N.A.F. Silva,a,* R.A.E. Leitão,a M.J. Matosa,b
aCentro de Investigação de Engenharia Química e Biotecnologia do ISEL/DEQ –
Av. Conselheiro Emídio Navarro, 1, 1949-014 Lisboa, Portugal
bInstituto Tecnológico – IST, Torre Norte, Piso 10, Av. Rovisco Pais, 1, 1049-001, Lisboa, Portugal
Abstract
In this work we tested the performance of the bismuth film electrode in the detection and simultaneous determination of toxic metals on real samples in a complex matrix, by square wave anodic stripping voltammetry. The studied samples were white poplar leaves gathered in “2ª Circular”, which is an area of major traffic intensity of the city of Lisbon.
The determined metals were Pb (II) and Cd (II). After being dried, the white poplar leaves were submitted to an acid digestion process assisted by microwave technology. A complete optimization study of the voltammetric parameters was made in order to simultaneously determine the metals as well as to decrease the detection limits and improve the method’s repeatability and sensitivity. The working electrode consisted in a bismuth film deposited on a vitreous carbon disc surface. The Ag/AgCl system was used as the reference electrode and a platinum wire as the auxiliary electrode. The concentrations (in mg of metal/kg of dry matter - leaves) obtained for Pb (II) and Cd (II) were of 3.0 and 1.7, respectively. Also, detection limits of 1.80 × 10-8 mol L-1 for Pb (II) and 6.90 × 10-9 mol L-1 for Cd (II) were estimated. In addition, a well shaped voltammogram obtained in the analysis of real samples opens excellent perspectives for the use of the bismuth electrode as an alternative to toxic metals such as mercurys.Keywords: bismuth electrode, toxic metals, stripping voltammetry, poplar leaves.
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References
1. S. Yohn, D. Long, J. Fett, L. Patino, Appl. Geochem. 19 (2004) 1157-1175. [ Links ]
2. G.J.K. Komarnicki, Environ. Pollut. 136 (2005) 47-61.
3. Z-W. Zhang, J-B. Qu, T. Watanabe, S. Shimbo, C-S. Moon, M. Ikeda, Toxicol. Lett. 108 (1999) 167-172.
4. A.B. Fischer, R. Georgieva, V. Nikolova, J. Halkova, A. Bainova, V. Hristeva, D. Penkov, D. Alandjiisk, Internat. J. Hygiene Environ. Health 206 (2003) 25-38.
5. M.C.V. Mamani, L.M. Aleixo, M.F. Abreu, S. Rath, J. Pharm. Biomed. Anal. 37 (2005) 709-713.
6. Kh.Z. Brainina, N.Yu. Stozhko, G.M. Belysheva, O.V. Inzhevatova, L.I. Kolyadina, C. Cremisini, M. Galletti, Anal. Chim. Acta 514 (2004) 227-234.
]]> 7. J. Brown, S. Sander, D. Craw, K. Hunter, Appl. Geochem. 20 (2005) 1533-1545.8. J. Wang, Stripping Analysis – Principles, Instrumentation and Applications, VCH Publishers, Deerfield Beach, FL, 1985.
9. J. Murimboh, M.T. Lam, N.M. Hassan, C.L. Chakrabarti, Anal. Chim. Acta 423 (2000) 115-126.
10. K. Siegel, U. Mauer, H. Keis, Eletrochim. Acta 42 (1997) 2955-2960.
11. O.A. Farghaly, M.A. Ghandour, Environ. Res. 97 (2005) 229-235.
12. R.A.A. Munoz, L. Angnes, Microchem. J. 77 (2004) 157-162.
13. S.C.C. Monterroso, H.M. Carapuça, J.E.J. Simão, A.C. Duarte, Anal. Chim. Acta 503 (2004) 203-212.
14. O.A. Farghaly, Microchem. J. 75 (2003) 119-131.
15. O.A. Farghaly, Talanta 63 (2004) 497-501.
16. H.M. Carapuça, S.C.C. Monterroso, L.S. Rocha, A.C. Duarte, Talanta 64 (2004) 566-569.
]]> 17. Y. Bonfil, M. Brand, E. Kirowa-Eisner, Anal. Chim. Acta 424 (2000) 65-76.18. Y. Bonfil, M. Brand, E. Kirowa-Eisner, Anal. Chim. Acta 387 (1999) 85-89.
19. J.M. Friedrich, C. Ponce-de-Léon, G.W. Reade, F.C. Walsh, J. Electroanal. Chem. 561 (2004) 203-217.
20. B. Uslu, B. Dogan, S.A. Ozkan, H.Y. Aboul-Enein, Anal. Chim. Acta 552 (2005) 127-134.
21. I. Svancara, P. Kotzian, M. Bartos, K. Vytras, Electrochem. Commun. 7 (2005) 657-662.
22. I. Svancara, K. Vytras, J. Barek, J. Zima, Critical Rev. Anal. Chem. 31 (2001) 311-345.
23. Z. Hu, C.J. Seliskar, W.R. Heineman, Anal. Chim. Acta 369 (1998) 93-101.
24. K. Brainina, H. Schafer, A. Ivanova, R. Khanina, Anal. Chim. Acta 330 (1996) 175-181.
25. A. Economou, TrAC, Trends Anal. Chem. 24 (2005) 334-340.
26. J. Wang, J. Lu, U.A. Kirgoz, S.B. Hocevar, B. Ogorevc, Anal. Chim. Acta 434 (2001) 29-34.
]]> 27. M. Yang, Z. Hu, J. Electroanal. Chem. 583 (2005) 46-55.28. Z. Guo, F. Feng, Y. Hou, N.J. Renault, Talanta 65 (2005) 1052-1055.
29. D. Demetriades, A. Economou, A. Voulgaropoulos, Anal. Chim. Acta 519 (2004) 167-172.
30. G. Kefala, A. Economopu, A. Vougaropoulos, M. Sofoniou, Talanta 61 (2003) 603-610.
31. W. Frenzel, Anal. Chim. Acta 273 (1993) 123-137.
32. V. Sandroni, C.M.M. Smith, A. Donovan, Talanta 60 (2003) 715-723.
33. J. Sastre, A. Shauquillo, M. Vidal, G. Rauret, Anal. Chim. Acta 462 (2002) 59-72.
34. Y. Saavedra, A. González, P. Fernández, J. Blanco, Spectrochim. Acta, Part B 59 (2004) 533-541.
35. E. Fischer, C.M.G. Van den Berg, Anal. Chim. Acta 385 (1999) 273-280.
36. M.P.M.M. Neto, M.M.G.S. Rocha, I.M.N. Campos, Portugaliae Electrochim. Acta 19 (2001) 57-71.
]]> 37. D.L. Massart, B.G.M. Vandeginste, S.N. Deming, Y. Michotte, L. Kaufman, Chemometrics: A Textbook, Ed. B.G.M. Vandeginste, L. Kaufman, Elsevier, Amesterdam, 1998.38. C. Locatelli, G. Torsi, Microchem. J. 78 (2004) 175-180.
39. N.A.F. Silva, M.I. Lopes, R.A.E. Leitão, H. Silva, M.J. Matos, J. Braz. Chem. Soc. Article in Press.
40. N.A.F. Silva, MSc. Dissertation, Faculdade de Ciências da Universidade de Lisboa, Portugal 2003.
*Corresponding author. E-mail address: nsilva@deq.isel.ipl.pt
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