Chromatography Types | gas chromatography, liquid chromatography, HPLC, paper chromatography

Summary

This video introduces the concept of chromatography and its various types, which are classified based on the phases of the solvent (solid, liquid, or gas). The video explains the key components of chromatography, including the stationary and mobile phases, and how different molecules interact with these phases to facilitate separation. It covers techniques like gas chromatography, liquid chromatography, ion exchange, exclusion chromatography, and more. The focus is on understanding how chromatography is used to separate molecules based on properties like charge and size, with examples such as HPLC, TLC, and supercritical fluid chromatography.

Takeaways

• 🔬 Chromatography is a technique used for the separation of molecules based on their properties like charge and size.
• 🧪 The process involves two phases: a stationary phase that is fixed and a mobile phase where molecules move.
• 🌐 Chromatography types are categorized based on the phase of the solvent used, which can be solid, liquid, or gas.
• 🌫 Gas chromatography separates gaseous molecules, with two subtypes: gas-liquid and gas-solid chromatography.
• 💧 Liquid chromatography involves the separation of molecules in a liquid phase, such as in high-pressure liquid chromatography (HPLC).
• 🌿 Examples of liquid chromatography include thin-layer chromatography (TLC) and paper chromatography, which use an organic solvent as the mobile phase.
• 🔍 Ion exchange chromatography separates charged or polar molecules by exchanging them on a solid stationary phase.
• 🔬 Size exclusion chromatography separates molecules like proteins based on their size and hydrodynamic volume.
• 🌱 Organic solvent-related chromatography, such as partition chromatography, uses dried liquid on a solid support and an organic solvent as the mobile phase.
• 🔗 The video script provides an overview and promises more detailed explanations of individual chromatography types in future videos.
• 📚 Viewers are encouraged to watch additional videos for a better understanding, with links provided in the video description.

Q & A

What is chromatography and what is its main purpose?

Chromatography is a technique used for the separation of molecules based on their properties such as charge, size, etc. Its main purpose is to separate different molecules from a mixture.

What are the two main phases involved in chromatography?

The two main phases in chromatography are the stationary phase, which is fixed and stagnant, and the mobile phase, where molecules move in either direction depending on the process.

How does the phase of the solvent determine the type of chromatography?

The type of chromatography is determined by the phase of the solvent used, which can be solid, liquid, or gas, and also by the phase of both the separation stage and the mobile phase.

What are the three major phases based on which chromatography can be divided?

Chromatography can be divided into three major phases: gas chromatography, liquid chromatography, and supercritical fluid chromatography, based on the state of the molecules being separated.

What is the difference between gas-liquid chromatography and gas-solid chromatography?

In gas-liquid chromatography, the mobile phase consists of gaseous molecules and the stationary phase is liquid, whereas in gas-solid chromatography, the mobile phase is gas and the stationary phase is solid.

What is HPLC and how does it differ from other liquid chromatography techniques?

HPLC stands for High Pressure Liquid Chromatography. It is a technique where the molecules are present in an aqueous solution, and it differs from other liquid chromatography techniques by the use of high pressure to facilitate the separation process.

What is the role of the stationary phase in ion exchange chromatography?

In ion exchange chromatography, the stationary phase is solid and is used to separate charged or polar molecules by exchanging them.

How does size exclusion chromatography differ from ion exchange chromatography?

Size exclusion chromatography separates molecules based on their size and hydrodynamic volume, whereas ion exchange chromatography separates molecules based on their charge.

What is the difference between partition chromatography and liquid-liquid absorption chromatography?

In partition chromatography, the separation is based on the partitioning of molecules between a stationary phase and a mobile phase, while in liquid-liquid absorption chromatography, the separation is based on the absorption of molecules onto a solid stationary phase from a liquid mobile phase.

What is the significance of using dried liquid in partition chromatography and thin layer chromatography?

Using dried liquid in partition chromatography and thin layer chromatography allows for the separation of different fractions of molecules present in the dried liquid by applying an organic solvent.

Why are supercritical fluids mentioned in the script, and how do they differ from other phases in chromatography?

Supercritical fluids are mentioned because they represent a unique phase that cannot be easily classified as liquid or gas. They carry a mixture of different types of molecules, and their separation requires a different approach than that used for gas or liquid chromatography.