A simple, green and low-cost agarose-based binding layer for simultaneous determination of cations and anions in aquatic systems using DGT

Author(s)

Eismann, Carlos Eduardo ; Menegario, Amauri Antonio ; de Oliveira Jr, Edson Geraldo ; Elias, Lucas Pellegrini ; Viana, Jose Lucas Martins ; Zanatta, Melina Borges Teixeira ; Barbiero, Laurent ; Fostier, Anne Helene

• Document type: Journal article
• Source: ANALYTICAL METHODS; v. 15, n. 27, p. 9-pg., 2023-06-23.

Abstract

The diffusive gradients in thin films (DGT) technique pre-concentrates labile species of trace elements, giving time-integrated in situ information about their labile concentrations. All previous DGT approaches for simultaneous uptake of cations and anions have used the hazardous polyacrylamide reagent to immobilize the binding phase. The present work proposes a diffusive layer of agarose and a mixed binding layer of ZrO2 and Chelex 100 immobilized in an agarose hydrogel to simultaneously determine the labile concentration of cations (Mn, Co, Ni, Cu, Zn and Cd) and anions (V, As, Se, Mo and Sb) in aquatic systems. The use of both layers using agarose instead of carcinogenic polyacrylamide as the hydrogel significantly reduces the costs and simplifies the manufacturing process. The proposed device was evaluated through recovery tests, deployment curves and pH/ionic strength tests. The mixed binding layer was compared with commercially available DGT devices for in situ deployment in river water. The relationships between accumulated mass and time (24 h) was linear (r(2) > 0.9) for all analytes. The diffusion coefficients obtained were consistent with the literature, ranging from 3.98 to 8.43 x 10(-6) cm(2) s(-1). Except for Zn at pH 8.0, the obtained values of C-DGT/C-bulk were within the range of 1.00 & PLUSMN; 0.2 for the studied range of pH and for most ionic strengths. However, at low ionic strength, the concentrations of Mn, Co, Ni, Zn, V and Mo were underestimated. The concentrations of trace elements determined in river water using the proposed devices agreed with the labile concentrations determined by using commercial devices. (AU)

• FAPESP's process: 18/17069-7 - Evaluation of the biogeoavailability of metals and semimetals in soils using the diffusive gradient in thin film technique
• Grantee: Amauri Antonio Menegário
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/18124-4 - Fluxes, speciation and bioavailability of arsenic at the water/sediment interface in alkaline lakes of the Pantanal of Nhecolândia using DGT
• Grantee: José Lucas Martins Viana
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 16/14227-5 - Climatic changes and environmental impacts in wetlands of Pantanal region (Brazil): quantification, control factors and long term temporal modeling
• Grantee: Adolpho José Melfi
• Support Opportunities: Research Program on Global Climate Change - Thematic Grants
• FAPESP's process: 22/00518-9 - Tracking ecosystem releases by oil and natural gas production with marine tetrapod
• Grantee: Amauri Antonio Menegário
• Support Opportunities: Regular Research Grants
• FAPESP's process: 19/07359-0 - In situ evaluation of the lability of trace metals at Pantanal of Nhecolândia, MS, Brazil, using DGT technique with mixed binding layer for simultaneouse determination of cations e anions
• Grantee: Carlos Eduardo Eismann
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 21/14272-9 - Circular economies: using DGT to assess the release kinetics of phosphorus in soils treated with waste-based fertilizer alternatives
• Grantee: José Lucas Martins Viana
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate