title: Supercritical fluid extraction of organic and inorganic mercury from solid materials.
abstract: Mercuric ions (Hg(2+)) can be extracted from solid samples (cellulose matrix) using methanol modified supercritical CO(2) containing the fluorinated chelating agent lithium bis(trifluoroethyl)dithiocarbamate (LiFDDC). Methylmercuric chloride (CH(3)HgCl) and dimethylmercury [(CH(3))(2)Hg] can be extracted by supercritical CO(2) without chelating agent and modifier. The solubility of Hg(FDDC)(2) in supercritical CO(2) has been determined to be 5 x 10(-3)M at 5O degrees C and 150 atm, which is about 3 orders of magnitude greater than that of the non-fluorinated analogue Hg(DDC)(2). Use of methanol (5%)-modified CO(2) further enhances the solubility of Hg(FDDC)(2) by a factor of 2.4. A small amount of water added to the sample matrix tends to facilitate the extraction of Hg(FDDC)(2) and CH(3)HgCl. Potential applications of this in situ chelation-supercritical fluid extraction method for the preconcentration of mercury species and treatment of mercury contaminated wastes are discussed.
authors.affiliation: Department of Chemistry, University of Idaho, Moscow, ID 83843, U.S.A.
authors.forename: C M
authors.initials: CM
authors.lastname: Wai
authors.forename: Y
authors.initials: Y
authors.lastname: Lin
authors.forename: R
authors.initials: R
authors.lastname: Brauer
authors.forename: S
authors.initials: S
authors.lastname: Wang
authors.forename: W F
authors.initials: WF
authors.lastname: Beckert