The sample enrichment functionality of the UNIS 2100 PTV by means of sample enrichment in the liner is described below (e.g. LVI through multiple injections).

The sample injection is made into the moderate heated or cooled inlet. The ring restrictions in the liner lead to the Bernoulli Effect as precondition for large volume injections. Due to the low pressure right below a ring restriction the solvent evaporates and the sample remains. The more ring restrictions the sample traverses the more solvent evaporates - combining this process with multiple injections leads to successful sample enrichment in the inlet. The evaporated solvent is flushed out with the carrier gas through the vent outlet. When the vent outlet is closed and the inlet ballistically heated up, the carrier gas flushes the enriched sample onto the column. Sample concentration reached in this way gives you much sharper peaks plus huge time savings.

Please have a look at the UNIS 2100 animation to view a simple illustration of the operating principle of the JAS GC inlet system.