Trace-element analysis

Trace-element analysis of metals can give indications of the geographic provenance of the material. Both emission spectroscopy (84) and activation analysis (85) have been used for this purpose. Another tool in provenance studies is the measurement of relative abundances of the lead isotopes (86,87). This technique is not restricted to metals, but can be used on any material that contains lead. Finally, for an object cast around a ceramic core, a sample of the core material can be used for thermoluminescence dating. 

Trace-element analysis, using emission spectroscopy (107) and, especially, activation analysis (108) has been appHed in provenance studies on archaeological ceramics with revolutionary results. The attribution of a certain geographic origin for the clay of an object excavated elsewhere has a direct implication on past trade and exchange relationships. 

Trace Mercury. There are a number and variety of methods and instmments to determine trace quantities of both inorganic and organic mercury ia natural or synthetic substances (19) (see also Trace and residue analysis). Literature describiag numerous techniques and trace element analysis of a myriad of mercury-containing substances is available (20). Only the most commonly used methods are mentioned hereia. 

MATHEMATICAL BASIS AND SOFTWARE FOR SINGLE GRAIN MILLIPROBE XRF TRACE ELEMENT ANALYSIS (XRF-MP/SG) OF ACCESSORY MINERALS... 

Whenever the appropriate specimens can be prepared, this mode is normally the one preferred for trace-element analysis in geoscience, air polludon and atmospheric science, biology, medicine, water analysis, and forensic science. In this case, the ions pass through the specimen with negligible energy loss and there is minimal absorption of X rays. 

The optimal analytical GDMS instrument for bulk trace element analysis is the one providing the largest analytical signal with the lowest background signal, the fewest problems with isobaric interferences in the mass spectrum (e.g., the interference of with Fe ), and the least contamination from instrument com-... 

Table 2 Precision of trace elemental analysis of 3N5 (99.95%) and 6N (99.9999%) pure ...

Trace element analysis has become sufficiently important, especially to industrial users, that commercial laboratories specialising in trace and ultratrace elemental analysis are springing up. One such company specialises in high-resolution glow-discharge mass spectromety , which can often go, it is claimed, to better than parts per billion. This company s advertisements also offer a service, domiciled in India, to provide various forms of wet chemical analysis which, it is claimed, is now nearly impossible to find in the United States . 

Raw foods were freeze-dried and analyzed for carbon isotopes using mass spectrometry. Cooked foods were prepared following historic recipes, then were freeze-dried prior to analysis. For the trace element analysis, foods (both raw and cooked) were wet ashed using nitric acid in Teflon lined pressure vessels and digested in a CEM Microwave oven. Analysis of Sr, Zn, Fe, Ca and Mg was performed using Atomic Absorption Spectrometry in the Department of Geology, University of Calgary. 

Sandford, M.K. 1992 A reconsideration of trace element analysis in prehistoric hone. In S.R. Saunders and M.A. Katzenberg, eds.. Skeletal Biology of Past Peoples Research Methods. New York, Wiley-Liss 79-104. 

The examples discussed above suggest useful directions for future research involving trace element analysis of bones. Specifically, the effects of developmental age and other factors (e.g., porosity, mineralization) that may lead to differences in surface area of specimens should be considered. Diage-netic effects should be monitored by analysis of a suite of elements whose abundances are not controlled by dietary abundances (e.g., Mn, Zr, etc.). Finally, although alkaline elements such as Sr and Ba are most likely to reflect the Sr/Ca and Ba/Ca levels of the diet, omnivores such as humans are likely to obtain the majority of these elements from plants rather than from animals. Therefore for accmate diet reconstruction it is necessary to determine the total abundance of Ca as and the Sr/Ca and Ba/Ca ratios of the plant and animal resources that were potential dietary staples. The effects of culinary practices on elemental abundances (Burton and Wright 1995 Katzenberg et al. this volume) must also be evaluated. 

Trace Element Analysis of Geological Materials. By Roger D. Reeves and Robert R. Brooks... 

Quevauviller Ph, Maier EA, Vercoutere K, Muntau H, Griepink B (1992a) Certified reference material (CRM 397) for the quality control of trace element analysis of human hair. Fresenius J Anal Chem 343 335-338. 

Versieck j, Hoste j, Vanballenberghe L, De Kesel A, Van Renterghem DJ (1987) Collection and preparation of a second generation biological reference material for trace element analysis. J Radioanal Nucl Chem 113 299-304. 

Parr RM (1980) The reliability of trace element analysis as revealed by analytical reference materials. In Bratter P, Schramel P, eds. Trace Element Analytical Chemistry in Medicine and Biology, pp 631-655. Walter de Gruyter Co., New York. 

Stoeppler M, Vahter M (1994) Arsenic. In Herber RFM, Stoeppler M, eds. Trace element analysis in biological specimens. Elsevier, Amsterdam. 

The Promochem Group was the first international specialist supplier of certified reference materials (CRMs) and pharmaceutical reference substances used in environmental, medical and trace element analysis. Their experience provides a viewpoint that echoes, reinforces and expands on many of the trends discussed above (Jenks 1997). From the middle of the 1980 s, sales of CRM by Promochem increased between 10 % and 20 % annually, depending on the market sector and application. Since then National and International Metrology Institutes, such as the now privatized U.K. Laboratory of the Government Chemist (LGC), the European and U.S. Pharmacopoeias, the E.U. IRMM and others have recognized that efficient distribution of RMs, backed by available technical support, is as important as production and certification. Thus, they have moved to spread their influence outside their national origins. The Web and e-commerce will continue to grow as major facilitators of better information dissemination and supply of CRMs. 

Trace-elemental analysis with species selectivity... 

Table 8.10 Advantages of pressure decomposition for trace-element analysis...

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