The analysis for the size-dependent chemical composition of atmospheric aerosols is useful for the recognition of their sources and behavior. In the present work, atmospheric aerosols within range of diameter 0.06-50 μm were classified into 12 fractions and chemically analyzed after separating into water-soluble and insoluble fractions. Atmospheric aerosols were collected in Nagoya by the use of a 12 stage Andersen air sampler which consists of an ordinary Andersen air sampler with 8 impactor stages joined with low pressure impactor of 4 stages for collecting of fine particles. Water soluble fractions in each sample were analyzed by inductively coupled plasma emission spectrometry (ICP-AES) for Na, Mg, Al, P, K, Ca, Ti, V, Mn, Fe, Ni, Cu, Zn, Sr, Cd, and Pb and by ion chromatography (I. C.) for NH4+. Cl-. NO3-, and SO42-. And the insoluble fractions in the samples were analyzed by ICP-AES after acid digestion with HNO3+HF+HClO4 (10 : 1 : 1 ). The following informations were obtained. (1) The characteristic peak profiles in the fine particle range of size distribution curves have been directly observed in detail for NH4+, SO42-, V, Zn, Pb, and other 9 elements. (2) The contents of the water soluble fraction of most elements in the fine particle range are higher than those in coarse particle range. (3) The profiles of size distribution curve in the total concentration of each element depend on the ralative contributions of water soluble and insoluble fractions, and the evaluation of them from both fractions by the separate-analysis will be useful for the consideration of sources and state of atmospheric aerosols.
Deposition of submicron particles in the manufacturing process of semiconductors is one of the main causes of reducing production yield. In order to suppress particle deposition onto the surface of various materials, the deposition mechanisms of submicron particles have to be well understood. In the present work, by using circular tubes made of various materials, deposition of particles in various charging states was experimentally investigated. The tube materials studied were copper, glass, polymethylmetacrylate (PMMA), polyvinylchloride (PVC), polycarbonate (PC), and polyethylene (PE). As a result it was found that 1) uncharged particle deposits by Brownian diffusion in all the tubes studied ; 2) charged particle deposits in PMMA, PVC, PC and PE tubes by Coulombic force, and that the dimensionless deposition velocity is equal to the Coulombic force parameter derived for charged particle and charged infinite flat surface. Furtller, from the measurement of time dependency of particle penetration, decay of triboelectric charge on PVC and PC tubes was found to obey the law of hyperbolic decay.
The difference in aerosol lung deposition due to animal species was investigated by relating it to their lung morphologies. 11 animal species were exposed to Cr2O3 particles and the deposited amounts of particles were determined by chemical analysis. In hens and pigeons, the particles deposited on the pleura conjugated to air sacs. Because of the pouch-like lungs of frog, the particles deposited on the inside wall of the lungs. Cr2O3 concentrations in the lungs were as follows : hen (8.4 mg/g dry wt.), mouse (7.1), mongolian gerbil (5.5), pigeon (3.8), dog (3,7), monkey (3.0), guinea pig (2.4), rat (1.9), hamster (1.6), frog (1,6) and rabbit (1.5). The difference seems to be related to the complexity of nasal cavity in each animal. Although rats and mice have similar structure of nasal cavity, Cr2O3 concentrations in their lungs are considerably different. Therefore, the aerosol deposition after inhalation is influenced not only by nasal cavity but also by respiration pattern, lung structure, etc.