Progress in direct solid sampling analysis using line source and high-resolution continuum source electrothermal atomic absorption spectrometry |
| |
Authors: | Bernhard Welz Maria Goreti R Vale Daniel L G Borges Uwe Heitmann |
| |
Institution: | Departamento de Química, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, SC, Brazil. w.bernardo@terra.com.br |
| |
Abstract: | The literature about direct solid sample analysis of the past 10–15 years using electrothermal atomic absorption spectrometry
has been reviewed. It was found that in the vast majority of publications aqueous standards were reported as having been used
for calibration after careful program optimization. This means the frequently expressed claim that certified reference materials
with a matrix composition and analyte content close to that of the sample have to be used for calibration in solid sample
analysis is not confirmed in the more recent literature. There are obviously limitations, and there are examples in the literature
where even calibration with certified reference materials did not lead to accurate results. In these cases the problem is
typically associated with spectral interferences that cannot be corrected properly by the systems available for conventional
line source atomic absorption spectrometry, including Zeeman-effect background correction. Using high-resolution continuum
source atomic absorption spectrometry, spectral interferences become visible owing to the display of the spectral environment
at both sides of the analytical line at high resolution, which makes program optimization straightforward. Any spectrally
continuous background absorption is eliminated automatically, and even rapidly changing background absorption does not cause
any artifacts, as measurement and correction of background absorption are truly simultaneous. Any kind of fine-structured
background can be eliminated by “subtracting” reference spectra using a least-squares algorithm. Aqueous standards are used
for calibration in all published applications of high-resolution continuum source atomic absorption spectrometry to direct
solid sample analysis.
This contribution is based on a presentation given at the Colloquium for Analytical Atomic Spectroscopy (CANAS ‘07) held March
18–21, 2007 in Constance, Germany. |
| |
Keywords: | Direct solid sample analysis Electrothermal atomic absorption spectrometry High-resolution continuum source atomic absorption spectrometry Background correction Calibration |
本文献已被 PubMed SpringerLink 等数据库收录! |
|