Abstract Fractionated atmospheric aerosols with sizes ranged from 0.25 μm to > 16 μm have been collected on silicon wafers using a 7-stage cascade impactor from the centre location of Jeddah city, Saudi Arabia during May 2015. Two fractionated sizes were selected in the present work, namely 0.5–0.25 μm (PM 0.5–0.25 ) and 2–1 μm (PM 2.0–1.0 ), because their mass concentrations were the most dominant. Fractionated atmospheric aerosols were examined under ultra-high vacuum environment with synchrotron radiation total reflection X-ray fluorescence (SR-TXRF) and X-ray absorption near edge structure (XANES) spectroscopy techniques at the International Atomic Energy Agency (IAEA) experimental end station operating at Elettra Sincrotrone Trieste, Italy. The mass concentrations in PM 2.0–1.0 were found greater than those within PM 0.5–0.25 material and the mass concentration ratio of PM 2.0–1.0 /PM 0.5–0.25 was reached to 2. The homogeneity in the spatial deposition of different elements in both PM 0.5–0.25 and PM 2.0–1.0 fractions was evaluated by the means of X-ray fluorescence (XRF) scanning. XANES showed us that Cr species exist mainly in the trivalent oxidation state, while for Mn the co-existence of both the divalent and trivalent oxidation states was determined. The results of the present study provide an improved understanding on the origin of Cr and Mn species in these two fractionated particulates and give an insight to their contribution to atmospheric and physicochemical processes.

中文翻译：

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从沙特阿拉伯吉达收集的分馏空气颗粒的同步辐射全反射 X 射线荧光 (SR-TXRF) 和 X 射线吸收近边缘结构 (XANES)

摘要 2015 年 5 月，在沙特阿拉伯吉达市的中心位置，使用 7 级级联撞击器在硅片上收集了尺寸范围从 0.25 μm 到 > 16 μm 的分馏大气气溶胶。本工作选择了两种分馏尺寸，即 0.5–0.25 μm (PM 0.5–0.25 ) 和 2–1 μm (PM 2.0–1.0 )，因为它们的质量浓度是最主要的。在国际原子能机构 (IAEA) 实验终端站使用同步辐射全反射 X 射线荧光 (SR-TXRF) 和 X 射线吸收近边结构 (XANES) 光谱技术在超高真空环境下检查分馏大气气溶胶在意大利的 Elettra Sincrotrone Trieste 运营。发现 PM 2.0-1.0 中的质量浓度高于 PM 0.5-0 中的质量浓度。25 材料和 PM 2.0–1.0 /PM 0.5–0.25 的质量浓度比达到 2。 PM 0.5–0.25 和 PM 2.0–1.0 部分中不同元素的空间沉积均匀性通过 X 的方式进行评估-射线荧光（XRF）扫描。XANES 向我们表明，Cr 物质主要以三价氧化态存在，而对于 Mn，确定了二价和三价氧化态的共存。本研究的结果提供了对这两种分级颗粒中 Cr 和 Mn 物种起源的更好理解，并深入了解它们对大气和物理化学过程的贡献。通过 X 射线荧光 (XRF) 扫描评估 0 级分。XANES 向我们表明，Cr 物质主要以三价氧化态存在，而对于 Mn，确定了二价和三价氧化态的共存。本研究的结果提供了对这两种分级颗粒中 Cr 和 Mn 物种起源的更好理解，并深入了解它们对大气和物理化学过程的贡献。通过 X 射线荧光 (XRF) 扫描评估 0 级分。XANES 向我们表明，Cr 物质主要以三价氧化态存在，而对于 Mn，确定了二价和三价氧化态的共存。本研究的结果提供了对这两种分级颗粒中 Cr 和 Mn 物种起源的更好理解，并深入了解它们对大气和物理化学过程的贡献。