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

Autor(es)

Tafurt-Cardona, Makenly ^{[1, 2]} ; Eismann, Carlos Eduardo ^[1] ; Suarez, Carlos Alfredo ^[1] ; Menegario, Amauri Antonio ^{[1, 2]} ; Luko, Karen Silva ^{[1, 2]} ; Sargentini Junior, Ezio ^[3]

Afiliação do(s) autor(es)

^[1] UNESP Univ Estadual Paulista, Ctr Estudos Ambientais, BR-13506900 Rio Claro, SP - Brazil

^[2] UNESP Univ Estadual Paulista, Inst Geociencias & Ciencias Exatas, Programa Posgrad Geociencias & Meio Ambiente, BR-13506900 Rio Claro, SP - Brazil

^[3] INPA, BR-69083000 Manaus, AM - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Analytica Chimica Acta; v. 887, p. 38-44, AUG 5 2015.
• Citações Web of Science: 8

Resumo

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 x 10(-6) cm(2) s(-1) at 23 degrees 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). (C) 2015 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 13/09020-4 - Avaliação de agentes ligantes alternativos na técnica de difusão em filmes finos por gradientes de concentração (DGT) para a determinação de metilmercúrio
• Beneficiário: Carlos Eduardo Eismann
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 15/03397-4 - Especiação e fracionamento de metais (e alguns semi-metais) em água e solo
• Beneficiário: Amauri Antonio Menegário
• Modalidade de apoio: Auxílio à Pesquisa - Regular