Sampling and Introduction of Sample Into Gc Unit:

For analytical results to have any validity or meaning, adequate sampling procedures should be adopted. Sampling is the procedure of extracting from large quantity of material a small portion that is truly the representative of the composition of a whole material under scrutiny. Proper sampling within GC supposes a particular significance since here we deal along with the analysis of gaseous substances or components that are volatile.

The sampling process involves several steps:

1.         Removal of an aliquot from a bulk quantity which is representative of that bulk.

2.         If necessary, alteration of the physical state of the sample (e.g. that of gas) so that it can be manipulated.

3.         Transportation to the laboratory for analysis.

4.         Storage prior to analysis.

5.         Introduction of the sample into the GC unit for analysis.