title: Determination of labile barium in petroleum-produced formation water using paper-based DGT samplers.
abstract: A polyacrylamide hydrogel containing the Chelex-100 resin has traditionally been used as the binding agent for the diffusion gradients in thin films (DGT) technique. The Chelex-100 resin, although important for the determination of various transition metals, is unsatisfactory for the determination of alkaline earth metals, particularly Ba. In this paper, a cellulose membrane, treated with phosphate (P81 membrane), was evaluated as a binding agent for DGT devices for the determination of Ba in produced formation water (PFW) samples. In addition, diffusive layers of filter paper (cellulose) were tested to diffuse Ba through the DGT devices. Experiments to evaluate the key variables of the technique (pH, deployment time, and ionic strength/salinity) were performed. The Ba sampled by these DGT devices was measured using inductively coupled plasma optical emission spectrometry. Aiming to generate information (related to bioavailability of Ba) on the reuse of PFW for irrigation, the determination of Ba in onshore and offshore samples was performed. The new approach was effective for determination of Ba in onshore samples. To determine Ba in offshore samples, it was necessary to use an alternative calibration procedure due to the high NaCl concentration in these samples.
authors.affiliation: 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.
authors.forename: Wellington
authors.initials: W
authors.lastname: de Oliveira
authors.forename: Maria de Fátima Batista
authors.initials: Mde F
authors.lastname: de Carvalho
authors.forename: Eduardo
authors.initials: E
authors.lastname: de Almeida
authors.forename: Amauri Antonio
authors.initials: AA
authors.lastname: Menegário
authors.forename: Roberto
authors.initials: R
authors.lastname: Naves Domingos
authors.forename: Ana Luiza
authors.initials: AL
authors.lastname: Brossi-Garcia
authors.forename: Virgílio Franco
authors.initials: VF
authors.lastname: do Nascimento Filho
authors.forename: Ricardo Erthal
authors.initials: RE
authors.lastname: Santelli