Element-specific determination of chlorine in gases by Laser-Induced-Breakdown-Spectroscopy (LIBS).
An experimental set-up for the detection of elemental chlorine in chlorinated hydrocarbons (CHCs) is described based on a miniaturized system, which could be used for on-line monitoring of chlorinated compounds. With an optimized time-resolved detection chlorine from CHCs like CCl(4) can be determined by Laser-Induced-Breakdown-Spectroscopy (LIBS) with microg/g-detection limits in the gas phase. The application of a miniaturized Nd : YAG laser resulted only in a minor loss in performance, hence it could be used for designing a rugged and small on-line sensor. In addition, preliminary results for the detection of chlorine via the formation of CuCl in the plasma formed by focussing the laser on a copper surface are reported. Utilizing the luminescence of the CuCl D-system at 440 nm, a tenfold improvement in the detection limits was obtained. It appears that the formation of "ad hoc" selected, small molecules in a laser plasma could be a promising alternative for the selective and sensitive analysis of gaseous chlorinated and other species.
Haisch
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C
Institute of Hydrochemistry, Technical University of Munich, Marchioninistrasse 17, D-81377, München, Germany.
Niessner
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R
Matveev
O I
OI
Panne
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U
Omenetto
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N