Question

Please answer the questions related to gas chromatography:

(1) Principle of distribution chromatography.

(2) The purpose of programmed temperature.

(3) Split injection of sample for the purpose.

Answer 1

Ans(1). Separation of components on the basis of their distribution coefficient is the the principle of distribution chromatography

Distribution coefficient (K_D​​​​​​) = equilibrium constant for distribution of an analyte

K_D=[C_s​​​​​​] /[C_M]

C_s= conc. Of analyte in the stationary phase

C_M= conc. Of analyte in the mobile phase

Ans(2)= the purpose of temperature programming is for completion of analysis faster

Basically lower boiling point moves faster and molecules having high boiling point moves slower so here temperature programing is used to increase the rate of analysis of molecules having high boiling point.

Ans (3)=split injection of sample for the purpose to avoid overloaded peaks

It is used when analyte concentration is high, only some amount of vaporized sample is transferred into the head of the column and the remaining removed from the split vent line.