Aerosol particles inorganic fraction

Addition of EGA to the analysis of atmospheric aerosol particles has permitted an independent speciation and determination of the nitrogenous component for samples which have not had chemical or physical pretreatment. The discovery from ESCA analyses that a substantial fraction of the particulate nitrogen exists chemically bound to the carbonaceous fraction has been confirmed by EGA. The indication from ESCA and EGA that inorganic sulfate... 

Continental aerosol particles contain a significant fraction of minerals. The insoluble fraction consists mainly of the major crustal elements silicon, aluminum and trivalent iron, which occur as alumino-silicates, quartz, and iron oxides. Elements that are eluted from minerals by water are sodium, potassium, calcium (inpart), and magnesium. The water-soluble inorganic salt ftaction is dominated by am-monimn sulfate. Again, sulfate arises from the oxidation of sulfur dioxide, both by gas-phase and by aqueous phase reactions. Whereas the mineral components are mainly found in the coarse particle size range, ammonium sulfate resides mainly in the accumulation mode. Nitrate occurs partly in association with ammoniirm in the accumulation mode, and partly together with sodiirm and other cations in the coarse particle mode. Thus, nitrate often shows a bimodal size distribution. 

Fig. 6a Abundance plots constructed for the 4 classes of particles identified by EPXMA analysis for summer (left) and winter (right) airborne particulate matter collected at the Alhambra museum. Aerodynamic diameter (dj size fractions between 0.25 and 16 pm correspond to the stages of the May impactor. For each size fraction in the abundance plot, the total number of analysed particles (N) is indicated on top of the corresponding column. SIA indicates secondary inorganic aerosol particles.

Mermet et al. [72] have systematically studied LA-ICP-AES of metallic additives in polymers, i.c. PE/(Ca, Sn, Ti) and PVC/(Ca, Sn, Ti). In this fundamental study particular attention was paid to crater and aerosol particle characteristics, LOD, matrix effects by polymer type and chemical nature of the additives, fractionation and composition of vapour fraction. The characteristics of the crater generated and the aerosol depend on the polymer nature. The ablation mechanisms for PVC and PE are quite different. LOD is related to both the polymer and additive chemical form, thus requiring an internal standard (IS). Carbon is not a good IS for some inorganic elements [72,83,85,86]. 

Carbonaceous materials (predominantly found in the fine size mode) and sometimes the dominant fraction of the total fine particle mass (Andrews et al., 2000 Putaud et al., 2004) have been usually classified as organic carbon (OC), elemental carbon (EC), and inorganic carbon (IC). The latter fraction typically consists of mineral carbonates derived almost exclusively from soil dust (Seinfeld and Pankow, 2003). Since mineral carbonates are commonly discarded from chemical aerosol mass closures, data on total carbon (TC) content of air particulate matter at sites representing different pollution levels refers only to the sum of OC and EC... 

As noted in the previous chapter, respiratory uptake of Pb entails both a deposition step for Pb-bearing inhaled aerosols and an uptake step in the pulmonary tract, the uptake rate being a function of particle size and chemical composition. The lEUBK model employs a 30% deposition of Pb in the lung, and assumes there is 100% uptake of that fraction. Given the very low uptake of divalent inorganic lead from skin surfaces, a dermal uptake component is not included in this model. 

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