Headspace Pressure Issues

[ganna]

Hi there,

I'm trying to run GC-HS analysis and I'm having pressure issues on the HS side. The GC (Clarus 500) is fine but the HS (Turbo Matrix HS40) pressure is higher than the one set.

The set pressure is 15psi but it would not go lower than 19psi and this after waiting ages. I checked for leaks at the back of the instrument & gas connections but this seems to be fine. I was wondering whether someone had any idea what the problem could be & if possible how it could be fixed?

The GC carrier flow rate is 5 ml/min with a split flow of 10 ml/min & the carrier is Helium.

Thanks.
jane

[Rolandas Plausinaitis]

What pressure is on GC? I f you have there 30 psi, then you will not have 15 psi on headspace ever......

[Peter Apps]

Hi Jane

Depending on your column diameter, and whether you are setting pressures or flow rates on the GC and/or headspacer you will be forcing the pressure up by trying to squeeze too much gas down the column.

Peter