Ultraviolet spectra anticipation

Question. Which low-lying states of NO would you expect to feature in the He I ultraviolet photoelectron spectrum of NO (Consider removal of an electron from only the three outermost orbitals of NO.) Indicate whether a long or short vibrational progression would be anticipated in each case. 

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). 

It was anticipated that it the absorption spectrum of HABIs could be modified so that only deep ultraviolet light would cause radical formation, the unexposed areas would be room light stable. Many HABIs were synthesized but none had the desired spectra to allow this approach to be realized. 

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