Development of a binding agent for the technique of diffusive gradients in thin films (DGT) for in situ determination of metalloids

• Grant number: 11/12667-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2011
• End date: September 30, 2012
• Field of knowledge: Physical Sciences and Mathematics - Chemistry
• Principal Investigator: Paulo Sergio Tonello
• Grantee: Juan Saeta Farinha
• Host Institution: Universidade Estadual Paulista (UNESP). Campus Experimental de Sorocaba. Sorocaba , SP, Brazil

Abstract

Contamination of water bodies by the discharge of industrial and domestic effluents is a constant threat to human health and aquatic ecosystems. The monitoring of these environments is of a prime importance, and the diffusive gradients in thin-films technique (DGT) has been an important tool for such monitoring. The DGT commercially uses Chelex 100 as a binder resin, both for metals and metalloids. This project aims to develop and evaluate the performance of an alternative binding agent to the DGT technique: the AG1X8 resin immobilized on agarose gel. The performance of the new binder will be evaluated in situ for the determination of As, Se and Sb in aquatic environments. Agarose gel films impregnated with AG1X8 resin will be prepared. For the new binding agent, the retention time, the capacity retention of the analytes against different pH values and the best conditions for elution of the analytes will be evaluated. After that, the studies for the implementation of the new DGT binding agent in the technique will be directed to the analytes that are experiencing the best results. It will also be evaluated the behavior of the binding agent before the main variables that influence the DGT technique (ionic strength and immersion time) and the effects of potential interferences from concomitant ions. The DGT technique with the new binding agent will be then used in recovery tests performed with samples of natural waters plus the analytes. It is expected that the results of this project should lead to the development of new analytical methods, which allow the determination of metalloids in aquatic environments with in situ sampling. (AU)