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

Author(s)

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]

Affiliation

^[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

• Document type: Journal article
• Source: Analytica Chimica Acta; v. 887, p. 38-44, AUG 5 2015.
• Web of Science Citations: 8

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 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)

• FAPESP's process: 13/09020-4 - Evaluation of alternative binding agents in the diffusive gradients in thin films technique (DGT) for determination of methylmercury
• Grantee: Carlos Eduardo Eismann
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 15/03397-4 - Speciation and fractionation of metals (and some metalloids) in water and soil
• Grantee: Amauri Antonio Menegário
• Support Opportunities: Regular Research Grants