Re: Will the results be the same if using two different types of chromatograpy?

Hello Kari,

Chromatography is a powerful technique for the separation of mixtures into
their individual components.  There are a range of different types of
chromatography, including paper and thin layer chromatography (TLC), gas
liquid and gas solid chromatography (GLC and GSC)and high performance 
liquid Chromatography.

In short, the answer to your question is yes, the same mathematical 
procedures do apply to the different types of chromatography.  The most 
important fundamental parameters associated with all types of 
chromatography are: 

-Effeciency, or the narrowness of peaks.  The more narrow the peaks the 
more efficient is the speparation process.  A measure of the efficiency is 
known as the Number of theoretical plates, N.

-Resolution is a measure of how well two peaks eluting close together are 
separated.

The equations for working out these parameters are the same regardless of 
the type of chromatography you use.

You do have to be careful when thinking about the different types of 
chromatography however. For example, with gas chromatography, the sample 
must be easily vapourised.  As most salts are very difficult to get into 
the vapour or gas phase (you usually need a very hot flame) they would not 
be analysable by GC.  If you need to Separate a mixture of salts, which 
are charged (sodium chloride for example exists as a positivley charged 
sodium ion and a negatively charged chlorine ion)you would use a technique 
known as ion exchange chromatography.

The principle of all types of chromatography is the interaction of the
analyte or solute with a stationary phase and a mobile phase.  As the name 
implies,when a molecule is dissolved or adsorbed onto the 
stationary phase,it is stationary.  Molecules which have a large affinity 
for the stationary phase are eluted(come of the column) later.  Molecules 
which have a lesser affinity for the stationary phase are eluted sooner.

Hope this helps,

Steve.