A Selective Spectral Line Modulation Technique For High Sensitivity Continuum Source Atomic Absorption Spectrometry

A selective spectral-line modulation technique for performing continuum-source atomic absorption is described and its operation discussed. In the new technique, discrete droplets of a metal salt standard solution are periodically introduced into a source modulator flame. The atom clouds produced within this flame move through the radiation path of a continuum source, thereby selectively modulating only those atomic lines characteristic of the atoms within the cloud. This combination of continuum source and source modulator flame replaces a modulated line source within an otherwise typical atomic absorption spectrometer. The system is shown to enable multi-element analysis and exhibits relative freedom from both line and broad-band spectral interferences. Analytical curves and sensitivities obtained with the system for several elements are presented. Extensions of the system and its applications are briefly discussed. (Author).