Atomic line molecular analysis for multicomponent determinations in the gas phase

Abstract

A method to continuously monitor several molecules in the gas phase by measuring absorption in the ultraviolet and vacuum ultraviolet spectral regions is described. This approach is capable of almost simultanous monitoring even when the spectra overlap. Molecules characterized by highly structured absorption spectra, diffuse absorption spectra, or mixtures of both can be determined. Good agreement between experimental measurements and samples of known concentration was obtained. Special light sources that emit strong atomic and ionic lines in this wavelength region were constructed and are important in achieving the high sensitivities that were observed. A method of checking for the presence of interferents and improving specificity by using measurements at several wavelengths for one molecule is described. This technique can easily be applied to on-line process control and provides almost real time analysis.