Nozière Barbara, Gérard Violaine, Baduel Christine, Ferronato Corinne
CNRS, Université Claude Bernard Lyon 1, IRCELYON, F-69626;
CNRS, Université Claude Bernard Lyon 1, IRCELYON, F-69626.
J Vis Exp. 2017 Apr 21(122):55622. doi: 10.3791/55622.
Surface-active compounds, or surfactants, present in atmospheric aerosols are expected to play important roles in the formation of liquid water clouds in the Earth's atmosphere, a central process in meteorology, hydrology, and for the climate system. But because specific extraction and characterization of these compounds have been lacking for decades, very little is known on their identity, properties, mode of action and origins, thus preventing the full understanding of cloud formation and its potential links with the Earth's ecosystems. In this paper we present recently developed methods for 1) the targeted extraction of all the surfactants from atmospheric aerosol samples and for the determination of 2) their absolute concentrations in the aerosol phase and 3) their static surface tension curves in water, including their Critical Micelle Concentration (CMC). These methods have been validated with 9 references surfactants, including anionic, cationic and non-ionic ones. Examples of results are presented for surfactants found in fine aerosol particles (diameter <1 μm) collected at a coastal site in Croatia and suggestions for future improvements and other characterizations than those presented are discussed.
大气气溶胶中存在的表面活性化合物或表面活性剂，预计在地球大气中液态水云的形成过程中发挥重要作用，这是气象学、水文学以及气候系统中的一个核心过程。但由于几十年来一直缺乏对这些化合物的特定提取和表征方法，人们对它们的身份、性质、作用方式和来源知之甚少，因此无法全面了解云的形成及其与地球生态系统的潜在联系。在本文中，我们介绍了最近开发的方法，用于：1）从大气气溶胶样品中靶向提取所有表面活性剂；2）测定它们在气溶胶相中的绝对浓度；3）测定它们在水中的静态表面张力曲线，包括临界胶束浓度（CMC）。这些方法已通过9种参考表面活性剂进行了验证，包括阴离子型、阳离子型和非离子型表面活性剂。文中给出了在克罗地亚沿海站点采集的细气溶胶颗粒（直径<1μm）中发现的表面活性剂的结果示例，并讨论了未来改进的建议以及除本文介绍的表征方法之外的其他表征方法。
