Chromatography

Chromatography is made up of two words chroma which means color and graphein which means to write. Let's explore this wonderful concept used widely to separate different components in a mixture.

What is chromatography?
Chromatography is a process which helps to separate the components of a homogeneous mixture. The process thus helps in the quantification and analysis of the mixture and its components.

Scientists use this method to find out the different components that make up the mixture. This is a physical method which consists of the components distributed in two phases: mobile phase and the stationary phase.

The stationary phase is the mixture which is to be separated into its components and the mobile phase is the liquid which can be a solvent. The components in the mixture separate on the basis of the solubility and their differential affinity to the mobile and the stationary phase.

On the basis of the type of the stationary phase, the mobile phase and the separation mechanism, chromatography can be classified into different types.

Classification of chromatography

1. On the basis of the stationary phase

• Planar chromatography: the stationary phase is on a plane support.
• Column chromatography: the stationary phase is in the form of a column.

2. On the basis of the mobile phase

• Gas chromatography: when the mobile phase used is the gas.
• Liquid chromatography: when the mobile phase used is a liquid.

3. On the basis of the separation mechanism

Classification on the basis of the separation mechanism depends on how the components are separated.
Ion exchange chromatography, affinity chromatography, partition chromatography, exclusion chromatography and adsorption chromatography are some types of chromatography based on the separation mechanism.

What are the uses of chromatography technique?
It is used widely in the researches carried out in the field of biotechnology, pharmaceutical industry and manufacturing plants. The environmentalists use it to find out the level of pollutants in the water samples.

The forensic labs use it to detect, quantify, separate and identify the samples which they obtain at the site of crime. The technique is used in the manufacturing plants to purify the samples and the products.

What are the benefits of chromatography technique?
The primary benefit is that the complex mixtures can be separated into their components. Very small amount is required for this purpose. The other benefit is its simplicity. The method is simple and takes less time. The method does not require costly setups and no major expertise is needed to perform the task. It can separate in fact any substance soluble or volatile in nature if the right mix of solvent, absorbent material, fluid carrying the components and operating conditions are used.