Matrix effects in the detection of Pb and Ba in soils using laser-induced breakdown spectroscopy
- Chemical Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
- Earth and Environmental Science Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
With the use of laser-induced breakdown spectroscopy (LIBS), the effects of chemical speciation and matrix composition on Pb and Ba measurements have been investigated by using sand and soil matrices. A cylindrical lens was used to focus the laser pulses on the samples because it yielded higher measurement precision than a spherical lens for the experimental conditions used here. The detection limits for Pb and Ba spiked in a sand matrix were 17 and 76 ppm (w/w), respectively. In spiked soil, the detection limits were 57 and 42 ppm (w/w) for Pb and Ba, respectively. Measurement precision for five replicate measurements was typically 10{percent} RSD or less. Two factors were found to influence emissions from Pb and Ba present in sand and soil matrices as crystalline compounds: (1) compound speciation, where Ba emission intensities varied in the order carbonate{gt}oxide{gt}sulfate{gt}chloride{gt}nitrate, and where Pb emission intensities varied in the order oxide{gt}carbonate{gt}chloride{gt}sulfate{gt}nitrate; and (2) the composition of the bulk sample matrix. Emissions from Ba(II) correlated inversely with the plasma electron density, which in turn was dependent upon the percent sand in a sand/soil mixture. The analytical results obtained here show that a field-screening instrument based on LIBS would be useful for the initial screening of soils contaminated with Pb and Ba. {copyright} {ital 1996 Society for Applied Spectroscopy.}
- OSTI ID:
- 467175
- Journal Information:
- Applied Spectroscopy, Journal Name: Applied Spectroscopy Journal Issue: 9 Vol. 50; ISSN 0003-7028; ISSN APSPA4
- Country of Publication:
- United States
- Language:
- English
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