Sampling syringe:

Sample introduction for liquids on packed columns is often accomplished with a microsyringe through a self-sealing silicon septum as shown in Figure.

Figure:  Simplified injection port for on-column injection

In this figure, the column is lined up colinearly with the syringe needle providing for two possible injection modes: on-column or flash vaporization.

For on-column operation, the column is positioned as shown in Figure with the column packing beginning at a position just reached by the needle. While the syringe is pushed as far as it will go within the port, its contact will be delivered into the first part of the column packing, ideally on a small glass wool plug used to hold the packing in the column.

In the second configuration, the column is placed so that its front end and its packing barely extend into the injection port and cannot be reached by the syringe needle. Efficient sampling for this configuration needs in which the solutes evaporate quickly (flash vaporization) while injected into the port.