Chemical Properties of the Individual Asian Dust Particles Clarified by Micro-PIXE Analytical System

• Main Authors: Chang-Jin Ma, Gong-Unn Kang, Mikio Kasahara, Susumu Tohno
• Format: Article
• Language: English
• Published: Asian Association for Atmospheric Environment 2014-09-01
• Series: Asian Journal of Atmospheric Environment
• Subjects: asian dust; aging; individual particle; long-range transport; micro-pixe
• Online Access: http://asianjae.org/_common/do.php?a=full&b=11&bidx=1556&aidx=19684

The present study was undertaken to evaluate the chemical characteristics of Asian dust (hereafter called “AD”) particles with the aid of the most advanced micro-PIXE (Particle-induced X-ray emission) analytical technique. To this end, size-selected particles were sampled on a rural peninsula of Korea (Byunsan, 35.37N; 126.27E) during AD and non-AD periods in 2004. The coarse particle (>2 μm) number density during an AD event were 170 times higher than those of the non-AD counterpart. The average net-count of silica in individual particles collected on AD event was roughly 11 times higher than that of non-AD counterpart. The X-ray net-counts of trace elements (Zn, Co, Mn, and V) were also considerably high in AD relative to the non-AD day. Particle classification based on the inter ratio analysis of elemental net-count suggests that a large portion of the coarse particles collected during AD event underwent chemical transformation to a certain degree. The visual interpretation of micro-PIXE elemental maps and elemental localization data in and/or on individual AD particles clarified the internal mixture of AD particles with sea-salt and artificial metallic particles.