Resumen

FLORES, Éder L. M. et al. Mercury speciation in urban landfill leachate by cold vapor generation atomic absorption spectrometry using ion exchange and amalgamation. J. Braz. Chem. Soc. [online]. 2009, vol.20, n.9, pp. 1659-1666. ISSN 0103-5053.  http://dx.doi.org/10.1590/S0103-50532009000900014.

This work deals with on line speciation of organic Hg (Hg_org) and inorganic Hg (Hg_inorg) in urban landfill leachate. Chlorocomplexes of Hg_inorg are produced in HCl medium and retained on an anion exchange column. The retained Hg is eluted with NaBH₄ in presence of HCl. Hg⁰ is produced and then measured by cold vapor atomic absorption spectrometry (CV AAS). Hg_org does not interact with the resin and is mixed with NaBH₄ at the exit of the column producing volatile species of Hg that are then amalgamated by a gauze of Au/Pt. Mercury is removed from the gauze by heating to 600 °C and subsequently measured by CV AAS. For Hg_inorg and Hg_org speciation in urban landfill leachate, the samples are centrifuged, filtered and treated with HCl. The detection limits (3 s) of Hg_inorg and Hg_org are 9 and 12 ng L^-1 of Hg, respectively. The analysis frequency is 22 h^-1.

Palabras llave : mercury speciation; landfill leachate; flow analysis; ion exchange; amalgamation; CVG AAS.