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

The use of the programmed-temp. vaporizing (PTV) injector as a versatile interface for large-vol. injection in capillary GC is proposed. By using a special on-column insert, in addn. to large-vol. solvent-vent injection, also large-vol. 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 vapor exit is installed between the on-column insert and the anal. column. The performance of this set-up for large-vol. injection was evaluated and is similar to that of large-vol. injection using a conventional on-column injector. The proposed instrument hence allows PTV and on-column large-vol. sampling to be performed using only one injector. This greatly reduces instrument costs for large-vol. sampling equipment. Guidelines are given for method development for large-vol. sampling. [on SciFinder (R)