Saturday, March 14, 2020

Principle and Application of Partition Chromatography

What is Partition Chromatography?

Partition chromatography is a type of chromatography in which the analytes of a sample mixture distribute more likely in two liquids, due to differences in partition coefficients. In partition chromatography, both the mobile phase and the stationary phase are in the same phase and in which the analytes are separated. Therefore, the analytes are preferably distributed in any phase.


Partition Chromatography Principle:

The separation of analytics from a sample solution is done by the method of partitioning the analytes between two phases. Partition chromatography is a basic principle used in many different methods such as gas chromatography, paper chromatography, high-performance liquid chromatography, and thin-layer chromatography (TLC). Partition chromatography is usually understood as a means of solute partitioning using the separation of two liquid phases. The process of separating the sample mixture of compounds passes through a solid stationary phase in which the components travel with a mobile phase. The mobile phase travels from the stationary phase and separates the components according to the affinity towards the stationary phase.

Partition Chromatography Procedure:

  • For an easy understanding of partition chromatography, here is the procedure for conducting paper partition chromatography.
  • Select a suitable type of development: It is determined based on solvent, paper complexity, mixture, etc. Ascending paper chromatography is widely used as it is simple to do. It is also simpler to use and the chromatograms are rapidly obtained.
  • Choosing a proper filter paper (stationary phase): Filter paper is selected based on pores size and quality of the analyte.
  • Preparation of sample: Sample preparation involves dissolving the component in a suitable solvent used in the process of producing mobile phases.
  • Spot the sample on paper: Apply the sample mixture to the appropriate position on the paper using a capillary tube.
  • Development of chromatogram: Using the chromatographic jar, the development of the chromatogram is observed by immersing the paper into the solvent or mobile phase. The mobile phase runs over the test sample by capillary action.
  • Paper drying and the identification of compounds: Once the chromatograms are developed then the paper is dried by an air dryer. Paper with a different band of molecules can be examined in the UV cabinet and Rf values are determined.

Partition Chromatography Applications:

  • Paper chromatography has various applications. Some applications are mentioned below.
  • It is used as a qualitative analytical chemistry method to detect and separate color mixtures including pigments.
  • Partition chromatography is used to separate and identify proteins, nucleic acids, sugars, glycosides, lipids, alkaloids, and other biomolecules.
  • Partition chromatography is used for the isolation and identification of amino acids.
  • It is used to separate polar and non-polar molecules.
  • It can be used to test the purity of pharmaceuticals and to monitor the chemical synthesis reaction.
  • It can be used in forensic research for investigations and criminal trials.
  • It is also used for DNA/RNA sequencing.
  • It is used to detect pollutants in beverages and food products.

Types of Partition Chromatography:

Their are two types of partition chromatography are available, liquid-liquid chromatography and gas-liquid chromatography.
Liquid-liquid Chromatography: In this type of partition chromatography a sheet of absorbent paper is used instead of an adsorption column. The analytes are separated based on their differential migratory velocity. When chromatograms are separated, they are stained to make them visible.

Gas-liquid Chromatography: It is a type of partition chromatography in which the sample mixture is separated by an inert gas with a tube. The tube is packed with finely divided inert solids which are coated with nonvolatile oil. The migration of each analyte occurs at a rate that is determined by both its oil solubility and vapor pressure.

The Advantages of Partition Chromatography are as Follows.

  • The advantages of partition chromatography include a simple to operate and an inexpensive separation technique.
  • It has high efficiency.
  • The partition chromatography method can separate organic as well as inorganic compounds.
  • This gives accurate results compared to other chromatography techniques.
  • It separates compounds in a short period.

The Disadvantages of Partition Chromatography are as Follows.

  • The data cannot be stored long, which is the major disadvantage of partition chromatography
  • Sometimes high amounts of solvents are required for separation.
  • Automation made more complicated and expensive.

Difference between partition and adsorption chromatography:

The major difference between partition and adsorption chromatography is that the partition chromatography separates the analytes by partition, while adsorption chromatography separates analytes by adsorption.

Commonly asked questions on chromatography are as follows.

What is partition chromatography in chemistry?
It is a separation technique whereby the component mixture is more likely to distribute into two liquid phases due to variation in the partition coefficient in the stationary phase during mobile phase flow.

What is the principle of partition chromatography?
The principle of partition chromatography, which consists of two phases, a mobile phase and another are stationary phase, and the sample is separated amongst the two phases based on affinity at each phage.

What are the two main types of chromatography?
Liquid chromatography (LC) and gas chromatography (GC) are the two main types of chromatography.

What is the purpose of column chromatography?
The main objective of column chromatography is to separate the components with different molecular structures.

Why must the TLC chamber be covered?
During the development of the chromatogram, it is significant to have covered the chamber, since that the solvent vapor in the chamber will saturate the air, the mobile phase does not evaporate and the chromatogram develops correctly. This is the main reason to cover the chromatography chamber.


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