• The injection port serves the purpose of providing a place for
sample introduction, its vaporization, and possibly some dilution
and splitting.
• The injection port contains a soft septum that provides a gas-tight
seal but can be penetrated by a syringe needle for sample
introduction.
• The sample must be vaporized in the injection port in order to pass
through the column for separation.
• The injection port may serve the additional function of splitting the
injection so that only a portion of the analyte goes on the column.
Capillary columns have limited capacity for the injection volume.
• There are several different designs of injection port available to suit
the variety of samples. These include the standard heated port,
temperature-programmed, and on-column injectors