Particles atmosphere

Fig. 5. Size distributions of atmospheric particles ia (—) urban, (------) mral, and (------) remote background areas.

DETERMINATION OF HEAVY METALS IN ATMOSPHERIC PARTICLES (PM 10 PM 2.5) BY ELECTROTHERMAL ATOMIC ABSORPTION SPECTROMETRY... 

In this work, atmospheric particles (PM 10 and PM 2.5) were collected by a dichotomos air sampler. Several leaching procedures were investigated for decomposition of heavy metals. The digests were pre-concentrated with sodium diethyldithiocarbamate. The determinations were canted out on a Vartan Model AA-220 atomic absorption spectrometer. The instrarment was equipped with a GTA-110 graphite furnace system. Table 1 shows the concentrations of heavy metals associated with PM 10 and PM 2.5 particles. Table 1. Concentrations of heavy metals in PM 10 and PM 2.5 atmospheric particles (ng/m )... 

Studies of atmospheric particles show that their distribution is often birno-dal i.e., the particles are made up of rwo separate fractions, one with fine and one with coarse particles (Fig. 9.1). The coarse particles, from about 2.5 pm upward, are made up of natural dust from the effect of wind, erosion, plants, volcanoes, etc. The finer fraction is made up of particles smaller than 2.5 pm and consists primarily of particles from human activity, combustion, traffic, and processes. 

Despite the difficulties, there have been many efforts in recent years to evaluate trace metal concentrations in natural systems and to compare trace metal release and transport rates from natural and anthropogenic sources. There is no single parameter that can summarize such comparisons. Frequently, a comparison is made between the composition of atmospheric particles and that of average crustal material to indicate whether certain elements are enriched in the atmospheric particulates. If so, some explanation is sought for the enrichment. Usually, the contribution of seaspray to the enrichment is estimated, and any enrichment unaccounted for is attributed to other natural inputs (volcanoes, low-temperature volatilization processes, etc.) or anthropogenic sources. 

Combustion processes are a major source of particles emitted to the atmosphere. Particles formed in combustion systems fall roughly into... 

The occurrence of C and C9 dicarboxylic acids in samples of atmospheric particles and in recent sediments (Stephanou 1992 Stephanou and Stratigakis 1993) has been attributed to photochemical degradation of unsaturated carboxylic acids that are widespread in almost all biota. 

W. Van Borm, Source Apportionment of Atmospheric Particles by Electron Probe X-ray Microanalysis and Receptor Models. Doctoral Thesis, University of Antwerp, 1989. 

Interphase Material Transfer. In some cases there is unidirectional bulk transfer of material and associated chemical between compartments (e.g. sediment deposition or atmospheric particle fallout) in which case the rate is given by an expression similar to that for advection in which Gg (m3/h) is the rate of transfer of the material namely... 

The use of materials such as asbestos in buildings and machinery is now largely discontinued, but poses a health hazard when the material is disturbed. Recognition of the importance of atmospheric particles is reflected in a dedicated volume in this series [3]. In this chapter we emphasise the interaction with the biosphere. 

Harrison, R. M. and van Grieken, R. E. eds. (1998). Atmospheric Particles. Vol. 5, IUPAC Series on Analytical and Physical Chemistry of Environmental Systems, Series eds. Buffle J. and van Leeuwen, H. P., John Wiley Sons Ltd, Chichester, UK. 

Edited by Pan M. Huang, Nicola Senesi and Jacques Buffle Atmospheric Particles Vol. 5 (1998)... 

Nitrophenols in fog and atmospheric particles were determined by GC of the underiva-tized compounds and their corresponding acetate esters. Four fused-silica columns were used with three alternative detection modes, namely mass-selective detection, nitrogen-specific detection and ECD. GC-ECD of the acetate derivatives gave the best results501. A capillary GC-UVD method was developed for the determination of small amounts of nitrophenols present in the environment. The method was compared with HPLC-UVD from the point of view of selectivity and sensitivity. LOD for GC were about one-tenth of those for HPLC502. 

Cadle, R. D. Formation and chemical reactions of atmospheric particles. J. Colloid Interface Sci. 39 25-31, 1972. 

The sulfate and nitrate content of atmospheric particles comes primarily from the conversion of sulfur dioxide and nitrogen dioxide. Photochemi-cally initiated atmospheric reactions and transient free radicals are... 

Saxena, P. and Elildemann, E.M. Water-soluble organics in atmospheric particles a critical review of the literature and application of thermodynamics to identify candidate compounds, J. Atmos. Chem., 24(1) 57-109, 1996. 

Sampling of these substances has been carried out following three approaches liquid absorbents [47], solid-phase microextraction (SPME) fibres [43] and filter substrates (mostly quartz fibre filters but also PTFE membranes [1, 42, 48, 49]). When filter substrates are used, atmospheric particles are collected over 24-h periods using high-volume (dichotomous or single-filter instruments [1, 48]), medium-volume or low-volume samplers (operated to ensure collection of sufficient aerosol mass [37, 50]). Samples were always stored at low temperamres (refrigerated or frozen) to ensure sample preservation. 

Barringer, A.R. 1973b. Method and apparatus for sensing substances by analyses of adsorbed matter associated with atmospheric particles. US Patent No. 3768302... 

Cluster Analysis of Chemical Compositions of Individual Atmospheric Particles Data... 

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