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 O₃ being a major sink for O₃ 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⁻². 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 O₃ 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.

中文翻译：

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室内表面上烯烃的定量及其对化学源和汇的影响。

已知室内表面可支撑有机膜，但其厚度，组成和环境之间的可变性仍然很难表征。烯烃是这些薄膜的重要组成部分，与O ₃的反应是O ₃和空气中化学品的主要吸收源。在这里，我们提出了一种敏感的，微型的，纳米分光光度法，用于量化表面膜中烯烃（C = C键）的含量，并证明了其在与室内空气化学有关的五项研究中的适用性。对于滤纸擦拭法确定的收集效率为〜64％，单烯烃的总检测限为〜10 nmol m ^-2。平均而言，整个科罗拉多大学博尔德分校采样的粉刷墙壁和玻璃窗都涂有约4 nm厚的膜，膜中含约20％的烯烃，简单的计算表明，这些烯烃与O ₃反应的寿命约为〜1小时，表明影片具有很高的动态性。对皮油，煎炸食用油，含萜烯的清洁剂以及在封闭的教室中隔夜（其中还测量了羧基）的各个表面上的烯烃进行测量，从而洞悉了化学和物理过程对薄膜的影响和空气成分。