大气粉尘气溶胶中铁氧化物的光谱分析

SPECTROSCOPY ANALYSIS OF IRON OXIDE IN MINERAL AEROSOLS

首次利用漫反射光谱装置(DRS)对中国大气粉尘气溶胶中铁氧化物进行了研究。结果表明,在可见光范围,粉尘样品反射光谱的一阶导数曲线,在435nm和560nm对样品中的针铁矿和赤铁矿有识别指示意义,样品中铁的含量与赤铁矿和针铁矿的一阶导数峰值相关性良好。同时发现,红、橙、黄3种颜色的反射率随样品中铁含量的增加而增加,而紫、绿、蓝3种颜色的反射率随样品中铁含量的增加而减少,这表明铁氧化物在粉尘气溶胶对可见光的散射和吸收效应中扮演着重要的角色。

It is the first time to investigate the composition and the reflectance characteristics of mineral aerosols in China using diffuse reflectance spectrometry (DRS). The result shows the first derivatives of the spectra were referred to signals of ironoxide minerals, hematite and goethite, at 560 and 435 nm. The spectra and peaks were highly correlated to the iron concentrations on the aerosol filters. And reflectivity of the yellow, orange and red bands rose with the increase of iron concentrations while that of the violet, blue and green bands decreased accordingly. We also found that the first derivative values at 560 and 435 nm were strongly related to the iron concentrations in the dust samples, which indicates ironoxide minerals play an important role in the aerosol light scattering and absorbing effects.