Absorption of radiant energy by free atoms in ground state Light source used to emit characteristic energy known as Hollow cathode Lamp The absorption is proportional to the concentration of free atoms follows the Lambert-Beer law
Absorbance = log10 Io/It = K.C.L.
In practical the Lambert-Beer's law can be reduced to Absorbance = log10 Io/It C
Determination of trace element in all types of environmental, biological and food samples. Non-volatile metals viz., Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Zn are analysed in flame system and Volatile metals viz., As, Se, etc are analysed using hydride generation accessory (FIAS) , graphite furnace (GAAS)