ABSTRACT
The analytes are detected at their exit from the column. Each molecule is characterized by a retention time that corresponds to the time that passed between the injection of the analyte and its arrival at the detector. Concerning volatility, the separation principle is simple: the speed at which a compound migrates in the column relates to its boiling point. The boiling point is a thermodynamic measure that depends mainly on two factors: the molecular weight and polarity. A compound is as volatile as its molecular weight and polarity are low. The interaction between analytes and the stationary phase are more complex; one must chose the type of chemical film to use according to the nature of the molecules that need to be separated.
