36.3 Principle........................................
“The test solution is passed asfine spray into theflame. Theflame evaporates the
sample and dissociates the salts to give neutral ions. The heat energy of theflame
excites some of these atoms which cause electrons to move to a higher energy level.
The electrons are unstable in the excited state and hence return to lower energy level.
In this process, the electrons will emit a light of afixed wavelength of electromag-
netic spectrum. The amount of light emitted is directly proportional to the number of
atoms undergoing in excited state. The number of electrons in excited state in turn is
directly related to the concentration of the substance in the sample. Sodium emits
yellow light of 589 nm, whereas potassium emits violet light of wavelength maxi-
mum 404.4 nm and 765.9 nm (Fig.36.1).
36.4 Reagents........................................
1.Stock sodium 1000 mmol/L:Dissolve 5.85 g of NaCl infinal volume of 100 ml
distilled water.
2.Stock potassium 100 mmol/L:Dissolve 746 mg of dried KCl infinal volume of
100 ml distilled water.
Fig. 36.1 Schematic representation offlame photometer
148 36 To Estimate Sodium and Potassium in Serum by Using Flame Photometer