Identification of Compounds (Qualitative Analysis):

It should be known that along with a particular column if all the variables like as temperature and flow rate are carefully controlled, a retention time or retention volume of a solute is a property of in which solute, just as its boiling point or refractive index is a property. This amounts to the fact in which retention behaviour could be used to identify a compound. If one wishes to identify the unknown compounds in a mixture, the standards are run under identical conditions and through matching the chromatograms of unknowns and standards, a former are identified. At this point it might be significant to point out that such kind of identification is not the strong point of gas chromatograph. There are instruments such as mass spectrometer that can give more information about the unknown. Primarily GC is a good separation technique. If it is hyphenated along with instruments such as mass spectrometer or infrared spectrometer, the system provides an ideal set up for identification of the unknowns present in a combination. The mass and the ir spectra give valuable information about the column eluants. There are several other approaches that are used in conjunction along with GC to identify the separated components. A discussion on these is not being taken up here.