Trace elements concentration

Typically, PIXE measurements are perfonned in a vacuum of around 10 Pa, although they can be perfonned in air with some limitations. Ion currents needed are typically a few nanoamperes and current is nonnally not a limiting factor in applying the teclmique with a particle accelerator. This beam current also nonnally leads to no significant damage to samples in the process of analysis, offering a non-destmctive analytical method sensitive to trace element concentration levels. 

Figure Bl.24.15. An example of a PIXE spectmm. This spectmm was obtained from the analysis of a piece of ivory to establish whether the origm of the ivory could be detennined from trace element concentrations.

Figure 1.5. Trace element concentrations of zinc, strontium and rubidium in bone.

Pippenger, C.E., Meng, X., Stolfi, V, McGonagle, B. and Fazio, V.W. (1991). Free radical scavenging activities and trace element concentrations in erythrocytes and plasma of adult patients with inflammatory bowel disease. In Inflammatory Bowel Diseases. Progress in Basic Research and Clinical Implications (eds. H. Gocbell, K. Ewe, H. Malchow and Ch. Koelbel) p. 33. Kluwer Academic Publishers, Lancaster. 

Herber RFM (1999) Review of trace element concentrations in biological specimens according to the TRACY protocol. Int Arch Occup Environ Health 72 279-283. 

Gibs J, Szabo Z, Ivahnenko T, Wilde FD (2000) Change in field turbidity and trace element concentrations during well purging. Ground Water 38 577-588... 

The sources of uncertainty in NAA analysis are well understood, and can be derived in advance, modelled and assessed experimentally. There are two main kinds of interferences in the calculation of trace-element concentrations by INAA. The first one is formation of the same radionuclide from two different elements. Another kind of interference is from two radionuclides having very close y lines. Whenever interferences occur, the radionuclide of interest can be carried through a post-irradiation radiochemical separation without the danger of contamination. 

CPAA may be employed to determine trace element concentrations in bulk solid material, but its importance in our present context is that it permits the characterization of a thin surface layer, i.e. the mass of the analyte element per surface unit, with a good detection limit and outstanding accuracy. For example the composition of a surface layer (or foil) of known thickness can be determined, or, conversely, the thickness of a surface layer of known concentration. Depth profiling or scanning is not possible, and a disadvantage of the method is that heating occurs during irradiation. It is also not possible to discriminate between different oxidation states of the analyte element or between different compounds. 

CPAA measures the characteristic decay radiation of the radionuclides produced by the incident charged particles. The technique has been widely applied in the determination of trace elements concentrations in bulk samples, but it also has possibilities for surface characterisation, provided the thickness of the layer to be characterised is less than the range of the charged particles employed. 

The first two locations are preferred because it eliminates the need to reheat the flue gas to the reaction temperature, thereby minimizing loss of thermal efficiency. The advantages of tail-end configurations include clean flue gas (small trace element concentrations, low S02 concentrations), more space to accommodate any changes in... 

The primary sources of trace elements in soils are the parent materials from which soils are derived. These parent materials constitute the reserve for trace elements. Concentrations of trace elements in soils are directly dependent upon their abundance in the earth crust. In general, concentrations of most trace elements in global soils are from one third to three times those in the earth s crust. The logarithm ratios of their concentrations in the global soils over the earth s crust are in the range 0.5 (Fig. 2.2). 

Northern Californian soils have higher concentrations of Cr, Co, Cu and Ni than southern California since there are volcanic ultramafic rocks in northern California. Ultramafic rocks are mostly serpentine, a magnesium silicate with associated high amounts of Ni and Cr. Soils formed on serpentine parent materials contain high to extremely high Ni and Cr concentrations in soils. Soil parent material is a factor mostly controlling trace element concentrations in soils. 

Figure 7.1. Trace element concentrations in plants on California Donimo soil (pH 7.5) amended with metal sulfate-enriched sludge (Data from Mitchell et al., 1978)...

Because trace element concentrations in the soil solution of arid soils are very low, the exchangeable trace elements on various solid-phase components become important in supplying plants. Among various solid-phase components, the exchangeable trace elements are the most bioavailable... 

Bradford G.R., Page A.L., Lund L.J., Olmstead W. Trace element concentrations of sewage treatment plant effluents and sludges Their interactions with soils and uptake by plants. J Environ Qual 1975 4 123-127. 

Chopin E. I. B., Black S., Hodson M.E., Coleman M.L., Alloway B.J. A preliminary investigation into mining and smelting impacts on trace element concentrations in the soils and vegetation around Tharsis, SW Spain. Mineral Soc Great Britain Ireland 2003 67 279-288. 

Johnson C.D., Vance G.F. Long-term land application of biosolids soil and plant trace element concentrations. University of Wyoming, Cooperative Extension Service, B-1062. 1998... 

Rice K.C. Trace element concentrations in streambed sediment across the continental United States. Environ Sci Technol 1999 33 2499-2504. 

Simyu G.M., Tole M.P., Davies T.C. Trace elements concentrations in HelPs Gate National Park and health implicatins for zebra (Equus burchelli), Kenya. Retrieved Jan 2005 from www.unep.org/gef/content/pdf/34-Gelas.pdf. 

Figure 7.1. Elovich model (b), respectively. Soils were incubated under the saturation paste regime (modified after Han et al., 2002b. Reprinted from J Environ Sci Health, Part A, 137, Han F.X., Banin A., Kingery W.L., Li Z.P., Pathways and kinetics of transformation of cobalt among solid-phase components in arid-zone soils, p 192, Copyright (2003), with permission from Taylor Francis). Trace element concentrations in plants on California Donimo soil (pH 7.5) amended with metal sulfate-enriched sludge (Data from Mitchell et al., 1978).

The sorption behaviour of trace elements depends on a variety of factors which, taken together, make sorption losses rather difficult to predict. However, the data from the study and from the literature indicate for which elements sorption losses may be expected as a function of a number of factors, such as trace element concentration, container material, pH, and salinity. 

Johnson, C. A., 1986, The regulation of trace element concentrations in river and estuarine waters with acid mine drainage, the adsorption of Cu and Zn on amorphous Fe oxyhydroxides. Geochimica et Cosmochimica Acta 50, 2433-2438. 

Livingston, H.D. and G. Thompson. 1971. Trace element concentrations in some modem corals. Limnol. Ocean. 16 786-795. 

Hui, A., J.K. Takekawa, V.V. Baranyuk, and K.V. Litvin. 1998. Trace element concentrations in two subpopulations of lesser snow geese from Wrangel Island, Russia. Arch, Environ. Contam. Toxicol. 34 197-203. 

Sharif, A.K.M., A.I. Mustafa, M.N. Amin, and S. Safiullah. 1993. Trace element concentrations in tropical marine fish from the Bay of Bengal. Sci. Total Environ. 138 223-234. 

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