The birth of the atomic absorption spectrometer and its early applications in clinical chemistry.

The first application of atomic absorption spectra to chemical analysis was made as long ago as 1860 by Gustav Robert Kirchhoff (1824-87), who demonstrated the presence of various elements in the solar atmosphere. Together with Robert Wilhelm Bunsen (181199), he showed shortly afterwards that atomic spectra, whether in emission or absorption, could be the basis of a powerful method of chemical analysis. From that time on, emission methods of spectrochem. ical analysis were gradually developed and by the mid1940s had culminated in direct-reading spectrometers, which provided simultaneous multi-element analyses at high speed in the metallurgical industries. Although the possibility of determining metals by atomic absorption spectroscopy (AAS) had been recognized by Bunsen and Kirchhoff, it was virtually ignored, probably because it was a more difficult technique and because it was not expected to give any information that could not be obtained more easily by emission measurements (1).