Contamination identification

Groundwater monitoring is a necessary component in any investigation of subsurface contamination. A wide variety of information can be gleaned from the data including groundwater velocity and direction, and contaminant identification and concentration. These data can be combined with other observations to infer various characteristics of the contamination. Examples are source and timing of the release, and future location of the contaminant plume. 

California Air Resources Board, Toxic Air Contaminant Identification List Summaries, September, 1997b. 

Another type of classification is outlier selection or contamination identification. As an example, in Fig. 4.23(b), the butter is the desired material and bacteria the contamination. An arbitrary threshold for this image would be 0.02, in which all pixels >0.02 are considered suspect, and hopefully, because this is a food product, decontamination procedures are pursued. In these two examples of classification, only arbitrary thresholds have been defined and, as such, confidence in these classifications is lacking. This confidence can be achieved through statistical methods. Although this chapter is not the appropriate place for an involved discussion of application of statistics toward data analysis, we will give one example often used in chemometric classification. 

Imaging of elemental and isotopic distributions on surfaces has proved useful for diffusion measurements, corrosion and reactivity studies, contamination identification, and many other applications. SIMS imaging is particularly useful because of its high sensitivity. An example was the application to a problem in which a U-... 

Masters JR, Bedford P, Kearney A, Povey S Franks LM (1988) Bladder cancer cell line cross-contamination identification using a locus specific minisatellite probe. British Journal of Cancer 57 284-286. 

California Air Resouces Board. Toxic air contaminant identification list, www. arb. ca. gov/toxics/quickref.htm... 

The California Air Resources Board (ARB) (1989) has developed a list of substances of concern in California, called Status of Toxic Air Contaminant Identification." This list and the organization of substances within it are subject to periodic revision, as needed. The February 1989 Status List groups substances into three categories. Category I includes identified toxic air contaminants asbestos, benzene, cadmium, carbon tetrachloride, chlorinated dioxins and dibenzofurans (15 species), chromium (VI), ethylene dibromide and... 

Composition of deposited layers Thickness of deposited layers Defect characterization Particle identification Process residue identification Lubricant type and thickness Carbon overcoat composition Magnetic layer composition Magnetic layer thickness Defect/contamination identification Failure analysis... 

The practical applications of the various microscopical techniques have created opportunities for microscopists in industry and, in particular, within pharmaceutical research and development. Microscopy is used extensively, from the earliest stages of drug discovery into late development and even into manufacturing. Pharmaceutical microscopy can be conveniently divided into physico-chemical and biological applications. This chapter will consider exclusively the physico-chemical aspects of microscopy in the pharmaceutical industry. There are three broad areas in which microscopy can play an important role in the development of drugs solid-state analysis, particle size and morphology studies, and contaminant identification. This chapter presents an overview of how microscopy contributes to each of these three areas. The emphasis will be on practical examples taken from the literature and from the author s experience. 

This chapter has presented a survey of some of the ways that microscopy can aid in the development of pharmaceuticals. Microscopy can make important contributions to the solid-state characterization of the drug substance, to particle size analysis, and to contaminant identification. It is often joked, though, that the most important instrument in microscopy lies just above the eyepieces - a skilled, well-trained microscopist. It is no joke that the techniques described in... 

The present section provides an outline of the environmental forensic approach, the different types of possible contaminants released from solid wastes (disposed in landfills or recycled as road construction and repair materials), and analytical techniques and advances in contaminant identification and characterization. 

Contaminant identification was based on comparison with the GC retention times and mass fragmentation patterns of standard reference materials, and with the help of the Wiley standard library incorporated in the Chemstation data system. Molecular marker identification was achieved using various standard mixtures injected in both GC and GC-MS. 

Pharmaceutical industry Contamination identification Distribution of active ingredients in tablets Drug distribution in time-release coatings Patent infringement monitoring... 

Biotechnology Contamination identification Correlation of surface chemistry and biocompatibility Biosensor development Promotion of cell growth on surfaces... 

Deformulation Analytical Physical Testing f Failure Analysis Contaminant Identification 0 e Litigation Support... 

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