UJF-Grenoble 1/CNRS, Laboratoire de Glaciologie et Géophysique de l'Environnement (LGGE), UMR 5183, Grenoble, F-38041, France.
Environ Sci Technol. 2011 Jun 15;45(12):5238-44. doi: 10.1021/es200587z. Epub 2011 May 16.
This work explores the heterogeneous reaction between HUmic-LIke Substances (so-called HULIS) and ozone. Genuine atmospheric HULIS were extracted from aerosol samples collected in Chamonix (France) in winter and used in coated flow tube experiments to evaluate heterogeneous uptake of O₃ on such mixtures. The uptake coefficient (γ) was investigated as a function of pH (from 2.5 to 10), O₃ concentration (from 8 to 33 × 10¹¹ molecules cm⁻³), relative humidity (20 to 65%) and photon flux (from 0 to 1.66 × 10¹⁵ photons cm⁻² s⁻¹). Reactive uptake was found to increase in the irradiated experiment with pH, humidity and photon flux. The extract was characterized before and after exposure to O₃ and/or UV light in the attempt to elucidate the effect of the photochemical aging. Carbon content measurements, UV-vis spectroscopy and functional groups analysis revealed a decrease of the UV absorbance as well as of the carbon mass content, while the functionalization rate (COOH and C═O) and therefore the polarity increased during the simulated photochemical exposure.
本工作研究了类腐殖质物质（所谓的 HULIS）与臭氧的非均相反应。从法国夏蒙尼采集的气溶胶样品中提取了真正的大气 HULIS，并将其用于涂覆流管实验中，以评估此类混合物对臭氧的非均相吸收。作为 pH 值（从 2.5 到 10）、臭氧浓度（从 8 到 33×10¹¹ 个分子 cm⁻³）、相对湿度（20 到 65%）和光子通量（从 0 到 1.66×10¹⁵ 个光子 cm⁻² s⁻¹）的函数，研究了吸收系数（γ）。发现随着 pH 值、湿度和光子通量的增加，辐照实验中的反应性吸收增加。在尝试阐明光化学老化效应的过程中，对暴露于 O₃ 和/或紫外光前后的提取物进行了特性描述。碳含量测量、紫外可见光谱和官能团分析表明，在模拟光化学暴露过程中，紫外吸收以及碳质量含量降低，而官能化速率（COOH 和 C═O）和极性增加。
