In situ chemical fractionation and speciation analysis using the diffusive gradients in thin films technique (DGT)

Abstract

The main goal of this project is to implement researches able to give basic and reliable information for environment studies. Sensitive and selective methods (based on diffusive gradients in thin films technique) for in situ fractionation and speciation analysis in aquatic system will be developed. The studies for fractionation will cover the determination of labile, inorganic and/or organic fractions of Al, Cd, Co, Cu, Mn, Ni, Pb, Zn and it will be performed, generally, by using conventional DGT materials. For speciation analysis, experiments based on use of DGT, DET (Diffusive Equilibrium in Thin Films) will be performed. Also approaches based on use of selective binding agents will be used. Species of As, Hg, Cr, P, Pb, S, Sb, Se, Sn and U are the mains analytes. After the iterations between the binding agent and the analytes (and the possibility for speciation analysis) have been known, the studies will focus the evaluation the effect of pH, ionic strength and deployment time. Also tests to evaluate the effect of the interfering species and the accuracy of the proposed approaches for analysis of river water will be evaluated. Finally, the proposed DGT devices will be applied for in situ analysis (sea and river water). The prospect to analyze sediment and soils sample will be evaluated.Despite research based on DGT technique will be the major focus in this project, other techniques for speciation analysis and fractionation will be used. For example: hyphenated techniques (for speciation analysis), solid phase extraction and use of biomonitors (for fractionation). The main areas of studies for application of the proposed approaches are aquatic system from Amazon basin (Amazonas, Brazil), Corumbataí basin (São Paulo, Brazil) and near to mining areas (mainly U, Minas Gerais, Brazil). Deployments in marine environment will be performed southeast of Brazil (São Paulo and Rio de Janeiro). (AU)