The use of continuum sources in atomic absorption spectrometry (AAS) was suggested as long ago as 1962. Recently a comprehensive review was published which treated the history and the state of the art of continuum source AAS.
János Fazakas and Paul Gh. Zugrăvescu, "Sensitivity Enhancement of Electrothermal Atomic Absorption Spectrometry by Use of a Continuum Light Source and Pressurized Atomization—A Suggestion," Appl. Spectrosc. 42, 521-523 (1988)