Development and application of diffusive gradients in thin films for determining inorganic arsenic concentrations in natural waters

2006 ◽  
Vol 25 (S1) ◽  
pp. 206-206
Author(s):  
Jared G. Panther ◽  
Alison J. Downard ◽  
Kip J. Powell
Keyword(s):  
Thin Films ◽  
Natural Waters ◽  
Inorganic Arsenic ◽  
Diffusive Gradients

Contribution of organic arsenic species to total arsenic measurements using ferrihydrite-backed diffusive gradients in thin films (DGT)

2012 ◽  
Vol 9 (1) ◽  
pp. 55 ◽  
Author(s):  
Heléne Österlund ◽  
Mikko Faarinen ◽  
Johan Ingri ◽  
Douglas C. Baxter
Keyword(s):  
Thin Films ◽  
Natural Waters ◽  
Arsenic Speciation ◽  
Inorganic Arsenic ◽  
Speciation Analysis ◽  
Arsenic Species ◽  
Future Studies ◽  
Organic Arsenic ◽  
Arsenic Determination ◽  
Diffusive Gradients

Environmental contextBoth the mobility and toxicity of arsenic in natural waters are related to the aqueous species distribution. Passive sampling using ferrihydrite-backed diffusive gradients in thin films (DGT) devices has in previous studies been characterised to measure labile inorganic arsenic, and the possible contribution of organic species has been disregarded. This study shows that the two most prevalent organic arsenic species might be included in DGT measurements, which should be taken into consideration when evaluating DGT data in future studies. AbstractIn previous publications discussing arsenic determination using ferrihydrite-backed diffusive gradients in thin films (DGT) devices, organic arsenic forms have been disregarded, even though it is known that the two most prevalent in natural waters, dimethylarsinate (DMA) and monomethylarsonate (MMA), may adsorb to ferrihydrite and thereby be included in the measurement. In this work the accumulation of DMA and MMA, as well as inorganic arsenite and arsenate, to ferrihydrite-backed DGT devices was investigated. It could be demonstrated that MMA, and under acidic conditions also DMA, adsorbed to the binding layer and might therefore contribute to the total mass of measured arsenic. Diffusion coefficients were measured for all four species to enable quantification of DGT-labile concentrations of organic and inorganic arsenic. Elution of the analytes from the ferrihydrite binding layer was performed using 1 mL of 1 M NaOH to facilitate arsenic speciation analysis using chromatographic separation. Average recovery rates were between 87 and 108 %. This study shows that the contribution of DMA and MMA to the total accumulated mass must be taken into consideration when evaluating DGT data in future studies.

scholarly journals In Situ Measurement of Thallium in Natural Waters by a Technique Based on Diffusive Gradients in Thin Films Containing a δ-MnO2 Gel Layer

2018 ◽  
Vol 91 (2) ◽  
pp. 1344-1352 ◽  
Author(s):  
Hongmei Deng ◽  
Mengting Luo ◽  
Xinyao Shi ◽  
Paul N. Williams ◽  
Kexin Li ◽  
...  
Keyword(s):  
Thin Films ◽  
Natural Waters ◽  
In Situ Measurement ◽  
Gel Layer ◽  
Diffusive Gradients

scholarly journals Progress in understanding the use of diffusive gradients in thin films (DGT) – back to basics

2012 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
William Davison ◽  
Hao Zhang
Keyword(s):  
Thin Films ◽  
Natural Waters ◽  
Kinetic Studies ◽  
Simple Equation ◽  
Charge Effects ◽  
The Past ◽  
Soils And Sediments ◽  
Rate Of Reaction ◽  
Simple Equations ◽  
Diffusive Gradients

Environmental contextIt is now nearly 20 years since the introduction of the technique of diffusive gradients in thin films, which can provide information on solute concentrations and dynamics in sediments, soils and water. The interpretation of these measurements in terms of concentrations relies on simple equations and associated assumptions. This review examines how well they have stood the test of time. AbstractDiffusive gradients in thin films (DGT) is now widely used to measure a range of determinands in waters, soils and sediments. In most cases the mass accumulated is interpreted in terms of a labile form of the component being measured using a simple equation that applies to steady-state conditions. During the past decade several publications have revealed phenomena that question some of the assumptions necessary for use of the simple equation. This review systematically examines the available evidence relating to appropriate geometry, possible charge effects, binding of solutes and ligands to the diffusive gel and filter, the rate of reaction with the binding layer, the effects of solution complexation and kinetic limitation, necessary time for deployment and the measurement of nanoparticles. DGT emerges as a robust monitoring tool for labile components in solution. Although there is evidence, for some conditions, of binding of metals and, more moderately, humic substances to the diffusive gel and filter membrane, this is unlikely to affect DGT measurement in natural waters for deployment times exceeding a few days. Detailed speciation and kinetic studies require a more thorough interpretation of the mass accumulated by DGT. A coherent theory has emerged for relatively simple solutions, but systems with complex heterogeneous ligands, as is the case for natural waters, are challenging. The size discrimination of DGT is still poorly known. Systematic measurements with well characterised nanoparticles are required to define the distribution of pore sizes in the gels and to establish the contribution of natural colloids to the DGT measurement.

Development of the diffusive gradients in thin films technique (DGT) for platinum (Pt), palladium (Pd), and rhodium (Rh) in natural waters

Talanta ◽  
2019 ◽  
Vol 203 ◽  
pp. 34-48 ◽  
Author(s):  
Ehab Abdulbur-Alfakhoury ◽  
Steve Van Zutphen ◽  
Martine Leermakers
Keyword(s):  
Thin Films ◽  
Natural Waters ◽  
Diffusive Gradients

Development and application of the diffusive gradients in thin films technique for the measurement of total dissolved inorganic arsenic in waters

2008 ◽  
Vol 622 (1-2) ◽  
pp. 133-142 ◽  
Author(s):  
Jared G. Panther ◽  
Kathryn P. Stillwell ◽  
Kipton J. Powell ◽  
Alison J. Downard
Keyword(s):  
Thin Films ◽  
Inorganic Arsenic ◽  
Dissolved Inorganic Arsenic ◽  
Diffusive Gradients

Development of the Diffusive Gradients in Thin Films Technique for the Measurement of Labile Gold in Natural Waters

2012 ◽  
Vol 84 (16) ◽  
pp. 6994-7000 ◽  
Author(s):  
Andrew Lucas ◽  
Andrew Rate ◽  
Hao Zhang ◽  
S. Ursula Salmon ◽  
Nigel Radford
Keyword(s):  
Thin Films ◽  
Natural Waters ◽  
Diffusive Gradients

Measurement of Stable and Radioactive Cesium in Natural Waters by the Diffusive Gradients in Thin Films Technique with New Selective Binding Phases

2009 ◽  
Vol 81 (14) ◽  
pp. 5889-5895 ◽  
Author(s):  
Weijia Li ◽  
Feiyue Wang ◽  
Weihua Zhang ◽  
Douglas Evans
Keyword(s):  
Thin Films ◽  
Natural Waters ◽  
Radioactive Cesium ◽  
Selective Binding ◽  
Diffusive Gradients
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