Comparison of 4 Methods for Measurement of Reactive, Gaseous Oxidized, and Particulate Bound Mercury
Comparison of 4 Methods for Measurement of Reactive, Gaseous Oxidized, and Particulate Bound Mercury
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DOI：
10.1021/acs.est.9b04648
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发表时间：
2019-12-17
影响因子：
11.4
通讯作者：
Zhang, Lei
中科院分区：
文献类型：
--
作者：
Gustin, Mae Sexauer;Dunham-Cheatham, Sarrah M.;Zhang, Lei
大气是（1）汞（Hg）在地球仪中传输的重要途径，（2）汞进入生态系统的重要来源。因此，了解汞的大气化学性质对于了解汞的地球化学循环及其对人类和生态系统健康的影响至关重要。过去13年的工作表明，用于测量大气汞的标准仪器不能准确地量化气态氧化汞或颗粒结合汞。本研究重点比较了四种大气汞的定量方法和汞化合物的鉴别方法。将来自Tekran 2537/1130系统和内华达州大学里诺双通道系统（DCS）的两个自动化系统的数据与来自内华达州大学里诺反应性汞活性系统（RMAS 2.0）的数据进行比较。一个RMAS 2.0包括阳离子交换膜（CEM）和尼龙膜，第二个包括CEM和尼龙膜上游的聚四氟乙烯（PTFE）膜。Tekran系统和DCS相对于使用RMAS 2.0测量的GOM浓度低估了GOM浓度。带有上游PTFE的RMAS 2.0提供了区分GOM和PBM的方法。尼龙膜的热脱附数据鉴定出存在多种GOM和PBM化合物。
The atmosphere is an important (1) pathway by which mercury (Hg) is transported around the globe and (2) source of Hg to ecosystems. Thus, understanding Hg atmospheric chemistry is critical for understanding the biogeochemical cycle and impacts to human and ecosystem health. Work over the past 13 years has demonstrated that the standard instrument used to measure atmospheric Hg does not accurately quantify gaseous oxidized mercury (GOM) or particulate bound mercury (PBM). This study focused on comparing four methods for quantifying atmospheric Hg and identifying Hg(II) compounds. Data from two automated systems, the Tekran 2537/1130 system and the University of Nevada, Reno-Dual Channel System (DCS), were compared with two University of Nevada, Reno-Reactive Mercury Active Systems (RMAS 2.0). One RMAS 2.0 included cation exchange membranes (CEMs) and nylon membranes, and the second included a polytetrafluoroethylene (PTFE) membrane upstream of the CEM and nylon membranes. The Tekran system and the DCS underestimated GOM concentrations with respect to that measured using the RMAS 2.0. The RMAS 2.0 with the upstream PTFE provided a means of distinguishing GOM and PBM. Thermal desorption of nylon membrane data identified a variety of GOM and PBM compounds present.