1.
Explain the technique used in Flame-AAS that will prevent loss of sensitivity of analyte
through ionization.
Solution
Atomic absorption spectroscopy is an excellent technique used to determine the elements
quantitatively. There are three types available in AAS (i) Flame (ii) Graphite furnace (iii) vapour
generation. In order to prevent the loss of sensitivity of anlayte , the burner is adjusted in such a
way (either vertical, horizontal) that the free atoms fall in the light path of hollow cathode lamp
when exposed to flame. The sensitivity depends compelety on the hollow cathode lamp. The
longet the path length , the greater the sensitivity. The problem can also be overcome by adding
excess of ionizable atoms such a Cs, K which suppresses ionization. Other than this grahite
furnace will provide good sensitivity