Backflush of precolumn to vent

Two position valve application – 6 port valve
(Non-Java)

This plumbing scheme allows slower eluting components (end cut) which are not of interest to be backflushed to vent. Often a shorter version of the analytical column is used as the precolumn.

Once all components of interest have entered the main column (at port 2), the valve is switched, backflushing the precolumn to vent and reducing analysis time. An auxiliary source of carrier or mobile phase is required for this application.

Further reference

More applications with two position valves
Valco injectors and valves
Cheminert injectors and valves