Photofragment Fluorescence as an Analytical Technique for Gas-Phase Alkali Compounds

Sensitive techniques are needed for the detection of highly corrosive gas-phase alkali compounds in the combustion of coal gas to drive gas turbines. It has been suggested1 that photofragment fluorescence, i.e., the observation of electronically excited photofragments from the photodissociation of the parent compound at suitably short ultraviolet wavelengths, would be a practical diagnostic technique. A recent investigation2 of the photodissociation of gas-phase sodium and potassium chlorides to produce excited alkali atoms has shown that the photofragment fluorescence technique can measure these compounds at concentrations down to sub-part-per-billion levels and is linear over at least six orders of magnitude. The photodissociation of other gas-phase alkali compounds has not been previously investigated.