MS5A is this a packed or capillary column?
You should see something elute. Even if the pores were completely blocked gases would elute around the particles.
I suspect a crack in your capillary column or a leaking connection if it is a packed column.
That or the column is completely blocked. Did you flow check?
mole sieve is damaged by temperature if water is present in the pores. A chemical reaction takes place. If dry you can heat the packing to 400C. But again, if oxygen is present, chemistry can take place.
Usually condition the column at the highest flow rate possible at a temperature below 150C and then two degrees per hour to 200C. Then slow decrease the column flow to normal rates. Heating higher than this will gain you about 10% more separation but increases the likelihood of chemical damage enormously. Why bother? Damage is determined by tailing of the gas peaks. A good column has little or no tailing. A damaged column can have a lot.
best wishes,
Rod
