What is chromatography ? Chromatography (from Greek χρώμα:chroma, color and γραφειν:graphein to write) is the collective term for a set of laboratory techniques for the separation of mixtures. It involves passing a mixture dissolved in a "mobile phase" through a stationary phase, which separates the analyte to be measured from other molecules in the mixture based on differential partitioning between the mobile and stationary phases. Subtle differences in a compound's partition coefficient result in differential retention on the stationary phase and thus changing the separation.

Chromatography may be preparative or analytical. The purpose of preparative chromatography is to separate the components of a mixture for further use (and is thus a form of purification). Analytical chromatography is done normally with smaller amounts of material and is for measuring the relative proportions of analytes in a mixture. The two are not mutually exclusive.
No . it is not . As chromatography is usually used for small amounts .
Other types of chromatography are , #

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o 3.2.1 Paper chromatography
o 3.2.2 Thin layer chromatography

# 4 Displacement chromatography
# 5 Techniques by physical state of mobile phase

* 5.1 Gas chromatography
* 5.2 Liquid chromatography

# 6 Affinity chromatography

* 6.1 Supercritical fluid chromatography

# 7 Techniques by separation mechanism

* 7.1 Ion exchange chromatography
* 7.2 Size exclusion chromatography

# 8 Special techniques

* 8.1 Reversed-phase chromatography
* 8.2 Two-dimensional chromatography
* 8.3 Simulated moving-bed chromatography
* 8.4 Pyrolysis gas chromatography
* 8.5 Fast protein liquid chromatography
* 8.6 Countercurrent chromatography
* 8.7 Chiral chromatography

These are some disadvantages of using paper chromatography:

1. It can be used as a preparative technique because we can't aplly a large sample quantity;

2. It can't be used in quantitative analysis;

3. and doesn't allow the separation of complex mixtures.

the advantage of using paper chromatography :

1. It's less expensive to perform, and you can do "two way" chromatography by running a chromatograph in one solvent, letting the paper dry, turning it 90 degrees and running a second chromatograph in a different solvent.

Thin layer chromatography is faster and more accurate, so it's more popular now.



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