Open AccessCharacterization of individual submicrometer aerosol particles collected in Incheon, Korea, by quantitative transmission electron microscopy energy‐dispersive X‐ray spectrometry
Author(s) -
Geng Hong,
Kang Sujin,
Jung HaeJin,
Choël Marie,
Kim HyeKyeong,
Ro ChulUn
Publication year - 2010
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2009jd013486
Subject(s) - aerosol , transmission electron microscopy , particle (ecology) , analytical chemistry (journal) , monte carlo method , materials science , scanning electron microscope , single particle analysis , mass spectrometry , nanoparticle , scanning transmission electron microscopy , electron , nanotechnology , chemistry , physics , geology , oceanography , statistics , mathematics , organic chemistry , chromatography , composite material , quantum mechanics
For the last decade the Monte Carlo calculation method has been proven to be an excellent tool for accurately simulating electron‐solid interactions in atmospheric individual particles of micrometer size. Although it was designed for application to scanning electron microscopy, in the present study it is demonstrated that the Monte Carlo calculation can also be applied in a quantitative single particle analysis using transmission electron microscopy (TEM) with an ultrathin window energy‐dispersive X‐ray (EDX) spectrometer with a high accelerating voltage (200 kV). By utilizing an iterative reverse Monte Carlo simulation combined with successive approximation, atomic elemental concentrations (including low‐ Z elements) of submicrometer standard particles were determined with high accuracy for electron beam refractory particles such as NaCl, KCl, SiO 2 , Fe 2 O 3 , Na 2 SO 4 , K 2 SO 4 , CaCO 3 , and CaSO 4 . On the basis of quantitative X‐ray analysis together with morphological information from TEM images, overall 1638 submicrometer individual particles from 10 sets of aerosol samples collected in Incheon, Korea, were identified. The most frequently encountered particle types are carbonaceous and (NH 4 ) 2 SO 4 /NH 4 HSO 4 ‐containing particles, followed by mineral (e.g., aluminosilicate, SiO 2 , CaCO 3 ), sea salt, K‐rich (e.g., K 2 SO 4 and KCl), Fe‐rich, fly ash, and transition or heavy‐metal‐containing (e.g., ZnSO 4 , ZnCl 2 , PbSO 4 ) particles. The relative abundances of the submicrometer particle types vary among samples collected in different seasons and also depend on different air mass transport routes. This study demonstrates that the quantitative TEM‐EDX individual particle analysis is a useful and reliable technique in characterizing urban submicrometer aerosol particles.