title: In situ selective determination of methylmercury in river water by diffusive gradient in thin films technique (DGT) using baker's yeast (Saccharomyces cerevisiae) immobilized in agarose gel as binding phase.
abstract: Saccharomyces cerevisiae immobilized in agarose gel as binding phase and polyacrylamide as diffusive layer in the diffusive gradient in thin films technique (DGT) was used for selective determination of methylmercury (MeHg). Deployment tests showed good linearity in mass uptake up to 48 h (3276 ng). When coupling the DGT technique with Cold Vapor Atomic Fluorescence Spectrometry, the method has a limit of detection of 0.44 ng L(-1) (pre concentration factor of 11 for 48 h deployment). Diffusion coefficient of 7.03 ± 0.77 × 10(-6) cm(2) s(-1) at 23 °C in polyacrylamide gel (pH = 5.5 and ionic strength = 0.05 mol L(-1) NaCl) was obtained. Influence of ionic strength (from 0.0005 mol L(-1) to 0.1 mol L(-1) NaCl) and pH (from 3.5 to 8.5) on MeHg uptake were evaluated. For these range, recoveries of 84-105% and 84-98% were obtained for ionic strength and pH respectively. Potential interference due to presence of Cu, Fe, Mn, Zn was also assessed showing good recoveries (70-87%). The selectivity of the proposed approach was tested by deployments in solutions containing MeHg and Hg(II). Results obtained showed recoveries of 102-115 % for MeHg, while the uptake of Hg(II) was insignificant. The proposed approach was successfully employed for in situ measurements in the Negro River (Manaus-AM, Brazil).
authors: Programa de Pós-graduação em Geociências e Meio Ambiente, Instituto de Geociências e Ciências Exatas, UNESP - Univ. Estadual Paulista, Av. 24-A, 1515, CEP: 13506-900, Rio Claro, SP, Brazil; Centro de Estudos Ambientais, UNESP - Univ. Estadual Paulista, Av. 24-A, 1515, CEP: 13506-900, Rio Claro, SP, Brazil.
authors: Makenly
authors: M
authors: Tafurt-Cardona
authors: Centro de Estudos Ambientais, UNESP - Univ. Estadual Paulista, Av. 24-A, 1515, CEP: 13506-900, Rio Claro, SP, Brazil.
authors: Carlos Eduardo
authors: CE
authors: Eismann
authors: Centro de Estudos Ambientais, UNESP - Univ. Estadual Paulista, Av. 24-A, 1515, CEP: 13506-900, Rio Claro, SP, Brazil.
authors: Carlos Alfredo
authors: CA
authors: Suárez
authors: Programa de Pós-graduação em Geociências e Meio Ambiente, Instituto de Geociências e Ciências Exatas, UNESP - Univ. Estadual Paulista, Av. 24-A, 1515, CEP: 13506-900, Rio Claro, SP, Brazil; Centro de Estudos Ambientais, UNESP - Univ. Estadual Paulista, Av. 24-A, 1515, CEP: 13506-900, Rio Claro, SP, Brazil. Electronic address: amenega@rc.unesp.br.
authors: Amauri Antonio
authors: AA
authors: Menegário
authors: Programa de Pós-graduação em Geociências e Meio Ambiente, Instituto de Geociências e Ciências Exatas, UNESP - Univ. Estadual Paulista, Av. 24-A, 1515, CEP: 13506-900, Rio Claro, SP, Brazil; Centro de Estudos Ambientais, UNESP - Univ. Estadual Paulista, Av. 24-A, 1515, CEP: 13506-900, Rio Claro, SP, Brazil.
authors: Karen
authors: K
authors: Silva Luko
authors: Instituto Nacional de Pesquisas da Amazônia (INPA), CP 478, 69083-000 Manaus, AM, Brazil.
authors: Ézio
authors: É
authors: Sargentini Junior
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D001938:Brazil; D018914:Cells, Immobilized / Q000378:metabolism; D004058:Diffusion; D004784:Environmental Monitoring / Q000379:methods*; D005782:Gels / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008767:Methylmercury Compounds / Q000032:analysis* / Q000302:isolation & purification / Q000378:metabolism; D009994:Osmolar Concentration; D045483:Rivers / Q000737:chemistry*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D012685:Sepharose / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D005782:Gels; D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical; D012685:Sepharose
keywords: Mercury; Methylmercury; Passive sampler; Saccharomyces cerevisiae