Spectroscopy light

The widely used technique of light spectroscopy has also been applied to the qual and quant detn of bound N in energetic materials. There are five distinct systems used colorimetry, infrared spectroscopy, polarimetry, Raman spec troscopy and ultraviolet spectroscopy... 

Physical chemistry involving light spectroscopy and photochemistry... 

Malley, D.F. and Nilsson, M. (1995) Fnvironmental applications of near infrared spectroscopy seeing the environment in a different light. Spectroscopy Europe 7(6), 8-16. 

In 1956 McCrone founded McCrone Associates, a private analytical laboratory in which the principal analytical technique employed was polarized light spectroscopy. Over the years he and his staff learned to visually identify over 30000 particles (McLafferty 1990). McCrone Associates speciahzed in the identification of polymorphs, asbestos samples, airborne impurities, among others. McCrone recently endowed a chair of chemical microscopy to Cornell University, his Alma Mater. 

At the end of this test, the chemist hopes that the run was a good one and that the interpretation was accurate—or that there is enough sample for another try—because this technique is a destructive technique the sample is now gone and cannot be reconstructed. Fortunately, there are other spectroscopic methods that are not as destructive. One of these is light spectroscopy. 

However, light spectroscopy, like mass spectroscopy, does not print out the name of the compound on a slip of paper and hand it to you. The way a molecule interacts with light is going to depend on the nature and arrangement of all of its pieces, so the response to light is varied and complicated. The analytical chemist can again resort to a library, but if the separation was not exactly clean and there are contaminants with their own, interfering, peaks, then more detective work remains to be done. 

Bohr s atomic model was the first to successfully account for electronic properties of atoms, specifically, the interaction of atoms and light (spectroscopy). 

Y.G. Chung, J.A. Schwartz, C.M. Gardner, R. Sawya, S.L. Jaques (1994). Fluorescence of normal and cancerous brain tissue the excitation/emission matrix. In Robert R. Alfano (Ed.), Advances in Laser and Light Spectroscopy to Diagnose Cancer and other Diseases (SPIE Proc. Vol. 2135, pp. 66-75). 

The earliest detector used for visible light spectroscopy was the human eye. There are still spectroscopes and color comparators designed for visual observation of color and intensity. 

This is why various types of light spectroscopy are so useful in chemical characterization. 

H.Z. Cummins, E.R. Pike (eds.). Photon Correlation and Light Spectroscopy (Plenum, New York, 1974)... 

The reaction between hydrogen and iodine to form hydrogen iodide was used to illustrate Beer s law in Chapter 14 (Figure 14.5). The reaction can be monitored using visible-light spectroscopy because I2 has a violet color while Hj and HI are colorless. At 300 K, the equilibrium constant for the reaction H2( ) + l2( ) 2HI( ) is = 794. 

---