Organic compounds, determination atmospheric samples

Tang, H., E.A. Lewis, D.J. Eatough, R.M. Burton, and R.J. Farber. 1994. Determination of the particle size distribution and chemical composition of semi-volatile organic compounds in atmospheric fine particles with a diffusion denuder sampling system. Atmos. Environ. 28 939-947. 

Because the science of chemical oceanography is focused on distributions of chemical constituents in the sea, its evolution has been controlled to some extent by anal5dical developments. It is not our goal to dwell on analytical methods however, discoveries of new mechanisms and processes often follow the development of better techniques to make accurate measurements. Probably the most recent example has been the evolution of a variety of mass spectrometers capable of precisely determining extremely low concentrations of metals, isotopes on individual organic compounds, and atmospheric gas ratios on small samples. There have been a host of other breakthroughs that are too numerous to mention that have had a great influence on our ability to interpret the ocean s secrets. 

Concentrations of Pb(CH3)4 and other tetraalkyllead compounds in atmospheric samples, which have been measured at different locations with species specific analytical methods, are listed in Table 11. Tetraalkyllead concentrations in indoors air were found to correspond closely with those in outdoors air [24]. More data on concentrations of alkyllead compounds in ambient air have been obtained with analytical methods which measure volatile organolead compounds or total organolead [28 to 55,173]. However, these data, being based on different sampling and analytical procedures, are difficult to compare see also [56 to 64]. According to [5], the results given in [28, 29, 32, 33] are probably unreliable. In this context it has to be considered that the majority of the nonfilterable (molecular) lead seems not to be organic in nature [58, 59] recently also tri- and/or dialkyllead compounds have been determined besides Pb(CH3)4 and other tetraalkyllead compounds in both urban and rural air in the vapor phase and in atmospheric aerosols [27,174] see also [182]. For analytical procedures to determine Pb(CH3)4 in atmospheric samples, see Section 1.1.1.1.1 on p. 75. 

Organic compounds, natural, fossil or anthropogenic, can be used to provide a chemical mass balance for atmospheric particles and a receptor model was developed that relates source contributions to mass concentrations in airborne fine particles. The approach uses organic compound distributions in both source and ambient samples to determine source contributions to the airborne particulate matter. This method was validated for southern California and is being applied in numerous other airsheds. ... 

Various other workers have reported on the determination of volatile organic compounds in soils [186,187] and landfill soils [188]. Soil fumigants such as methyl bromide have also been determined by this technique [189]. Trifluoroacetic acid is a breakdown product of hydrofluorocarbons and hydrochlorofluorocarbon refrigerant products in the atmosphere and, as such, due to the known toxicity of trifluoroacetic acid, it is important to be able to determine it in the atmosphere, water and in soil from an environmental point of view [190]. In this method the trifluoroacetic acid is extracted from the soil sample by sulfuric acid and methanol, which is then followed by the derivatisation of it to the methyl ester. The highly volatile methyl ester is then analysed with a recovery of 87% using headspace gas chromatography. Levels of trifluoroacetic acid in soil down to 0.2 ng/g can be determined by the procedure. 

The presence of relatively high levels of strong organic chelators like EDTA in the water samples prompted a detailed chemical speciation study aimed at determining whether the organic compounds identified in the survey study are chelated or complexed to radionuclides. Water samples from waste trenches 19S and 27 and inert atmosphere wells WIN and W2NA were fractionated by steric exclusion chromatography and subsequently analyzed for their... 

Carbon content is obtained from CHN analysis of modified adsorbent sample. This analysis is usually based on the determination of the amount of CO2 gas produced after combustion of the sample of known weight in the oxygen atmosphere— the standard procedure for the determination of the bulk formula of organic compounds. In contrast to the organic compounds. 

McLuckey S. A., Glish K. G., Asano K. G. and Grant B. C. (1988) Atmospheric sampling glow discharge ionization source for the determination of trace organic compounds in ambient air, Anal Chem 60 2220—2227. 

Solvent extraction combined with chromatographic techniques generally is used to study organic compounds associated with the atmospheric aerosol. Combustion to C02 is additionally used to determine total organic carbon in the samples. This includes elemental carbon present as soot. Due to the limited efficiency of solvent extraction and because many compounds show-... 

The technique is very simple, fast, and does not employ any organic solvents either for sample preparation or clean-up. This makes it highly desirable because, unlike other methods, it does not release environment-polluting organic solvents into atmosphere. Thus far, the technique has been successfully applied to the determination of a wide variety of organic compounds. However, the application of SPME to determine the nitrosamines could eliminate some problems like the widespread solvent use and the lengthy and time-consuming sample preparation steps (that are common in most of the published methods in this area). 

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