Single-particle characterization of soil samples collected at various arid areas of China, using low-Z particle electron probe X-ray microanalysis☆

Individual soil particles collected at arid areas of China are analyzed using a single particle analytical technique, named low-Z particle electron probe X-ray microanalysis (EPMA). The major chemical species encountered in soil samples are SiO2, aluminosilicates, CaCO3, Fe-containing particles, and carbonaceous particles. Aluminosilicate particles are the most abundant in soil samples, followed by SiO2 particles. For soil samples collected at Loess plateau nearby the Yellow river, aluminosilicate and CaCO3 species are more abundantly observed than for soil samples collected at the Tengger and the Hungshandake deserts. Whereas, sand desert soils have higher content of SiO2 than loess soils. s work, using the low-Z particle EPMA, it is clearly demonstrated that the relative abundances of each chemical species significantly vary among soil samples. The frequencies to encounter aluminosilicates and the contents of minor elements in aluminosilicate-containing particles are different between soil samples. Also, the contents of calcite, dolomite, and Fe-containing particles vary from sample to sample. This kind of detailed information on chemical composition of source soils could be useful for the identification of the source region of mineral particles in aerosol samples and in the research of chemical modification of Asian Dust particles during long-range transport.