Skip to main content

Gas Liquid Chormatography

 Gas-liquid chromatography (GLC) 

This is the method of choice for the

separation of volatile substances or the

volatile derivatives of certain nonvolatile substances. In GLC, the

stationary phase is an inert solid

material (diatomaceous earth or

powdered firebrick), impregnated with

a non-volatile liquid (silicon or

polyethylene glycol).


Gas chromatography is a method of choice used to separate a mixture of compounds that are volatile or can be made volatile. The components in

the sample are purified on the basis of partition between a gaseous mobile phase and a liquid stationary phase.

Commonly used gas is inert (nitrogen, helium or argon) and simply carries the molecules through the column, it is called a carrier gas. The column packed of a nonvolatile liquid coated on an inert solid support (Diatomaceous earth or powdered firebrick). The mixture of substances is injected into the column along with the mobile phase,which is an inert gas.

The partition of the volatile mixture is based on the separation of the components between

the mobile phase (gas) and stationary

phase (liquid), that is why it is known as gas liquid chromatography.

Separated compounds can be identified by a detector. 

Basically this detector works on the principles of ionization or thermal conductivity.

Gas-liquid chromatography is reliable, sensitive and rapid. Sometimes it is used

for quantitative estimation of

biological materials such as drugs,

lipids and vitamins.

Comments

Popular posts from this blog

What is Chromatography and its types

The word ‘chromatography’ is derived from Greek word ‘Chromo’ meaning colour and ‘graphy’ meaning to measure; initially it was used to separate coloured compounds from the mixture.   In another words It is an analytical technique used for the separation of closely related compounds from a mixture. These compounds are proteins, peptides, lipids ,amino acids, carbohydrates, vitamins and drugs. Chromatography was discovered by Russian Botanist Tswest in 1903. He used it for separation of plant pigments for the first time. The early methods used for the separation and purification of compounds from mixtures were labourious, and s  s low.  With passage of time and advancement in the separation techniques over years, the chromatographic technique has become to be known as used for the separation of different compounds from mixture and for their identification. Principle of Chromatography Chromatography is usually  consists of two phases first a mobile phase and secondary i...

What are Enzymes and it's types.

 Enzymes are proteins produced by the living cells, which are capable of catalyzing  a chemical reaction in a living organism to yield specific product, without getting used up. • They never initiate any reaction rather only accelerates the pre-cxisting reaction. • Enzymes are biological catalysts. Catalyst These are the agents, which in minute amounts increase the velocity of a reaction without appearing in the final product of the reaction. Substrate The compound on which an enzyme acts is called its substrate. Nomenclature Names of enzymes usually end in "ase" which is preceded by the name of its substrate.

High Performance Liquid Chromatography

  High performance liquid chromatography (HPLC)    In general, the chromatographic techniques are time taking and slow. Therefore, the separation of interest can be improved by using high pressure in the range of 5,000-10,000 psi(pounds per square inch), so this technique is commonly known as high pressure liquid chromatography.  This tecnique requires the use of non-compressible resin materials and strong metal columns. At last the eluants of the column are detected by using methods such as fluorescence and UV absorption. High liquid chromatography is commonly used for the detection and estimation of vitamins (e.g. vitamin A, calcitriol, etc.), drugs (e.g. phenytoin, phenobarbitones, LSD, AZT, etc.) hormones (e.g. epinephrine, norepinephrine, ACTH, etc.), and metabolites (e.g. metanephrines) in clinical laboratories