TY - JOUR

T1 - Better understanding and applications of ammonium 12-molybdophosphate-based diffusive gradient in thin film techniques for measuring Cs in waters

AU - Gorny, Josselin

AU - Gourgiotis, Alkiviadis

AU - Coppin, Fréderic

AU - Février, Laureline

AU - Zhang, Hao

AU - Simonucci, Caroline

PY - 2019/1/21

Y1 - 2019/1/21

N2 - This study deals with further and systematic laboratory evaluation of the already known ammonium 12-molybdophosphate (AMP)-diffusive gradient in thin film (DGT) method, which is used for measuring total Cs concentration in environmental waters. This study confirms that the AMP-binding gel is not stable for pH > 6. In order to reveal a potential impact of AMP degradation on DGT application, time-series experiments were performed by deploying AMP-DGT samplers in Cs-doped moderately basic soft and hard water up to total AMP-binding gel degradation (60 and 175 h of deployment time, respectively). Linear accumulation of Cs by AMP-DGT samplers was observed up to 48 and 58 h in hard and soft waters, respectively. For this deployment time range, AMP-DGT measured over 77 ± 10 and 94 ± 16% of total Cs concentration in hard and soft water, respectively. The difference in DGT response was attributed to Ca 2+ and Mg 2+ competition reducing the uptake of AMP-DGT samplers in hard water. Shrinkage of agarose-polyacrylamide diffusive gel was experimentally observed only in hard water due to more intensive AMP-binding gel degradation in hard water. Even if the AMP-DGT response was not impacted in this study, it is recommended to use agarose hydrogel as standard diffusive gel. Based on the experience obtained from this detailed validation process, the authors propose a number of key requirements that need to be considered when developing DGT devices, with testing the performance over longer deployment times being critical.  

AB - This study deals with further and systematic laboratory evaluation of the already known ammonium 12-molybdophosphate (AMP)-diffusive gradient in thin film (DGT) method, which is used for measuring total Cs concentration in environmental waters. This study confirms that the AMP-binding gel is not stable for pH > 6. In order to reveal a potential impact of AMP degradation on DGT application, time-series experiments were performed by deploying AMP-DGT samplers in Cs-doped moderately basic soft and hard water up to total AMP-binding gel degradation (60 and 175 h of deployment time, respectively). Linear accumulation of Cs by AMP-DGT samplers was observed up to 48 and 58 h in hard and soft waters, respectively. For this deployment time range, AMP-DGT measured over 77 ± 10 and 94 ± 16% of total Cs concentration in hard and soft water, respectively. The difference in DGT response was attributed to Ca 2+ and Mg 2+ competition reducing the uptake of AMP-DGT samplers in hard water. Shrinkage of agarose-polyacrylamide diffusive gel was experimentally observed only in hard water due to more intensive AMP-binding gel degradation in hard water. Even if the AMP-DGT response was not impacted in this study, it is recommended to use agarose hydrogel as standard diffusive gel. Based on the experience obtained from this detailed validation process, the authors propose a number of key requirements that need to be considered when developing DGT devices, with testing the performance over longer deployment times being critical.  

KW - AMP degradation

KW - Binding gel stability

KW - Cesium

KW - Diffusive gradient in thin film (DGT) technique

KW - Laboratory validation

KW - Time-series accumulation

U2 - 10.1007/s11356-018-3719-y

DO - 10.1007/s11356-018-3719-y

M3 - Journal article

C2 - 30465239

AN - SCOPUS:85057121602

VL - 26

SP - 1994

EP - 2006

JO - Environmental Science and Pollution Research

JF - Environmental Science and Pollution Research

SN - 0944-1344

IS - 2

ER -