Loop sampling with two column sequence reversal

Two position valve application – 10 port valve
(Non-Java)

This is ideal for fixed gas-from-CO₂ analysis where no "high boilers" are present. Column 1 is packed with a porous polymer and Column 2 with molecular sieve. The sample loop is loaded in Position A. When the valve is switched, the loop contents are sent onto Column 1. As the inorganic gases and methane leave Column 1 and enter Column 2, the valve is returned to Position A, reversing the column sequence. CO₂ now leaves Column 1, becoming the first peak. The inorganics and methane are separated by the mole sieve and pass through the porous polymer column to the detector.

Further reference

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