Binding agents immobilized on agarose using the diffusive gradients in thin films

• Grant number: 19/15246-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): August 01, 2019
• Effective date (End): September 30, 2021
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Amauri Antonio Menegário
• Grantee: Edson Geraldo de Oliveira Junior
• Host Institution: Centro de Estudos Ambientais (CEA). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil
• Associated research grant: 16/14227-5 - Climatic changes and environmental impacts in wetlands of Pantanal region (Brazil): quantification, control factors and long term temporal modeling, AP.PFPMCG.TEM

Abstract

In the diffusion gradients in thin films technique (DGT) for determination of trace elements in situ, a device continuously absorbs over time the analytic in the environment, basically using a diffusive gel and a binding gel. In the binding gel, the analytic will be retained for further analysis, with appropriate methods, to determine the accumulated mass of the element of interest in the disc. Then the concentration of the analytic in the environment will be determined through the immersion time, exposure window, diffusion coefficient and diffusive gel thickness. The technique was developed by Zhang and Davidson, currently marketed by the company DGT® Research, owner of the cross-linker patent, acrylamide-based substance, used in the binding and diffusive medium for cohesion of the gel. The DGTs devices have relatively high aggregated values, particularly due to the costs of gels and import taxes, especially considering the use of a large number of devices in every area to be studied. With agarose, which has low cost, it is possible to produce diffusive gel in the laboratory and immobilize resin (or other binding materials), replacing the use of polyacrylamide and consequently the importation of gels. The sorbent varies according to the element to be retained, with Chelex-100 being efficient for cations and anion-efficient zirconium oxide. This work aims to use agarose as diffusive gel and for immobilization of at least Chelex-100 and zirconium oxide separately and/or simultaneously. The diffusion coefficient of the agarose, the efficiency of the retention of the analyses in the laboratory (under different conditions of pH and ionic strength) will be evaluated. Also, it will be evaluated and/or developed processes of elution of the analyses that have been retained in the new disks. The determination of analytic concentrations will be performed by Indutively Coupled Argon Plasma - Mass Spectrometry (ICP-MS).