Selective and simultaneous high resolution 2-D imaging of As^III, Cr^III and Sb^III and dissolved oxygen by developing a new DGT technique comprising a hybrid sensor

CRAES, State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences uses EasySensor DGT and Planar optode sensor to publish the article as below:

Highlights

•A new DGT can measure As^III, Cr^III and Sb^III selectively for speciation analysis.

•Combining DGT and LA-ICP-MS allows simultaneous 2-D imaging of the three analytes.

•Hybrid PO-DGT sensor allows simultaneous 2-D imaging of As^III, Cr^III and Sb^III and O₂

•Consumption of As^III and Sb^III appeared in rhizosphere sediment of V. natans.

•Laboratory calibration and validation of the novel DGT (HR-MPTS DGT) was performed.

Abstract

A new diffusive gradients in thin films technique (HR-MPTS DGT) with mercapto-functionalized attapulgite in a binding gel was developed for simultaneous two-dimensional (2-D) chemical imaging of As^III, Cr^III and Sb^III selectively at the submillimeter scale, combined with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis. The HR-MPTS DGT exhibited selective accumulation of As^III, Sb^III and Cr^III (> 97%), yet negligible accumulation of As^V, Sb^V and Cr^VI (< 2%). Accumulation of As^III, Cr^III and Sb^III on the binding gel had a linear relationship (R² > 0.99) with the corresponding standardized laser ablation signals, proving the feasibility of LA-ICP-MS analysis. Analysis for As^III, Cr^III and Sb^III was provided with favorable analytical precision (relative standard deviation <10%). With the purpose of evaluating the dynamics of As^III, Cr^III, Sb^III and O₂ in the rooting zone, a hybrid sensor, which comprises the HR-MPTS gel overlying an O₂ planar optode, was deployed in rhizosphere sediments. Results showed that the consumption of both As^III and Sb^III due to the oxidation extended ~4.48 mm into the sediments, which was consistent with the extension length of the oxidized sediment layers around the roots created by O₂ leakage.

Graphical abstract

Keywords

Arsenic、Chromium、Antimony、Planar optode sensor、Diffusive gradients in thin films

Writers

Ren MY, Zhong ZL, Ding SM, et., 2022. Selective and simultaneous high resolution 2-D imaging of As^III, Cr^III and Sb^III and dissolved oxygen by developing a new DGT technique comprising a hybrid sensor, Science of The Total Environment, Volume 835, 155460, ISSN 0048-9697, https: //doi.org/10.1016/j.scitotenv.2022.155460. 

Link

https://www.sciencedirect.com/science/article/abs/pii/S0048969722025566?via%3Dihub=