was examined for three types of molecules under different ionization schemes, i.e., resonant/nonresonant and two-photon/three-photon ionization, using an ultraviolet (UV) femtosecond laser at different wavelengths, pulse energies, and pulse widths. The efficiency of nonresonant ionization could be improved substantially by decreasing the laser pulse width. The effect of resonance was minimal when an ultrashort optical pulse of less than 100 fs was employed for ionization in the UV region. Three-photon ionization was less efficient than two-photon ionization, but the difference was not significant at shorter pulse widths in the femtosecond region. Although the excess energy can be decreased by optimizing the laser wavelength in the case of nonresonant ionization, fragmentation was not suppressed in the cases studied here. However, fragmentation was drastically suppressed when the laser pulse width was decreased. Thus, this approach of using an ultrashort optical pulse would provide a new tool for soft ionization and then for more reliable identification of an analyte.

Graphical abstract: The efficiencies of resonant and nonresonant multiphoton ionization in the femtosecond region

Supplementary files

Article information

Article type
Paper
Submitted
10 Mar 2016
Accepted
02 Jun 2016
First published
06 Jun 2016

Analyst, 2016,141, 5274-5280

The efficiencies of resonant and nonresonant multiphoton ionization in the femtosecond region

H. Kouno and T. Imasaka, Analyst, 2016, 141, 5274 DOI: 10.1039/C6AN00577B

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements