Action spectroscopy, ultraviolet

Kirk BB, Trevitt AJ, Blanksby SJ, Tao Y, Moore BN, Julian RR (2013) Ultraviolet action spectroscopy of iodine labeled peptides and proteins in the gas phase. J Phys Chem A 117 1228-1232... 

Enjalbert Q, Brunet C, Vernier A, Allouche AR, Antoine R, Dugourd P, Lemoine J, Giuliani A, Nation L (2013) Vacuum ultraviolet action spectroscopy of polysaccharides. J Am Soc Mass Spectrom 24 1271-1279... 

Laser radiation can be obtained nowadays over a wide spectral range from the ultraviolet to the far infrared region, covering the range of optical spectroscopy. Fignre 2.4 shows schematically the spectral zones covered by different types of lasers. Although there are some specific regions in which direct laser action is not available. 

The action of all UV absorbers depends on the Lambert-Beer law, and the absorption properties of the UV absorber. The further the absorption edge extends into the near UV region, the more UV light can be filtered out. Of the four UV absorber classes shown above, the hydroxyphenylbenzotriazoles have the broadest absorption band [5.8], [5.12], In addition to thermal stability [5.12] and stability to extraction with water or organic solvents, photochemical stability is important [5.13]-[5.15], Ultraviolet reflection spectroscopy can be used to establish whether the employed UV absorber is still effective, even after several years external weathering [5.16]. 

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