Department of Chemistry and Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA.
Indoor Air. 2020 Sep;30(5):914-924. doi: 10.1111/ina.12662. Epub 2020 Mar 18.
Indoor surfaces are known to support organic films, but their thickness, composition, and variability between environments remain poorly characterized. Alkenes are expected to be a significant component of these films, with the reaction with O being a major sink for O and source of airborne chemicals. Here, we present a sensitive, microscale, nanospectrophotometric method for quantifying the alkene (C=C bond) content of surface films and demonstrate its applicability in five studies relevant to indoor air chemistry. Collection efficiencies determined for a filter wipe method were ~64%, and the overall detection limit for monoalkenes was ~10 nmol m . On average, painted walls and glass windows sampled across the University of Colorado Boulder campus were coated by ~4 nm thick films containing ~20% alkenes, and a simple calculation indicates that the lifetime for these alkenes due to reaction with O is ~1 hour, indicating that the films are highly dynamic. Measurements of alkenes in films of skin oil, pan-fried cooking oils, a terpene-containing cleaner, and on various surfaces in a closed classroom overnight (where carboxyl groups were also measured) provided insight into the effects of chemical and physical processes on film and air composition.
室内表面已知会支持有机薄膜，但它们的厚度、组成和环境之间的可变性仍然描述不足。烯烃预计将是这些薄膜的重要组成部分，与 O 的反应是 O 的主要汇和空气传播化学物质的来源。在这里，我们提出了一种灵敏的、微观的、纳米分光光度法，用于定量表面薄膜中的烯烃（C=C 键）含量，并在与室内空气化学相关的五项研究中证明了其适用性。对于过滤擦拭法确定的收集效率约为 64%，单烯烃的总检测限约为 10nmol/m。平均而言，在科罗拉多大学博尔德分校校园内采集的油漆墙壁和玻璃窗被约 4nm 厚的薄膜覆盖，其中含有约 20%的烯烃，一个简单的计算表明，由于与 O 的反应，这些烯烃的寿命约为 1 小时，这表明这些薄膜具有高度的动态性。对皮肤油、煎炒食用油、含萜烯清洁剂的薄膜中的烯烃以及在封闭教室过夜的各种表面（也测量了羧基）的测量，深入了解了化学和物理过程对薄膜和空气组成的影响。
