Introduction 
    • Many determinations made in the clinical laboratory are based on 
    measurements of radiant energy 
     • emitted, transmitted, absorbed, scattered, or reflected under controlled 
      conditions. 
    Introduction
    • Flame emission spectrophotometry
      • based on the characteristic emission of light by atoms of many metallic elements 
       when given sufficient energy, such as that supplied by a hot flame.
    • Photometry
      •  is defined as the measurement of light
    • Spectrophotometry
      •  is defined as the measurement of the intensity of light at selected wavelengths.
      • For example,
        • Lithium  produces a red, sodium a yellow, potassium a violet, and magnesium a blue color 
         in a flame.
   • the light intensity of the characteristic wavelength produced by each 
    of the atoms is directly proportional to the number of atoms that are 
    emitting energy, which in turn is directly proportional to the 
    concentration of the substance of interest in the sample.
    Instrumentation of flame emission spectroscopy 
    (FES)
    • 1)Vaporization:
     •  The solvent is vaporized leaving particles of solid salt.
    • 2) Atomization:
     •  The salt is converted into free neutral gaseous atoms or radicals
    • 3) Excitation:
     •  Some of these atoms are excited by the thermal energy of the flame to 
      higher