Ultraviolet spectrophotometry analytical chemistry applications

Upstone SL. Ultraviolet/visible light absorption spectrophotometry in clinical chemistry. In Meyers RA, ed. Encyclopedia of analytical chemistry Applications, theory, and instrumentation. New York John Wiley Sons, 2000 1699-713. 

Frequently industrial hygiene analyses require the identification of unknown sample components. One of the most widely employed methods for this purpose is coupled gas chromatography/ mass spectrometry (GC/MS). With respect to interface with mass spectrometry, HPLC presently suffers a disadvantage in comparison to GC because instrumentation for routine application of HPLC/MS techniques is not available in many analytical chemistry laboratories (3). It is, however, anticipated that HPLC/MS systems will be more readily available in the future ( 5, 6, 1, 8). HPLC will then become an even more powerful analytical tool for use in occupational health chemistry. It is also important to note that conventional HPLC is presently adaptable to effective compound identification procedures other than direct mass spectrometry interface. These include relatively simple procedures for the recovery of sample components from column eluate as well as stop-flow techniques. Following recovery, a separated sample component may be subjected to, for example, direct probe mass spectrometry infra-red (IR), ultraviolet (UV), and visible spectrophotometry and fluorescence spectroscopy. The stopped flow technique may be used to obtain a fluorescence or a UV absorbance spectrum of a particular component as it elutes from the column. Such spectra can frequently be used to determine specific properties of the component for assistance in compound identification (9). 

Blinn and Gunther (1963) have reviewed the use of infrared and ultraviolet spectrophotometry in the field of pesticide residue chemistry. Spectrophotometric measurements offer several unique advantages to the analytical chemist the radiation which is absorbed is characteristic of the material doing the absorbing the degree of absorption of radiation is directly proportional to the concentration of the material in solution and spectrophotometric methods are usually essentially nondestructive to the absorbing material and therefore allow recovery for further scrutiny by other types of instrumentation when applicable. 

The applications of quantitative, ultraviolet-visible absorption methods not only are numerous but also touch on every field that requires quantitative chemical information. The reader can obtain a notion of the scope of spectrophotometry by consulting the scries of review articles that were published in Analytical Chemistry S as well as monographs on the subject."... 

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