Application of the 2f-wavelength modulation technique for the measurement of large lithium isotope ratios by diode laser graphite furnace atomic absorption spectroscopy

Authors
Citation
Hd. Wizemann, Application of the 2f-wavelength modulation technique for the measurement of large lithium isotope ratios by diode laser graphite furnace atomic absorption spectroscopy, SPECT ACT B, 54(9), 1999, pp. 1267-1278
Citations number
17
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences
Journal title
SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY
ISSN journal
05848547 → ACNP
Volume
54
Issue
9
Year of publication
1999
Pages
1267 - 1278
Database
ISI
SICI code
0584-8547(19990913)54:9<1267:AOT2MT>2.0.ZU;2-Q
Abstract
The measurement of large lithium isotope ratios by diode laser graphite fur nace atomic absorption spectroscopy was investigated using a low pressure a tomizer and 2f-wavelength modulation (WM) detection. The measurements were supported by computer simulations. Compared with a direct absorption measur ement, the relative absorption sensitivity for Li-6 is considerably reduced when 2f-WM is performed in the center of the Li-6 D1 fine structure compon ent, but it will be enhanced, when the center of modulation is tuned to the maximum in the red wing of the 2f-WM line profile. The results of calculat ed 2f-WM line strengths were used to deconvolute overlapping lines and enab led the measurement of Li-7/Li-6 isotope ratios as large as approximately 2 000. The Li content of a sample with a strong sodium chloride matrix was de termined by isotope dilution. (C) 1999 Elsevier Science B.V. All rights res erved.