Paper-based diffusive gradients in thin films technique coupled to energy dispersive X-ray fluorescence spectrometry for the determination of labile Mn, Co, Ni, Cu, Zn and Pb in river water


Autoria(s): de Almeida, Eduardo; do Nascimento Filho, Virgilio Franco; Menegario, Amauri Antonio
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO

Data(s)

25/10/2013

25/10/2013

2012

Resumo

The diffusive gradients in thin films (DGT) technique has shown enormous potential for labile metal monitoring in fresh water due to the preconcentration, time-integrated, matrix interference removal and speciation analytical features. In this work, the coupling of energy dispersive X-ray fluorescence (EDXRF) with paper-based DGT devices was evaluated for the direct determination of Mn, Co. Ni, Cu, Zn and Pb in fresh water. The DGT samplers were assembled with cellulose (Whatman 3 MM chromatography paper) as the diffusion layer and a cellulose phosphate ion exchange membrane (Whatman P 81 paper) as the binding agent. The diffusion coefficients of the analytes on 3 MM chromatography paper were calculated by deploying the DGT samplers in synthetic solutions containing 500 mu g L-1 of Mn. Co, Ni, Cu, Zn and Pb (4 L at pH 5.5 and ionic strength at 0.05 mol L-1). After retrieval, the DGT units were disassembled and the P81 papers were dried and analysed by EDXRF directly. The 3 MM chromatographic paper diffusion coefficients of the analytes ranged from 1.67 to 1.87 x 10(-6) cm(2) s(-1). The metal retention and phosphate group homogeneities on the P81 membrane was studied by a spot analysis with a diameter of 1 mm. The proposed approach (DGT-EDXRF coupling) was applied to determine the analytes at five sampling sites (48 h in situ deployment) on the Piracicaba river basin, and the results (labile fraction) were compared with 0.45 mu m dissolved fractions determined by synchrotron radiation-excited total reflection X-ray fluorescence (SR-TXRF). The limits of detection of DGT-EDXRF coupling for the analytes (from 7.5 to 26 mu g L-1) were similar to those obtained by the sensitive SR-TXRF technique (3.8 to 9.1 mu g L-1). (C) 2012 Elsevier B.V. All rights reserved.

FAPESP

FAPESP

CNPq

CNPq

LNLS Brazilian Synchrotron Light Laboratory/MCT

LNLS - Brazilian Synchrotron Light Laboratory/MCT [D09-XRF-10113]

Identificador

SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY, OXFORD, v. 71-72, n. 3, supl. 1, Part 1, pp. 70-74, MAY-JUN, 2012

0584-8547

http://www.producao.usp.br/handle/BDPI/36083

10.1016/j.sab.2012.05.006

http://dx.doi.org/10.1016/j.sab.2012.05.006

Idioma(s)

eng

Publicador

PERGAMON-ELSEVIER SCIENCE LTD

OXFORD

Relação

SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY

Direitos

closedAccess

Copyright PERGAMON-ELSEVIER SCIENCE LTD

Palavras-Chave #FRESH WATER #PAPER-BASED DGT #EDXRF #SR-TXRF #TRACE-METAL SPECIATION #BINDING PHASE #DGT #FLOW #SPECTROSCOPY
Tipo

article

original article

publishedVersion