Determination of Thallium in River Sediment by Flow Injection On-line Sorption Preconcentration in a Knotted Reactor Coupled With Electrothermal Atomic Absorption Spectrometry

Abstract

A flow injection on-line sorption preconcentration electrothermal atomic absorption spectrometric (ETAAS) method was developed for the determination of thallium. The Tl³⁺–tetramethylenedithiocarbamate (pyrrolidinedithiocarbamate) complex formed in strongly acidic medium (0–3 mol l^-1 HNO₃, 0–3 mol l^-1 H₂SO₄, 0–2.5 mol l ^-1 HClO₄ or 0–2 mol l^-1 HCl) is sorbed on the inner walls of a PTFE knotted reactor (100 cm × 0.5 mm id) and quantitatively eluted with 45 µl of ethanol. The ETAAS determination is performed in parallel with the preconcentration of the next sample. Using a preconcentration time of 30 s and a sample loading rate of 4.8 ml min^-1, an enhancement factor of 27 is obtained in comparison with direct injection of 45 µl of aqueous solution. The adsorption efficiency is 51%. The detection limit (3s) is 0.015 µg l^-1 and the precision (RSD) is 2.9% for 0.4 µg l^-1 Tl (n = 11). The accuracy of the method is demonstrated by the analysis of a Community Bureau of Reference certified reference material 320 river sediment (indicative value for thallium concentration).

References

1. D. L. Tsalev and Z. K. Zaprianov, Atomic Absorption Spectrometry in Occupational and Environmental Health Practice, Vol.1, Analytical Aspects and Health Significance, CRC Press, Boca Raton, FL, 1983, pp. 196–199.
2. A. M. Ure and M. L. Berrow, in Environmental Chemistry, ed. Bowen, H. J., Royal Society of Chemistry, London, 1982, vol. 2, pp. 155–195.
3. E. Weidmann, M. Stoeppler and P. Heininger, Analyst, 1992, 117, 295.
4. M. S. Leloux, N. P. Lich and J.-R. Claude, At. Spectrosc., 1987, 8, 72.
5. D. C. Manning and W. Slavin, Spectrochim. Acta, Part B, 1988, 43, 1157.
6. X.-Q. Shan, Z.-M. Ni and L. Zhang, Talanta, 1984, 31, 150.
7. C. W. Fuller, Anal. Chim. Acta, 1976, 81, 199.
8. W. Schmidt and F. Dietl, Fresenius' Z. Anal. Chem., 1983, 315, 687.
9. A. De Ruck, C. Vandecasteele and R. Dams, Anal. Lett., 1989, 22, 469.
10. G. P. Sighinolfi, At. Absorpt. Newsl., 1973, 12, 36.
11. M. Ikramuddin, At. Spectrosc., 1983, 4, 101.
12. E. Ivanova, M. Stoimenova and G. Gentscheva, Fresenius' J. Anal. Chem., 1994, 348, 317.
13. S. Tsakovski, E. Ivanova and I. Havezov, Talanta, 1994, 41, 721.
14. G. Calderoni and T. Ferri, Talanta, 1982, 29, 371.
15. J. P. Riley and S. A. Siddiqui, Anal. Chim. Acta, 1986, 181, 117.
16. H. Berndt, J. Messerschmidt, F. Alt and D. Sommer, Fresenius' Z. Anal. Chem., 1981, 306, 385.
17. H. Berndt, U. Harms and M. Sonneborn, Fresenius' Z. Anal. Chem., 1985, 322, 329.
18. Z. Fang, Flow Injection Atomic Absorption Spectrometry, Wiley, Chichester, 1995.
19. B. Mohammad, A. M. Ure and D. Littlejohn, Mikrochim. Acta, 1994, 113, 325.
20. H. Chen, S. Xu and Z. Fang, Anal. Chim. Acta, 1994, 298, 167.
21. Z. Fang, S. Xu, L. Dong and W. Li, Talanta, 1994, 41, 2165.
22. M. Sperling, X.-P. Yan and B. Welz, Spectrochim. Acta, Part B, 1996, 51, 1891.
23. X.-P. Yan, W. Van Mol and F. Adams, Analyst, 1996, 121, 1061.
24. X.-P. Yan, W. Van Mol and F. Adams, Lab. Robot. Autom., in the press.
25. X.-P. Yan, W. Van Mol and F. Adams, J. Anal. At. Spectrom., in the press.
26. X.-P. Yan, M. Sperling and B. Welz, to be published.
27. J. Stary, Solvent Extraction of Metal Chelates, Pergamon Press, Oxford, 1964.
28. W. H. Evans, P. J. Brooke and B. E. Lucas, Anal. Chim. Acta, 1983, 148, 203.
29. K. S. Subramanian and J. C. Meranger, Anal. Chim. Acta, 1981, 124, 131.
30. J. Ruzicka and A. Arndal, Anal. Chim. Acta, 1989, 216, 243.