1. Towards a better understanding of ethylmercury in the environment: Addressing propylation derivatization artifact and verifying its occurrence in Chinese wetlands.
- Author
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Wu, Yurong, Liu, Guangliang, Liu, Xiaoquan, Mao, Yuxiang, Guo, Yingying, Liu, Yanwei, Zhu, Liuchao, Yin, Yongguang, Cai, Yong, and Jiang, Guibin
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WETLAND soils , *ENVIRONMENTAL sampling , *SEDIMENT sampling , *DERIVATIZATION , *SOIL sampling - Abstract
• EtHg artifact during propylation links to Hg2+ in the extract for derivatization. • CuSO 4 HNO 3 CH 2 Cl 2 extraction offers excellent EtHg recovery with minimal artifacts. • EtHg is prevalent in soils/sediments across 14 Chinese wetlands. • All Yellow River Delta samples contained MeHg, with EtHg detected in 48% of them. Ethylmercury (EtHg), similar to methylmercury (MeHg), is highly neurotoxic and bioaccumulative. Although recent studies suggested its occurrence in natural soils and sediments, the common propylation derivatization for EtHg analysis might generate EtHg artifacts, potentially leading to its overestimation in environmental samples. Furthermore, the extensive environmental prevalence of EtHg remains unverified, keeping its importance largely uncertain. This study investigated the formation of EtHg artifacts during propylation derivatization, evaluating artifacts formation and recoveries under different extraction methods with real samples, and confirmed the widespread occurrence of EtHg in Chinese wetlands. EtHg artifacts were obviously present during the propylation derivatization and strongly dependent on the levels of Hg2+ (0.1–10 ng) in the derivatization solution (R² = 0.99), accounting for 1.38–2.14% of Hg2+. CuSO 4 -HNO 3 CH 2 Cl 2 extraction (effectively removing Hg2+) combined with propylation derivatization offers excellent recovery (81–86%) and low artifacts (< LOD: 1.98 × 10−4 ng/g) for EtHg measurement in soils/sediments, with results aligning with those from online solid phase extraction-high performance liquid chromatography-inductively coupled plasma mass spectrometry (R2 = 0.99). Additionally, we observed the occurrence of EtHg in soil and sediment samples across 14 Chinese wetlands, with concentrations varying from 6.08 to 171 pg/g, similar to MeHg concentrations at some sites. EtHg positively correlates with MeHg, total Hg, and total organic carbon across all samples, indicating a possible biological formation. These findings help better understand and predict the prevalence of EtHg in wetlands and its key role in environmental Hg cycle. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2024
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