Laser-enhanced ionization of mercury atoms in an inert atmosphere with avalanche amplification of the signal
- Clevenger, W.L. 3
- Matveev, O.I. 1
- Cabredo, S. 2
- Omenetto, N. 4
- Smith, B.W. 3
- Winefordner, J.D. 3
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1
Moscow State University
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2
Universidad de La Rioja
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3
University of Florida
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- 4 Environment Institute, Joint Research Centre, Ispra, (Va), Italy
ISSN: 0003-2700
Année de publication: 1997
Volumen: 69
Número: 13
Pages: 2232-2237
Type: Article
beta Ver similares en nube de resultadosD'autres publications dans: Industrial and Engineering Chemistry. Analytical Chemistry.
Résumé
A new method for laser-enhanced ionization detection of mercury atoms in an inert gas atmosphere is described. The method, which is based on the avalanche amplification of the signal resulting from the ionization from a selected Rydberg level reached by a three-step laser excitation of mercury vapor in a simple quartz cell, can be applied to the determination of this element in various matrices by the use of conventional cold atomization techniques. The overall (collisional + photo) ionization efficiency is investigated at different temperatures, and the avalanche amplification effect is reported for Ar and P-10 gases at atmospheric pressure. It is shown that the amplified signal is related to the number of charges produced in the laser-irradiated volume. Under amplifier noise-limited conditions, a detection limit of ∼15 Hg atoms/laser pulse in the interaction region is estimated.