Atomic Absorption Detection

Atomic absorption spectroscopy is a very sensitive method for the determination of the elements and, due to its high sensitivity, is particularly valuable for determining the elements at trace levels. In electrophoresis, it is employed, for example, to determine such compounds as hemoglobin, cyanocobalamine etc. In practice, the sample is vaporized and the vapour enters a flame through which light of the characteristic wavelength of the element passes and falls on a photo-electric cell. The light is generated in a special lamp unique for each element. The amount of light absorbed will be a function of the concentration of the respective element that enters the flame. The technique is virtually independent of the molecular form in which it enters the flame.

A range of different nebilizers has been developed to couple the electrophoretic flow to the atomic absorption spectrometer. As already stated, the technique is extremely sensitive and will detect as little as 1 ng of the element in the flame.