Vapor generation in atomic spectrometry is a well established technique for the
determination of elements that can be volatilized by chemical reactions. In-situ
trapping in graphite furnaces is nowadays one of the most popular methods to
increase the sensitivity. In this study, resistively heated W-coil was used as an online
trap for preconcentration and revolatilization of volatile species of Bi, Cd and
Pb. The collected analyte species were revolatilized rapidly and sent to a quartz Ttube
atomizer for AAS measurement. Although the nature of revolatilized species
of Bi and Pb are not clear, they are probably molecular since they can be
transported at least 45 cm without any significant decrease in the peak height
values. However, cadmium is revolatilized from the trap surface as atoms.
The experimental parameters were optimized for the highest vapor generation,
trapping and revolatilization efficiencies. The concentration limits of detection
calculated by the 3 of blank solution were found to be 0.0027, 0.0040 and 0.015
ng/mL for Bi (18 mL), Cd (4.2 mL) and Pb (2 mL), respectively / enhancement
factors in the sensitivity were 130, 31 and 20, respectively. These values are
comparable with those obtained by in-situ trapping in graphite furnaces or even
ICP-MS found in the literature or better. Sensitivity can be improved further for Bi
and Cd using larger sample volumes, but purification of blank is required for Pb.
Certified standard reference materials were analyzed for the assessment of
accuracy of developed method.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12605049/index.pdf |
| Date | 01 May 2004 |
| Creators | Cankur, Oktay |
| Contributors | Ataman, Yavuz Osman |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | Ph.D. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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