Partitioning of Ambient Organic Gases to Inorganic Salt Solutions: Influence of Salt Identity, Ionic Strength, and pH
Partitioning of Ambient Organic Gases to Inorganic Salt Solutions: Influence of Salt Identity, Ionic Strength, and pH
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DOI：
10.1029/2021gl095247
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发表时间：
2021-12
影响因子：
5.2
通讯作者：
V. Pratap;A. Carlton;A. Christiansen;C. Hennigan
中科院分区：
文献类型：
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作者：
V. Pratap;A. Carlton;A. Christiansen;C. Hennigan
大气中存在的无机盐可能会影响二次有机气溶胶的成分和丰度。在这里，我们量化了美国东部某个地点的盐特性、盐浓度（离子强度）和溶液 pH 值对环境水溶性有机气体 (WSOCg) 分配的影响。实验 pH (pH = 1–6) 和离子强度 (10−3–101 mol kg−1) 涵盖了大气颗粒、云和雾滴中发现的各种条件。氯化物盐（NaCl、NH4Cl 和 KCl）在所有离子强度 >0.005 mol kg−1 和 pH = 1.8–6 的情况下均表现出强烈的盐析效应。相比之下，硫酸盐（Na2SO4、(NH4)2SO4 和 K2SO4）会诱导盐析和盐析行为，具体取决于离子强度和 pH 值。这些结果表明，一价阳离子的影响很小，而离子强度、pH 值和阴离子特性对大气中环境有机气体的分配有很强的影响。
Inorganic salts present in the atmosphere may affect the composition and abundance of secondary organic aerosol. Here, we quantify the effects of salt identity, salt concentration (ionic strength), and solution pH on the partitioning of ambient water‐soluble organic gases (WSOCg) at a site in the eastern United States. The experimental pH (pH = 1–6) and ionic strengths (10−3–101 mol kg−1) span a wide range of conditions found in atmospheric particles, clouds, and fog droplets. Chloride salts (NaCl, NH4Cl, and KCl) exhibit a strong salting‐out effect at all ionic strengths >0.005 mol kg−1 and pH = 1.8–6. In contrast, sulfate salts (Na2SO4, (NH4)2SO4, and K2SO4) induce both salting‐in and salting‐out behaviors, depending on ionic strength and pH. These results suggest that monovalent cations have minimal effect, while ionic strength, pH, and anion identity exert strong effects on the partitioning of ambient organic gases in the atmosphere.