What are the 4 Types of Chromatography?
Chromatography, also known as chromatography analysis, is a kind of separation and analysis method, which is widely used in analytical chemistry, organic chemistry and biochemistry. There are four main types of chromatography, which are Liquid Chromatography, Gas Chromatography, Thin-Layer Chromatography and Paper Chromatography respectively. We will mainly talk about Liquid Chromatography in the following parts.
What is Liquid Chromatography?
Liquid chromatography (LC) refers to a kind of separation technology, which takes liquid as the mobile phase.
This method is discovered and named by M.S.Tswett, who is a Russian botanist. During his research on plant pigments, he added plant pigment extract to the top of the glass column containing calcium carbonate particles, and then the column was washed with petroleum ether. As a result, different pigments were separated in the column and formed bands of different colors. Each band represented a different pigment. Since then, this type of methods is known as chromatography.
With the development of chromatography technology, it can not only used for separating colored substance, but can be widely used for separating colorless substance, especially organic compounds.
How does Liquid Chromatography Work?
The separation principle of liquid chromatography can be concluded as follows. When each component in the mobile phase passes through the stationary phase, the retention time in the stationary phase is different due to the interactions, such as adsorption, distribution, ion adsorption, exclusion, affinity, between components and the stationary phase have different magnitudes and strengths. Hence, they are capable of flowing out the stationary phase successively.
Precautions for Using Liquid Chromatography
- The mobile phase must use HPLC grade reagents, which should be degassed before use.
- Don’t run the device under overpressure. Stop it in case of overpressure and find out the causes. It can go on working after troubleshooting.
- Don’t use contaminated water to clean chromatography columns.
- Prevent incompatible solvents from coming into the pump together.
- Clean chromatography columns and detector’s colorimetric cells after completing the analysis.
What is Liquid Chromatography Used for?
The chromatography can used for separating and purifying materials, especially for materials hard to be separated by general methods, with less loss and high recovery rate. It is widely applied for separation, purification and preparation of plant active ingredients, natural products, organic synthetic products, protein biopolymers and other target active ingredients, satisfying both laboratory research and industrial production.