1. What is Chromatography

Chromatography – What is it?

In 1903, Russian botanist Mikhail Tswett used a calcium carbonate column for the separation of plant pigment. He was able to separate larger volumes of plant pigments based on color, hence the name chromatography.

chroma (χρῶμα) = colour

graphein (γράφειν) = to write

Modern Chromatography is a separation technique based on the partitioning of molecules in the stationary phase – in the case of Mikail Tswett it was the calcium carbonate.

Partitioning = dividing into parts

Stationary phase = solid (liquid) phase on which molecules partition – are selectively adsorbed to separate

Mobile phase = liquid or gas that moves molecules through a stationary phase

 

Uses of Chromatography

There are two principal uses of chromatography:

a) Preparative – used to separate and purify larger volumes of mixtures for further processing

b) Analytical – analytical separation technique to identify and quantify compounds

 

Basic Types of Chromatography

There are many types of chromatography as per the image below. The two most commonly used types are based on what type of mobile phase is used to aide the separation.  

a) Liquid – mobile phase is liquid

b) Gas – mobile phase is gas