Simultaneous determination of As, Hg, Se and Sb by hydride generation-microwave induced plasma atomic emission spectrometry after preconcentration in a cryogenic trap

Abstract

In this paper a system is presented which combines hydride generation with a preconcentration step in a cryogenic trap and detection using MIP-AES. The MIP has been operating at atmospheric pressure with a forward power of 30-150 W, using a TM₀₁₀ cavity (Beenakker resonator), equipped with a tangential flow torch design. The plasma emission was observed end-on by the means of a CCD camera coupled to a 0.5 m Czerny-Turner design monochromator. Metal hydrides were generated batchwise in aqueous medium, preconcentrated in a liquid nitrogen cryogenic trap and then evaporated by electrical heating into the plasma discharge. The optimum working conditions have been found at the 197±7 nm window working with a forward power of 130 W, a plasma gas flow rate of 270 ml min^–1 of helium, a carrier gas flow rate of 134 ml min^–1 of helium, a NaBH₄ concentration of 2% and a HNO₃ concentration of 0.66 M. Under these conditions detection limits of 2.0, 13, 2.2 and 3.3 µg L^–1 for As, Hg, Se and Sb were achieved. The method was applied to the detemination of these analytes in spiked wastewater samples with recoveries of 95% or higher for all four analytes.

References

1. R. K. Skogerboe and G. N. Coleman, Anal. Chem., 1976, 48, 611A.
2. E. I. Brooks and K. J. Timmins, Analyst, 1985, 110, 557.
3. A. T. Zander and G. M. Hieftje, Appl. Spectrosc., 1981, 35, 357.
4. A. J. McCormack, S. C. Tong and W. D. Cooke, Anal. Chem., 1965, 37, 1470.
5. C. A. Bache and D. J. Lisk, J. Gas Chromatogr., 1968, 6, 301.
6. P. C. Uden, K. J. Slatkavitz, R. M. Barnes and R. L. Deming, Anal. Chim. Acta, 1986, 180, 401.
7. H. A. Moye, Anal. Chem., 1967, 39, 1441.
8. K. Tanabe, K. Chiba, H. Haraguchi and K. Fuwa, Anal. Chem., 1981, 53, 1450.
9. R. J. Watling, Anal. Chim. Acta, 1975, 75, 281.
10. M. M. Abdillahi and R. D. Snook, Analyst, 1986, 111, 265.
11. J. A. C. Broekaert and F. Lies, Mikrochim. Acta, 1985, II, 261.
12. J. H. Runnels and J. H. Gibson, Anal. Chem., 1967, 39, 1398.
13. P. Tschöpel, E. Bulska, J. A. C. Broekaert and G. Tölg, Anal. Chim. Acta, 1993, 271, 171.
14. U. Richts, J. A. C. Broekaert, P. Tschöpel and G. Tölg, Talanta, 1991, 38, 863.
15. T. Ishizuka and Y. Uwamino, Anal. Chem., 1980, 52, 125.
16. K. Jankowski, D. Karmasz, L. Starski, A. Ramsza and A. Waszkiewicz, Spectrochim. Acta, Part B, 1997, 52, 1801.
17. K. Jankowski, D. Karmasz, A. Ramsza and E. Reszke, Spectrochim. Acta, Part B, 1997, 52, 1813.
18. C. Veillon and M. Margoshes, Spectrochim. Acta, Part B, 1968, 23, 553.
19. K. G. Michlewicz and J. W. Carnahan, Anal. Chem., 1986, 58, 3122.
20. Q. Jin, C. Zhu, M. W. Borer and G. M. Hieftje, Spectrochim. Acta, Part B, 1991, 46, 417.
21. R. Pereiro, M. Wu, J. A. C. Broekaert and G. M. Hieftje, Spectrochim Acta, Part B, 1994, 49, 59.
22. H. Kawaguchi, T. Sakamoto and A. Mizuike, Talanta, 1973, 20, 321.
23. R. K. Skogerboe, D. L. Dick and F. E. Lichte, Anal. Chem., 1975, 47, 568.
24. O. F. X. Donard and R. Ritsema, in Environmental Analysis, ed. D. Barcelo, Elsevier, Amsterdam, The Netherlands, ch.16.
25. D. Falkin and M. Vosloo, Spectrosc. Europe, 1993, 5/5, 16.
26. C. Dietz, Y. Madrid, P. Quevauviller and C. Cámera, Quím. Analít., 1998, 17, 117.
27. T. Nakahara, Prog. Anal. At. Spectrosc., 1983, 6, 163.
28. X.-P. Yan and Z.-M. Ni, Anal. Chim. Acta, 1994, 291, 89.
29. A. D. Campbell, Pure Appl. Chem., 1992, 64, 227.
30. J. Agterdenbos and O. Bax, Fresenius Z. Anal. Chem., 1986, 323, 783.
31. B. Welz and M. Melcher, Analyst, 1984, 109, 573.
32. B. Jamoussi, M. Zafzouf and B. Ben Hassine, Fresenius Z. Anal. Chem., 1996, 356, 331.
33. A. Risnes and W. Lund, J. Anal. At. Spectrom., 1996, 11, 943.