Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Resonant two-photon ionization spectroscopy in supersonic beams for discrimination of disubstituted benzenes in mass spectrometry

Journal Article · · Anal. Chem.; (United States)
DOI:https://doi.org/10.1021/ac00278a033· OSTI ID:5671440
Supersonic molecular beam spectroscopy has great potential for selectivity in chemical analysis. In this work we have used resonant two-photon ionization (R2PI) spectroscopy in supersonic beams of argon as a means of obtaining ultraviolet ionization spectra with sharp features for unique identification of species in a mixture. This technique, therefore, provides a wavelength-selective means of forming ions for detection in time-of-flight mass spectrometry. The spectroscopy of several disubstituted benzenes including p-cresol, p-toluidine, p-aminophenol, p-fluoroaniline, p-fluorophenol, and hydroquinone has been studied near their origin transitions. These molecules have low quantum yields in fluorescence but can be detected with great sensitivity (< 20 ppb) by using laser ionization. On the basis of the separation between spectral lines of compounds in various mixtures, we estimate the combined maximum discrimination possible in a mass spectrometer, thus demonstrating the capability of this technique for identification. When this method is used, an experimental discrimination between p-cresol and p-fluoroaniline on the order of 1:5000 can in principle be obtained.
Research Organization:
Univ. of Michigan, Ann Arbor
OSTI ID:
5671440
Journal Information:
Anal. Chem.; (United States), Journal Name: Anal. Chem.; (United States) Vol. 56:14; ISSN ANCHA
Country of Publication:
United States
Language:
English