What is causing these baseline deviations on the TIC?

Hi

First check column n inlet of GC..

If still problem continue then MS preventive maintenance require...

Thank you for the reply.  What am I checking for with the column and inlet?  I'm guessing there is some kind of contamination but I don't know what to do to get rid of it.

Either change column or condition the column.

Inlet, you can change liner, septa and gold seal..

Either change column or condition the column.

Inlet, you can change liner, septa and gold seal..

Ok, I will try conditioning first.  We use a gas sampling valve so I'm not sure how that relates to the inlet.  

Gas sampling valve is connected with inlet of GC or directly from valve sample is going in column.

Are you using capillary column or packed column?

Injection split /splitless or direct?

Caplilary, split/splitless injector.  Should I condition the column with the end removed from the MS? Or is it ok to leave everything connected while conditioning?  There is two columns, the other one goes to a TCD/FID.

Yes..should be remove from ms and ms should be capped with blank nut otherwise all contamination of column will go to MS.

Injector( split/splitless) septa, liner n gold seal should be checked/replaced to avoid  contamination

Vent the MS before removing column end and conditioning?  I don't have any blank nuts unfortunately.

Yes..u have to vent it..