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