Large-volume injection in capillary gas chromatography using a programmed-temperature vaporizing injector in the on-column or solvent-vent injection mode

Abstract

The use of the programmed-temperature vaporizing (PTV) injector as a versatile interface for large-volume injection in capillary GC is proposed. By using a special on-column insert, in addition to large-volume solvent-vent injection, also large-volume on-column injection can be performed with the PTV injector. For this, a set-up consisting of a retention gap, a retaining precolumn and an early solvent vapour exit is installed between the on-column insert and the analytical column. The performance of this set-up for large-volume injection was evaluated and found to be similar to that of large-volume injection using a conventional on-column injector. The proposed instrument hence allows PTV and on-column large-volume sampling to be performed using only one injector. This greatly reduces instrument costs for large-volume sampling equipment. Guidelines are given for method development for large-volume sampling.