Abstract. Atmospheric mercury speciation is of paramount importance for understanding the behavior of mercury once it is emitted into the atmosphere as gaseous elemental (GEM), gaseous oxidized (GOM) and particulate-bound (PBM) mercury. GOM and PBM sampling are the most problematic steps in the analytical procedure. GOM sampling with speciation traps composed of KCl sorbent materials and KCl trapping solutions are commonly used sampling methods, although the work done at ambient air concentrations is limited. The results of the specificity test showed that the KCl sorbent traps are very specific when using new traps, while their specificity drops dramatically when they are reused. The results of the stability test showed that the highest Hg²⁺ losses (up to 5.5 % of Hg²⁺ loss) occur when low amounts of Hg²⁺ (< 1 ng) are loaded, due to a reduction of Hg²⁺ to Hg⁰. GOM losses should be taken into account when using KCl sorbent traps for atmospheric Hg speciation, especially at low ambient GOM concentrations. KCl trapping solutions have also been considered as a selective trapping media for GOM in atmospheric samples. A dimensionless Henry’s law constant was experimentally derived and was used to calculate the solubility of elemental Hg in KCl solution. The degree of GEM oxidation was established by purging elemental Hg calibration gas into a KCl solution and determining the GOM trapped using aqueous phase propylation liquid-liquid extraction GC-AFS. A positive GOM bias was observed due to the solubility and oxidation of GEM in KCl trapping solutions strongly suggesting that this approach is unsuitable for atmospheric mercury speciation measurements.

中文翻译：

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用于大气汞形态形成的 KCl 吸附剂捕集剂和 KCl 捕集溶液的行为：稳定性和特异性

摘要。大气汞形态对于了解汞以气态元素 (GEM)、气态氧化 (GOM) 和颗粒结合 (PBM) 形式排放到大气中后的行为至关重要。GOM 和 PBM 采样是分析过程中最有问题的步骤。使用由 KCl 吸附剂材料和 KCl 捕集溶液组成的形态捕集器的 GOM 采样是常用的采样方法，尽管在环境空气浓度下所做的工作是有限的。特异性测试结果表明，KCl 吸附剂捕集阱在使用新捕集阱时具有很高的特异性，而在重复使用时其特异性会急剧下降。稳定性测试的结果表明，最高的 Hg ²⁺损失（高达 5.5 % 的 Hg ²⁺损失）在加载少量 Hg ²⁺ (< 1 ng) 时发生，因为 Hg ²⁺减少到 Hg ⁰. 当使用 KCl 吸附剂捕集器进行大气汞形态分析时，尤其是在低环境 GOM 浓度下，应考虑 GOM 损失。KCl 捕集溶液也被认为是大气样品中 GOM 的选择性捕集介质。无量纲亨利定律常数是通过实验推导出来的，用于计算元素 Hg 在 KCl 溶液中的溶解度。GEM 氧化的程度是通过将元素 Hg 校准气体吹扫到 KCl 溶液中并使用水相丙基化液-液萃取 GC-AFS 测定捕获的 GOM 来确定的。由于 GEM 在 KCl 捕集溶液中的溶解性和氧化性，观察到正 GOM 偏差强烈表明这种方法不适合大气汞形态测量。