Chromatography Forum

Hi,

Sorry to ask again, but i am still dealing with this machine (HP 5971/GC 5890). Now, i can obtain more or less a proper signal (water and air < 5% of peak 69), but as soon as i increase the temperature of the oven I observe an increase in the air and water levels. If I decrease the temperature the levels are OK again, after a while. Could i have a pore in the column which is widening with the increase of temperature?
Any help is welcome

Thanks

Jose

Tighten the fittings while the oven is hotter, there can be expansion/contraction issues. Focus on the MSD interface, the 1/2 nut holding the gold seal and its washer in place, the weldment retainer nut, and septum nut. The issue is in the GC, not the MSD, you've already isolated that issue.

I will try replacing ferrules and setting another column... we'll see what can i obtain.

Many thanks!

Maybe gas trap or gas cylinder is contaminate.When oven temp increase, water trap on column head is liberate.Bypass gas trap...what is the result???
Good luck!