Source characterisation

Gale, N.H. (1981). Mediterranean obsidian source characterisation by strontium isotope analysis. Archaeometry 23 41-52. 

Kilikoglou, V., Bassiakos, Y., Doonan, R.C. and Stratis, J. (1997). NAA and ICP analysis of obsidian from Central Europe and the Aegean source characterisation and provenance determination. Journal of Radioanalytical and Nuclear Chemistry 216 87-93. 

Banks, D., Holden, W. et al. 2002. Contaminant source characterisation of the San Jose mine, Oruro, Bolivia. In Younger, P. L. Robins, N. S. (eds) Mine Water Hydrogeology and. Geochemistry. Geological Society Special Publication, London, 198, 215-239. 

Taylor D., Kontorovich A. E., Larichev A. I., and Glikson M. (1994) Petroleum source rocks in the Roper Group of the McArthur Basin source characterisation and maturity... 

Particles in ambient air constitute a mixture originating from different sources, and thus the individual components of the mixture are characterised by different size distributions. The measured distribution of this mixture may or may not display individual peaks from the contributing sources, and thus may or may not be used for source identification. In many cases, however, the characteristics of the size distribution can be a useful tool in source characterisation. 

The precise nature of the contaminant on the site may be important to the risk estimation. For example, the Phase lb risk assessment may have confirmed the presence of polychlorinated biphenyls (PCBs) that could reach humans. However, there is a large variation in the toxicology of individual PCB congeners and so congener-specific measurement is required for risk estimation. Total metal concentrations are sufficient to confirm the presence of a source but metal speciation may influence solubility and so the risk posed to groundwater. The choice of chemical analysis for source characterisation should be informed by... 

The second term dominates and is characterised by p = +1.30 (using a-meta constants), E = 10.8 kcal.mole , dS = —22.8 eu and k jko > 1-8. experiments show the major source of oxygen in the acid produced is the solvent, which suggests the hydrate anion is the reactive form, viz. 

The following tables are characterised by the fact that they provide all experimental values that are given by our sources for each chemical product. When several values exist for one product, they are separated by semicolons. 

J. L. Garland and A. L. Mills, Classification and characterisation of heterotrophic microbial communities on the basis of patterns of community-level sole carbon-source utilisation, Appl. Environ. Microbiol. 57 2351 (1991). 

It is equally important for the manufacturer and regulator to know the level of additives in a polymer material to ensure that the product is fit for its intended purpose. Additive analysis marks sources of supply, provides a (total) process signature and may actually be used as a fingerprint of a polymeric material, in particular as molecular characterisation of the polymer... 

DP-MS suffers from system saturation sample loads of a few ig are to be used. DP-ToFMS equipped with El and FI sources is a thermal separation technique for solids which allows exact mass determination (Section 6.3.3). In order to detect and characterise polymer fragments of higher molecular weight, techniques such as DCI, in which the sample is thermally desorbed by the filament on which it is directly deposited, and laser desorption... 

In direct insertion techniques, reproducibility is the main obstacle in developing a reliable analytical technique. One of the many variables to take into account is sample shape. A compact sample with minimal surface area is ideal [64]. Direct mass-spectrometric characterisation in the direct insertion probe is not very quantitative, and, even under optimised conditions, mass discrimination in the analysis of polydisperse polymers and specific oligomer discrimination may occur. For nonvolatile additives that do not evaporate up to 350 °C, direct quantitative analysis by thermal desorption is not possible (e.g. Hostanox 03, MW 794). Good quantitation is also prevented by contamination of the ion source by pyrolysis products of the polymeric matrix. For polymer-based calibration standards, the homogeneity of the samples is of great importance. Hyphenated techniques such as LC-ESI-ToFMS and LC-MALDI-ToFMS have been developed for polymer analyses in which the reliable quantitative features of LC are combined with the identification power and structure analysis of MS. 

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