Different between HPLC and GC
HPLC: high
performance Liquid chromatography
HPLC is one of the chromatography
techniques where the stationary phase is liquid or solid and the mobile phase
is liquid.
GC: Gas
chromatography
GC is also one of the
chromatography technique where the stationary phase is solid or liquid while the mobile phase is gas.
The main difference between the HPLC and GC is the mobile phase.
Example of mobile phase:
In HPLC chromatography liquid
solvents are used as the mobile phase they may be the polar or the non polar
solvent.
Example of polar solvent: Acetonitrile, Water , Dimethyl Sulfoxide
Example of non polar solvent: Hexane , Chloroform
In gas chromatography the mobile phase used is the inert gases following are the example of the mobile phase Helium, Nitrogen, Hydrogen, argon, and Air.
Compound to be analyzed
HPLC mainly used to analyze the less volatile compound. The sample should be in liquid form hence it should be soluble in the solvent. Gas chromatography only volatile compound is the analyze by the Gas chromatography. The chromatography sample shall be stable at high temperatures.
The temperature during the analysis
HPLC analysis is done at room temperature only. In GC analysis compound must be in vapor form to analyze. Gas chromatography requires a high temperature. For high temperature oven facility is available.
Column:
In HPLC column the liquid mobile
phase is used and in gas chromatography gas is the mobile phase the liquid mobile phase creates more pressure than the gaseous mobile phase. Hence the column
length of the gas chromatography is more than the HPLC column.
Generally, the length of the HPLC column
is 5 to 50 cm long. The column of the HPLC is shorter wide and thick. Packed
columns are used in HPLC.
The gas chromatography column is long and narrow. Generally, the length of the column is 10 to 30 meters long. Two types of the column are used packed column and the capillary column.
Cost:
HPLC is costly than the Gas chromatography. The solvent of the high performance chromatography is costly than the gas. The second reason is HPLC requires the pressurize system to pump the liquid mobile phase. It is quite complex and the High performance liquid chromatography system requires more maintenance than the gas chromatography.
Method of detection of Sample:
In the detection of the HPLC UVs,
RI, photodiode methods are used. While in gas chromatography FID (flame
ionization detector), TCD (thermal conducting detector) different methods are.
Generally, the method used in the detection of HPLC is nondestructive while the method
of GC is destructive.
Now day’s mass the spectrometer is attached with the both high performance liquid (HPLC) and gas
chromatography (GC) to achieve a better result.
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