Ultraviolet spectrophotometry (Forensic Science)
Ultraviolet (UV) spectrophotometry is a nondestructive, sensitive technique that measures light absorbed by a sample in the ultraviolet spectral region. UV spectrophotometry has two general uses in forensics: screening and quantitation. Although not useful as a confirmatory test, UV spectrophotometry is a good preliminary screening method to identify classes of organic compounds with aromatic rings or conjugated systems. These structural features are common in many types of drugs and other controlled substances and in many materials used in explosives.
UV spectrophotometry can be used as a screening tool to identify a class or group of compounds in a sample. Although scientists can determine the presence or absence of suspected compounds using this technique, UV spectrophotometry has limited specificity because structurally related compounds can generate similar spectra. Many compounds, including various drug groups, produce characteristic spectra, but these spectra typically do not provide enough detail for specific compound identification; they are most useful for determining a class of compounds present in a sample. UV spectrophotometry is thus most useful for single-component analysis of samples with known or suspected composition, such as pharmaceuticals.
Different compounds have varying capacities to absorb UV light, so mixtures of compounds can complicate analysis. For example, a compound that absorbs UV light strongly...
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Further Reading (Forensic Science)
Bell, Suzanne. Forensic Chemistry. Upper Saddle River, N.J.: Pearson Prentice Hall, 2006.
Houck, Max M., and Jay A. Siegel. Fundamentals of Forensic Science. Burlington, Mass.: Elsevier Academic Press, 2006.
James, Stuart H., and Jon J. Nordby, eds. Forensic Science: An Introduction to Scientific and Investigative Techniques. 2d ed. Boca Raton, Fla.: CRC Press, 2005.
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