The Development of Atomic Absorption Spectroscopy (AAS)

The Beginnings of AAS

The basic principle of light absorption through atoms in their fundamental state was discovered and documented in 1860 by Kirchhoff and Bunsen. The discovery is considered to be the theoretical basis of AAS. However, the actual year of birth of AAS is seen as 1955. That year, British-Australian physicist and chemist Alan Walsh published the groundbreaking idea of also using the spectra for chemical analyses.

According to modern legend, the idea for AAS came to Alan Walsh while gardening. Whether that is actually true can’t really be proven today. However, the fact is that his article “The application of atomic absorption spectra to chemical analysis,” published in 1955 in Spectrochimica Acta, constituted the cornerstone of modern AAS. The method made it possible for the first time to measure the concentration of numerous elements in a cost-effective and quick manner without wet-chemical analysis methods.

Around ten years passed between the initial publication of the idea and the first flame AAS devices being available on the market. Five years later, they were followed by the first electro-thermal AAS systems with graphite furnaces.

contrAA 800 – An AAS Success Story

The devices of the contrAA series made the previously common changing of lightbulbs of conventional AAS obsolete. Now, only one light source is needed to measure all elements and analysis lines – a single xenon short arc lamp covers the entire relevant wavelength spectrum. Users can therefore switch between elements very quickly, which enables a sequential definition of multiple elements and saves a great amount of time in the analysis process. The 2D or 3D visualization of the spectrum offered by HR-CS AAS produces much more information than conventional AAS. Thanks to the high-resolution spectrometer, interferences can be immediately identified and corrected. The current devices in the contrAA 800 series combine flame and graphite furnace technologies in one flexibly expandable platform and can be easily and quickly optimized with accessories for specific applications – for example with autosamplers or systems for direct solid sample analysis.

The contrAA series has won over numerous clients thanks to these exceptional qualities. In recent years, over 1,500 devices have been installed in laboratories around the world and are used for applications in environmental analysis, food inspection, or the process and quality control in numerous industrial areas. For example, the contrAA device with flame atomization is used for the analysis of wine and fruit juice not only in Germany but also in other European countries such as Italy, Spain, and Portugal. “We have been working with the contrAA in the areas of research and routine analysis for many years,” says Dr. Claus Patz, scientist at the Department of Beverage Research of Geisenheim University, who has used the device with his team since 2009 for the mineral analysis of wines, fruit juices, and other beverages. “We particularly appreciate the flexible application, since every wavelength is available and even molecule bands can be measured.”

 _{(Image of Sir Alan Walsh (1916-1998) by CSIRO)}