In: Chemistry
With the aid of a clearly labelled schematic diagram, illustrate the main layout of a flame atomic absorption spectrometer with continuum source background correction. Describe briefly the purpose of each component.
Your diagram should include reference to the following components:
The hollow cathode lamp The flame and burner
The deuterium lamp The monochromator
The modulator or chopper The detector
Flame atomic absorption spectrometry is a quantitative analytical method based on
measuring the light absorption of free, ground state atoms.
The relationship between the decrease of light intensity at the wavelenght of the examined metal and the concentration of free atoms in a unit of volume is obtained by Lambert-Beer law
A= log(Io/I) = a.c.l
where A=absorbance, Io= initial light intensity before absorption,I = Light intensity after absorption
a = absorption coefficient (constant depending on material properties)
c = number of free ground state atoms in the atomizing unit (flame)
l = lenght of way passing the light in the atomizing unit