We have checked for leakes, controlled the pressure and flow, with no remarks. The beseline is fine and the seperation so far also good, but the retentiontimes keep dropping about a minute, every couple of days.
When you say dropping do you mean what was coming out at 3 minutes is now coming out at 2 minutes?
What is your method parameters? Split ratio, inlet temps, oven temps and ramps, etc. Also what is your maximum tmeperature tolerance on your column?
Have the peak shapes changed at all or is it just the retention time?
Is it a difference of 1 minute every couple of days with every compound or just a few?
.Gcchaplian has some good questions. Instrument type and configuration, detector etc is all info that will help the community help you.
I will mark this post as assumed answered due to age. If this isn't the case, feel free to post again. If any response was particularly helpful, feel free to mark as correct answer .
Retrieving data ...