Evaluation of sorption surface materials for reactive mercury compounds
Evaluation of sorption surface materials for reactive mercury compounds
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DOI：
10.1016/j.atmosenv.2020.117836
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发表时间：
2020-12-01
影响因子：
5
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
吸附表面通常用于收集大气中的汞化合物，汞研究界使用的一系列材料具有不同的性能水平。在这里，五个聚合物为基础的膜与环境中的活性汞和比较2广泛使用的吸附表面材料：尼龙和阳离子交换膜。只有1种测试材料（聚醚砜）的性能与阳离子交换膜相似;其余测试材料吸附的汞明显较少，许多材料的空白汞含量明显高于阳离子交换膜。尼龙是唯一与热解吸分析兼容的材料，因为其余材料会发生物理降解或对分析仪产生负面影响;然而，尼龙在所有环境条件下均不适用于定量分析。对尼龙和阳离子交换膜的进一步测试表明，与高浓度的单一来源气态氧化汞化合物相比，环境中的活性汞化合物在这两种材料上更稳定。单一来源的气态氧化汞化合物在储存后不到80天的时间内就会大量损失和/或转化，而环境中的活性汞化合物在储存190天后在尼龙膜和阳离子交换膜上保持稳定。然而，最大限度地减少取样和储存时间，沿着将取样膜暴露于环境空气，以减少偏差结果是谨慎的。
Sorption surfaces are commonly used to collect atmospheric mercury compounds, with a range of materials used by the mercury research community that have different levels of performance. Here, five polymer-based membranes were loaded with ambient reactive mercury and compared to 2 widely used sorption surface materials: nylon and cation exchange membranes. Only 1 tested material, polyethersulfone, performed similarly to the cation exchange membrane; the remaining tested materials sorbed significantly less mercury, and many had significantly higher blank mercury amounts than the cation exchange membrane. Nylon was the only material that was compatible with thermal desorption analysis, as the remaining materials physically degraded or negatively affected the analyzer; however, nylon was not amenable for quantitative analyses under all ambient conditions. Additional testing of the nylon and cation exchange membrane demonstrated that ambient reactive mercury compounds were more stable on both materials than high concentrations of single-source gaseous oxidized mercury compounds. Single-source gaseous oxidized mercury compounds were significantly lost and/or transformed within less than 80 days of storage, whereas ambient reactive mercury compounds were stable on nylon and cation exchange membranes after 190 days of storage. However, minimizing sampling and storage duration, along with exposure of sampled membranes to ambient air, to reduce biasing results is prudent.