Abstract. This study investigated the effect of relative humidity (RH) on the chemical composition of gas and particle phases formed from the photooxidation of 1,3-butadiene (13BD) in the presence of NOx under acidic and non-acidic conditions. The experiments were conducted in a 14.5 m³ smog chamber operated in a steady-state mode. Products were identified by high performance liquid chromatography, gas chromatography mass spectrometry and ultrahigh performance liquid chromatography coupled with high resolution mass spectrometry. More than 48 oxygenated products were identified including 33 oxygenated organics, 10 organosulfates (OSs), PAN, APAN, glyoxal, formaldehyde, and acrolein. Secondary organic aerosol (SOA) mass and reaction products were found to be dependent on RH and acidity of the aerosol. SOA mass, and most SOA products (i) were higher under acidic than non-acidic conditions, and (ii) decreased with increasing RH. Glyceric acid, threitols, threonic acids, four dimers, three unknowns, and four organosulfates were among the main species measured either under acidic or non-acidic conditions across all RH levels. Total secondary organic carbon and carbon yield decreased with increasing RH under both acidic and non-acidic conditions. The photochemical reactivity of 13BD in our systems decreased with increasing RH and was faster under non-acidic than acidic conditions. To determine the contribution of 13BD products to ambient aerosol, we analyzed PM_2.5 samples collected at three European monitoring stations located in Poland. The occurrence of several 13BD SOA products (e.g., glyceric acid, tartronic acid, threonic acid, tartaric acid, and OSs) in the field samples suggests that 13BD could contribute to ambient aerosol formation.

中文翻译：

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1,3-丁二烯的大气氧化：酸度和相对湿度对 SOA 成分和空气有毒化合物的影响


摘要。本研究研究了相对湿度 (RH) 对酸性和非酸性条件下 NOx 存在下 1,3-丁二烯 (13BD) 光氧化形成的气相和颗粒相化学成分的影响。实验在稳态模式下运行的 14.5 m ³ 烟雾室中进行。通过高效液相色谱、气相色谱质谱和超高效液相色谱与高分辨率质谱联用对产物进行鉴定。鉴定出超过 48 种氧化产物，包括 33 种氧化有机物、10 种有机硫酸盐 (OS)、PAN、APAN、乙二醛、甲醛和丙烯醛。二次有机气溶胶 (SOA) 质量和反应产物被发现取决于气溶胶的相对湿度和酸度。 SOA 质量和大多数 SOA 产物 (i) 在酸性条件下高于非酸性条件，并且 (ii) 随着相对湿度的增加而减少。甘油酸、苏糖醇、苏糖酸、四种二聚体、三种未知物和四种有机硫酸盐是在所有 RH 水平的酸性或非酸性条件下测量的主要物质。在酸性和非酸性条件下，总次生有机碳和碳产量均随着相对湿度的增加而降低。我们系统中 13BD 的光化学反应活性随着相对湿度的增加而降低，并且在非酸性条件下比酸性条件下更快。为了确定 13BD 产品对环境气溶胶的影响，我们分析了在位于波兰的三个欧洲监测站收集的 PM _2.5 样本。现场样品中存在多种 13BD SOA 产品（例如甘油酸、丙醇二酸、苏糖酸、酒石酸和 OS），表明 13BD 可能有助于环境气溶胶的形成。