(AA) spectroscopy uses optical radiation and the absorption characteristics to
detect single elements contained in a sample.
The technique is based upon the
absorption of energy at elementally unique wavelengths, providing specificity for
multiple analytes. In AA, a sample
is first atomized. This is traditionally done using flame or electrothermal
atomizers. The atomized sample then is exposed to the optical light at the
predetermined wavelength specific to the analyte of interest. The absorption is
measured at each wavelength of interest using absorbance detectors. The amount of energy absorbed by an analyte at
a specific wavelength corresponds to the concentration of the element known to
be excited by that wavelength according to the Beer-Lambert Law. While it may
be used for general elemental analysis, this technique is common for analyzing
metals in environmental, clinical, and pharmaceutical samples. AA instruments are typically benchtop models. It is a mature technology and is available
from multiple instrument manufacturers with various atomizers, light sources,
and detector configurations.