DEVELOPMENT OF METHODS FOR ANALYZING INORGANIC COMPONENTS IN AEROSOLS AND THEIR APPLICATION TO CHEMICAL CHARACTERIZATION OF ATMOSPHERIC AEROSOLS

利用SRX-射线微探针系统制作了用于单粒子分析的光谱显微镜。该系统包括μ-XANES的元素分析和X射线衍射仪的晶体结构分析。10keV X射线微束的空间分辨率为2-5μm，镍的最低检测下限为0.3fg。XRF产额与能量的关系使得能够用特定的XANES光谱识别从铬到锌的元素的化学状态。在μ-X-射线衍射仪中，样品通过补偿光束位移进行角度振荡，以获得单个颗粒的多个衍射率。我们还建立了AGF-Nitron双薄膜同时检测单个颗粒物中氯离子和硝酸根离子的方法，并应用该系统对在日本和韩国两个偏远地点采集的单个KOSA和非KOSA气溶胶中的超痕量元素进行了定量。结果表明，与非KOSA时期相比，KOSA事件期间土壤中的重元素(Mn、Ni、Cu、Zn)和土壤成分质量显著增加。从KOSA进入初期开始进行多次时间序列采样，用两种双薄膜方法研究了氯、硝酸盐和硫酸盐离子在单个颗粒物中的混合状态。结果表明，在2004年春季的KOSA事件中，韩国改性颗粒的形成成分主要是硫酸盐，而日本的硝酸盐是主要成分。改性颗粒物的比例随时间的推移大致呈下降趋势，同时含有氯化物和硝酸盐的颗粒物在第一次采样时所占比例最大，此后显着下降。在改性粗颗粒中，硝酸盐是主要离子，少量含有硫酸盐和硝酸盐。几乎没有检测到含有这三种离子的颗粒。

Spectromicroscopy using SR x-ray microprobe system was fabricated for single particle analysis. The system consists of elemental analysis by chemical state analysis of μ-XANES and crystal structure analysis by p,-XRD. The spatial resolution was 2-5μm and the minimum detection limit of Ni was 0.3fg for 10keV x-ray microbeam. The energy dependence of XRF yield enabled identification of the chemical states of elements from Cr to Zn with specific XANES spectra. In μ-XRD system, the sample was angularly oscillated with compensation of the beam displacements to obtain several indices of diffraction from a single particle. We have also developed a AgF-nitron double thin film method for simultaneous detection of chloride and nitrate ions in individual particles.The system was applied to quantify the ultra trace elements in the individual Kosa and non-Kosa aerosols collected at the two remote sites in Japan and Korea. We have demonstrated the remarkable mass increase of heavy elements (Mn, Ni, Cu, Zn) as well as soil components during Kosa event compared with non-Kosa period. Several time-series samplings were performed from the beginning of the Kosa incoming to investigate the mixing state of chloride, nitrate and sulfate ions in individual particles by two double thin film methods. It was revealed that sulfate constituted the majority of the formed components in the modified particles in Korea, while nitrate was the major component in Japan at Kosa event in the spring of 2004. Percentage of the modified particles roughly decreased with time and that of the particles containing both chloride and nitrate was largest at the first sampling with significant decrease after that time. In the modified coarse particles, nitrate was the dominant ions and particles containing both sulfate and nitrate were slightly detected. Particles containing all three ions were hardly detected.