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Comparative tests on the efficiency of three methods of methylmercury extraction in environmental samples
1999; Wiley; Volume: 13; Issue: 7 Linguagem: Inglês
10.1002/(sici)1099-0739(199907)13
ISSN1099-0739
AutoresElcia Margareth Souza Brito, Jean Rémy Davée Guimarães,
Tópico(s)Heavy Metal Exposure and Toxicity
ResumoApplied Organometallic ChemistryVolume 13, Issue 7 p. 487-493 Research Article Comparative tests on the efficiency of three methods of methylmercury extraction in environmental samples E. M. S. Brito, E. M. S. Brito Instituto de Biofisica Carlos Chagas Filho, Lab. de Radioisótopos Eduardo Penna Franca, Bloco G-CCS, UFRJ-Ilha do Fundão, Rio de Janeiro, RJ, 21949-900 BrazilSearch for more papers by this authorJ. R. D. Guimarães, Corresponding Author J. R. D. Guimarães Instituto de Biofisica Carlos Chagas Filho, Lab. de Radioisótopos Eduardo Penna Franca, Bloco G-CCS, UFRJ-Ilha do Fundão, Rio de Janeiro, RJ, 21949-900 BrazilInstituto de Biofisica Carlos Chagas Filho, Lab. de Radiosótopos Eduardo Penna Franca, Bloco G-CCS, UFRJ-Ilha do Fundão, Rio de Janeiro, RJ, 21949-900 Brazil.Search for more papers by this author E. M. S. Brito, E. M. S. Brito Instituto de Biofisica Carlos Chagas Filho, Lab. de Radioisótopos Eduardo Penna Franca, Bloco G-CCS, UFRJ-Ilha do Fundão, Rio de Janeiro, RJ, 21949-900 BrazilSearch for more papers by this authorJ. R. D. Guimarães, Corresponding Author J. R. D. Guimarães Instituto de Biofisica Carlos Chagas Filho, Lab. de Radioisótopos Eduardo Penna Franca, Bloco G-CCS, UFRJ-Ilha do Fundão, Rio de Janeiro, RJ, 21949-900 BrazilInstituto de Biofisica Carlos Chagas Filho, Lab. de Radiosótopos Eduardo Penna Franca, Bloco G-CCS, UFRJ-Ilha do Fundão, Rio de Janeiro, RJ, 21949-900 Brazil.Search for more papers by this author First published: 02 July 1999 https://doi.org/10.1002/(SICI)1099-0739(199907)13:7 3.0.CO;2-BCitations: 9AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Abstract Mercury is used in gold mining in the Brazilian Amazon and released in significant amounts to the environment as Hg0. After its oxidation it may be methylated, mainly in bottom sediments and in the rhizosphere of floating aquatic macrophytes. Methylmercury (MeHg) is highly bioavailable and subject to biomagnification. The objective of this work was to evaluate the efficiency of three methylmercury extraction techniques, applied to replicates of environmental samples (stream sediments from Floresta da Tijuca, Rio de Janeiro; and roots of the floating macrophyte Eichhornia crassipes from Lagoinha, Rio de Janeiro) previously incubated with 203Hg2+. Method A is based on acid leaching and extraction of Me203Hg in toluene. Method B uses alkaline digestion, extraction in dithizone–benzene and separation of organic and inorganic 203Hg dithizonates by thin-layer chromatography (TLC). Method C consists in separating the Me203Hg from the sample matrix by distillation. Total 203Hg and Me203Hg were detected by gamma spectrometry or liquid scintillation. For both matrices, Me203Hg extraction efficiency was better for smaller samples (range: 0.08–0.5 g for sediment, 0.1–0.5 g for E. crassipes roots). For the sediment samples, the three selected methods presented similar Me203Hg extraction efficiencies: 7–13, 5–14 and 4–17% of total added 203Hg was found as MeHg for procedures A, B and C, respectively. For E. crassipes roots, on the other hand, a lower extraction efficiency was obtained for the procedure C (11–28% of total 203Hg present as Me203Hg) than for methods B (22–36%) and A (20–44%). In all the root samples prepared with procedure B, a strong and durable chemiluminescence effect was observed, which required measuring the final Me203Hg extracts by gamma spectrometry only. In the specific conditions we used, extraction via distillation required re-extraction of Me203Hg in the distillate, due to the presence of traces of inorganic 203Hg in the latter. Copyright © 1999 John Wiley & Sons, Ltd. Citing Literature Volume13, Issue7July 1999Pages 487-493 RelatedInformation
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