Paper
10 February 1999 Supersonic jet spectroscopy for environmental analysis
Author Affiliations +
Proceedings Volume 3534, Environmental Monitoring and Remediation Technologies; (1999) https://doi.org/10.1117/12.339040
Event: Photonics East (ISAM, VVDC, IEMB), 1998, Boston, MA, United States
Abstract
Dioxins and their precursors such as halogenated benzenes and phenols are suspected to be carcinogenic, and therefore they are required to be measured at ultratrace levels. Supersonic jet spectrometry combined with multiphoton ionization mass spectrometry is developed in this study for solving this problem. In order to improve the ionization yield, either 150-fs or 500-fs laser pulse is used as an excitation/ionization source, and the results are compared with those obtained using a 15-ns laser pulse. The ionization yield is substantially improved by decreasing the laser pulsewidth, which is explained by the short lifetime of the excited state for halogenated benzenes, which is arising from spin-orbit coupling and fast relaxation to the triplet state. In order to improve the sensitivity, i.e., to increase the number of ions induced by laser irradiation, a collinear ionization scheme is studied, in which the axis of jet expansion is designed to be identical to the direction of the ion drifting in the time-of-flight tube. The enhancement, by a factor of 50, in the ionization signal is achieved, which coincides with an expected value of 36 from a geometry. Supersonic jet spectrometry is also used for the detection of halogenated aromatic hydrocarbons formed by thermal decomposition of polyvinyl chloride and chlorinated polyvinyl chloride. Interestingly, chlorinated aromatic hydrocarbons are not detected from polyvinyl chloride but detected only from chlorinated polyvinyl chloride. Isomer specific determination of dichlorobenzene is also demonstrated in this study.
© (1999) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Totaro Imasaka "Supersonic jet spectroscopy for environmental analysis", Proc. SPIE 3534, Environmental Monitoring and Remediation Technologies, (10 February 1999); https://doi.org/10.1117/12.339040
Lens.org Logo
CITATIONS
Cited by 2 scholarly publications.
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Ionization

Spectroscopy

Ions

Molecules

Mass spectrometry

Pulsed laser operation

Chemical species

Back to Top