Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Picarro Inc., Santa Clara, CA, USA.
Environ Sci Process Impacts. 2023 Jun 21;25(6):1031-1048. doi: 10.1039/d3em00041a.
Humidity plays an important role in the surface removal and concentrations of indoor pollutants such as ozone; however, the indoor surface dynamics and chemistry of organic peroxides is largely unknown. Organic hydroperoxides (ROOHs) are known to participate in the multiphase chemistry of outdoor aerosols and clouds, suggesting that reactive uptake in condensed grime on indoor surfaces is plausible, particularly in humid homes. Here, the effect of relative humidity (RH) on the deposition velocity () and reaction probability () of a model ROOH to naturally soiled indoor glass surfaces was investigated; specifically, by using authentic isoprene hydroxy hydroperoxide (1,2-ISOPOOH) as the model compound. Glass was soiled in 3 local homes for 1+ years and characterized. The removal of ISOPOOH by soiled and clean glass was measured under 5-6%, 56-58%, and 83-84% RH conditions using a novel flow reactor designed for indoor surfaces coupled to an iodide chemical ionization high-resolution time-of-flight mass spectrometer (I-HR-TOF-CIMS). The and increased with increasing RH, ranging from 0.001-0.059 cm s and 0.4-4.6 (×10), respectively, on soiled glass surfaces. The and ranged from only 0.001-0.016 cm s and 0.1-0.8 (×10), respectively, across RH conditions on clean glass, demonstrating a greater RH effect on soiled materials than clean. Loss rates calculated under humid conditions to soiled glass (∼1-6 h) were competitive in scale with ventilation rates in typical residences, indicating the importance of surface uptake for indoor ROOH concentrations. This work provides parameters for predictive modeling of indoor ROOHs. To our knowledge, these are the first direct measurements of the of an ROOH to naturally soiled indoor surfaces.
湿度在表面去除和室内污染物（如臭氧）浓度方面起着重要作用；然而，有机过氧化物的室内表面动力学和化学性质在很大程度上是未知的。已知有机氢过氧化物（ROOH）参与户外气溶胶和云的多相化学，这表明在室内污垢凝结物中的反应性吸收是合理的，尤其是在潮湿的家中。在这里，研究了相对湿度（RH）对模型 ROOH 沉积速度（）和反应概率（）到自然污染的室内玻璃表面的影响；具体来说，使用真实的异戊二烯羟基氢过氧化物（1,2-ISOPOOH）作为模型化合物。玻璃在 3 个当地家庭中污染了 1+年，并进行了表征。使用设计用于室内表面的新型流动反应器，在 5-6%、56-58%和 83-84%RH 条件下，通过碘化物化学电离高分辨率飞行时间质谱仪（I-HR-TOF-CIMS）测量了污染和清洁玻璃对 ISOPOOH 的去除。在污染玻璃表面上，和随着 RH 的增加而增加，范围分别为 0.001-0.059 cm s 和 0.4-4.6（×10）。在清洁玻璃上，在 RH 条件下，范围分别仅为 0.001-0.016 cm s 和 0.1-0.8（×10），这表明污染材料比清洁材料对 RH 的影响更大。在潮湿条件下计算到污染玻璃的损失速率（∼1-6 h）与典型住宅中的通风速率相当，表明表面吸收对室内 ROOH 浓度的重要性。这项工作为室内 ROOH 的预测模型提供了参数。据我们所知，这是首次对自然污染的室内表面的 ROOH 进行直接测量。
