Performance characteristics of diffusive gradients in thin films with a mixed-binding layer gel for the measurement of inorganic arsenic and metals

2012 ◽  
pp. 454-456
Keyword(s):  
Thin Films ◽  
Inorganic Arsenic ◽  
Performance Characteristics ◽  
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.

Performance characteristics for the measurement of Cs and Sr by diffusive gradients in thin films (DGT)

1998 ◽  
Vol 368 (3) ◽  
pp. 243-253 ◽  
Author(s):  
Ling-Yun Chang ◽  
William Davison ◽  
Hao Zhang ◽  
Mike Kelly
Keyword(s):  
Thin Films ◽  
Performance Characteristics ◽  
Diffusive Gradients

Perfluorosulfonated Ionomer-Modified Diffusive Gradients in Thin Films: Tool for Inorganic Arsenic Speciation Analysis

2008 ◽  
Vol 80 (24) ◽  
pp. 9806-9811 ◽  
Author(s):  
Jared G. Panther ◽  
Kathryn P. Stillwell ◽  
Kipton J. Powell ◽  
Alison J. Downard
Keyword(s):  
Thin Films ◽  
Arsenic Speciation ◽  
Inorganic Arsenic ◽  
Speciation Analysis ◽  
Perfluorosulfonated Ionomer ◽  
Diffusive Gradients
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