Comparison and calibration of methods for ambient reactive mercury quantification
Comparison and calibration of methods for ambient reactive mercury quantification
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环境活性汞定量方法的比较和校准
DOI：
10.1016/j.scitotenv.2022.159219
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发表时间：
2023
影响因子：
9.8
通讯作者：
Gustin, Mae Sexauer
中科院分区：
文献类型：
--
作者：
Dunham-Cheatham, Sarrah M.;Lyman, Seth;Gustin, Mae Sexauer
气态氧化汞(GOM)是大气汞(Hg)在生态系统中沉积和隔离的主要形式。因此，需要对GOM进行准确、校准的测量。本文采用两种活性膜收集系统(RMA)测定GOM和颗粒结合汞(PBM)以及活性汞(Rm=GOM+PBM)，并与两种双通道系统(DCS)和Tekran 2537/1130形态分析系统进行了比较。集散控制系统使用气态元素汞(GEM)和总气态汞的浓度，通过差值测量操作定义的GOM。其中一个分布式控制系统连接到一个定制的自动校准系统，该系统渗透到GEM、HgBr2或HgCl2中。这五个系统放在一起为期一年，以开发一个数据集，以便了解每个系统的限制，并评估测量精度和校准器的长期精度。Tekran系统测量的GOM约占其他系统测量的GOM的14.5%。USU、UNR和RMAS之间存在显著相关性，但DCS值分别比RMAS高50%和30%。校准器在现场和实验室中表现稳定，集散控制系统完全恢复了校准器注入的GOM。由于未校准的集散控制系统测量的浓度与校准的集散控制系统相同，因此它们都是测量RM和/或GOM的准确方法。RMAS膜发生了一些损失。同步使用膜和两个双通道系统精确和校准了大气活性汞的测量。
Gaseous oxidized mercury (GOM) is the dominant form of atmospheric mercury (Hg) deposited and sequestered within ecosystems. Thus, accurate, calibrated measurements of GOM are needed. Here, two active membrane-based collection systems (RMAS) were used to determine GOM and particulate-bound Hg (PBM), as well as reactive Hg (RM = GOM + PBM), and compared with two dual-channel systems (DCS) and a Tekran 2537/1130 speciation system. The DCS measured operationally defined GOM by difference, using concentrations of gaseous elemental Hg (GEM) and total gaseous Hg. One DCS was linked to a custom-built, automated calibration system that permeated GEM, HgBr2, or HgCl2. The five systems were co-located for one-year to develop a dataset that would allow for understanding limitations of each system, and assessing measurement accuracy and long-term precision of the calibrator. The Tekran system measured ~14.5 % of the GOM measured by the other systems. The USU and UNR DCS and RMAS were significantly correlated, but the DCS was 50 and 30 % higher, respectively, than the RMAS. The calibrator performed consistently in the field and lab, and the DCS fully recovered GOM injected by the calibrator. Since the uncalibrated DCS measured the same concentrations as the calibrated DCS, they are both accurate methods for measuring RM and/or GOM. Some loss occurred from the RMAS membranes.SynopsisAccurate and calibrated measurements of atmospheric reactive mercury using membranes and two dual-channel systems.