Header Ads

Latest Publications

Different types and term of chromatographic technicques

Common terms in various chromatographic methods
Gas chromatography:

Gas chromatography is a type of column chromatography method, in which the mobile phase is gas and the stationary phase may be an immobilized liquid or a solid crowded in a closed tube. GC is worn to split thermally stable volatile gears of a mixture.
Gas–Liquid Chromatography:
Gas chromatography specifically gas–liquid chromatography requires a vaporization of  a sample and  implant it onto  the top of  a column. Under restricted temperature ascent the mock-up is elated through the column by the course of a non-reactive gaseous mobile phase. Volatile gaseous sample  are again  separated which are  made on several properties  such as boiling point  size of molecules and polarity.

Applimentation of chromatographic theory to gas chromatography:
However, details of the chromatographic theory of separation as it applies specifically to GC liquid Chromatography.

Types of liquid chromatography in different fields:
There are many types of liquid chromatographic  techniques which are  applicable  in planar chromatography (paper chromatography, thin layer chromatography (TLC) ) food analysis  and column liquid chromatography, all of these involve a liquid mobile phase and  a solid or a liquid stationary phase.
Physical form of stationay phase:
 The  stationary phase which is present in physical forrm is totally different in every situation . Solute separation is based on the physiochemical relation  between two phases
Paper Chromatography :
Introduction of Paper Chromatography :
Paper chromatography was discovered in 1944.  Paper chromatography includes both  stationary phase and mobile phase in liquid form .
Mechanism of paper chromatography:
Development of chromatogram:
Paper usually acts as a supporting material  for  liquid stationary phase. The slurry is useful  in the form of little spot or point and about one half of the  inch  more from the rim of a narrow piece of square of  a filter paper generally cellulose made paper which is allowed to dry. Then dried slit is poised in a blocked jug with saturated atmosphere, containing developing solvent in the form of mobile phase  and then development of  paper chromatogram is completed.

The end which is close to the sample is kept  in touch  with the solvent,  and this moves  up or down the paper with help of  capillary action depending on whether ascending or descending development is used  separation  of  components of sample in the process. When the front of the solvent travels  along the distance end to end of the paper then piece of paper  is removed from the developed  compartment and the separated areas are visualized with the help of  an appropriate method.
Stationary Phase In Partition  Paper Chromatography:
The stationary phase in paper partition chromatography is usually water. Moreover the support which is saturated by a non polar solvent which is organic   and  is developed by the help of water and may be other polar solvents Reversed-Phase Paper Chromatography.
Handling of complex mixtures:
In  situation of handling of  mixtures which are in complex form  then two-dimensional technique is applied. The sample is patterned at one corner of the  paper which is  in square shape and one solvent is used for the development of  the paper kept in one direction.  After this the development  chromatogram is kept for drying under temperature of 90o and developemental process is repeated again after the use of another polar solvent.

Methods for the improvement of resolution:
Another way for the  improvement of  resolution which is the exploit of ion-exchange method  in which  impregnated paper with ion-exchange resin or derivatized cellulose paper by the applimentation of any acid or any base.

No comments