Determination of the Isotopic Composition of Aqueous Mercury in a Paddy Ecosystem Using Diffusive Gradients in Thin Films

Measuring the isotopic composition of Hg in natural waters is challenging due to the ultratrace level of aqueous Hg (ng L-1). At least 5 ng of Hg mass is required for Hg isotopic analysis. Given the low Hg concentration in natural waters, a large volume of water (>10 L) is typically needed. The conventional grab sampling method is time-consuming, laborious, and prone to contamination during transportation and preconcentration steps. In this study, a DGT (diffusive gradients in thin films) method based on aminopropyl and mercaptopropyl bi-functionalized SBA-15 nanoparticles was developed and extended to determine the concentration and isotopic composition of aqueous Hg for the first time. The results of laboratory analysis showed that Hg adsorption by DGT induces ∼ -0.2‰ mass-dependent fractionation (MDF) and little mass-independent fractionation (MIF). The magnitude of MDF exhibits a dependence on the diffusion-layer thickness of DGT. Since Hg-MDF can occur in a broad range of environmental processes, monitoring the δ202Hg of aqueous Hg using the DGT method should be performed with caution. Field results show consistent MIF signatures (Δ199Hg) between the DGT and conventional grab sampling method. The developed DGT method serves as a passive sampling method that effectively characterizes the MIF of Hg in waters to understand the biogeochemical cycle of Hg at contaminated sites.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:95

Enthalten in:

Analytical chemistry - 95(2023), 33 vom: 22. Aug., Seite 12290-12297

Sprache:

Englisch

Beteiligte Personen:

Yin, Hongqian [VerfasserIn]
Yao, Heng [VerfasserIn]
Yuan, Wei [VerfasserIn]
Lin, Che-Jen [VerfasserIn]
Fu, Xuewu [VerfasserIn]
Yin, Runsheng [VerfasserIn]
Meng, Bo [VerfasserIn]
Luo, Jun [VerfasserIn]
Feng, Xinbin [VerfasserIn]

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Volltext

Themen:

Journal Article

Anmerkungen:

Date Revised 22.08.2023

published: Print-Electronic

Citation Status PubMed-not-MEDLINE

doi:

10.1021/acs.analchem.3c01356

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM36104366X