TY - JOUR
T1 - The effects of oxygen on the detection of mercury using laser-induced breakdown spectroscopy
AU - Gleason, R. L.
AU - Hahn, D. W.
N1 - Funding Information:
The authors gratefully acknowledge Brian Fisher for assistance with measurements, and Ben Smith (Department of Chemistry) for useful discussions. This work was supported in part by the US Department of Energy and US Department of Defense, Joint Services Demil Technology Office, in conjunction with Sandia National Laboratories.
PY - 2001/4/30
Y1 - 2001/4/30
N2 - A systematic study of the processes associated with mercury atomic emission in a laser-induced plasma and the interactions of mercury with oxygen species is presented. At early plasma decay times, on the order of 5-10 μs, no significant variation in mercury atomic emission was observed with the addition of oxygen-containing species. At intermediate and long decay times 10-100 μs, a significant reduction in the 253.7-nm mercury emission intensity was recorded with the introduction of oxygen-containing species. The decrease in mercury emission was temporally coincident with the recombination of atomic oxygen, as measured by the O(I) emission. The decreased mercury emission was not due to thermal effects, based on plasma temperature measurements, and was independent of the molecular source of oxygen, for similar concentrations of oxygen as air, carbon dioxide, and carbon monoxide. Analysis of additional mercury atomic emission lines revealed that the reduction in mercury emission in the presence of oxygen species is limited primarily to the 253.7-nm transition. In concert, the data lead to the conclusion that the 253.7-nm mercury emission line is selectively quenched by oxygen species, primarily O2 and NO, that are formed during the plasma recombination process. Implications for laser-induced breakdown spectroscopy-based emissions monitoring of mercury species are discussed.
AB - A systematic study of the processes associated with mercury atomic emission in a laser-induced plasma and the interactions of mercury with oxygen species is presented. At early plasma decay times, on the order of 5-10 μs, no significant variation in mercury atomic emission was observed with the addition of oxygen-containing species. At intermediate and long decay times 10-100 μs, a significant reduction in the 253.7-nm mercury emission intensity was recorded with the introduction of oxygen-containing species. The decrease in mercury emission was temporally coincident with the recombination of atomic oxygen, as measured by the O(I) emission. The decreased mercury emission was not due to thermal effects, based on plasma temperature measurements, and was independent of the molecular source of oxygen, for similar concentrations of oxygen as air, carbon dioxide, and carbon monoxide. Analysis of additional mercury atomic emission lines revealed that the reduction in mercury emission in the presence of oxygen species is limited primarily to the 253.7-nm transition. In concert, the data lead to the conclusion that the 253.7-nm mercury emission line is selectively quenched by oxygen species, primarily O2 and NO, that are formed during the plasma recombination process. Implications for laser-induced breakdown spectroscopy-based emissions monitoring of mercury species are discussed.
KW - Emissions monitoring
KW - Laser-induced breakdown spectroscopy
KW - Mercury
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U2 - 10.1016/S0584-8547(01)00169-0
DO - 10.1016/S0584-8547(01)00169-0
M3 - Article
AN - SCOPUS:0035971295
SN - 0584-8547
VL - 56
SP - 419
EP - 430
JO - Spectrochimica Acta - Part B Atomic Spectroscopy
JF - Spectrochimica Acta - Part B Atomic Spectroscopy
IS - 4
ER -