Chromatography Forum

Recently I have trouble on the GC-MS sensitivity, so I just cleaned the ion source in MS, and cleaned inlet part, however, after I increase the sensitivity I have new trouble in peak shape and baseline, you can see high baseline and baseline drift and also peak tailing very badly.
Thanks for your time.

Peak shape can be the result of a problem in the inlet or gc column - the particular bad peak shapes are diagnostic for the problems encountered. Check the websites of the suppliers of parts and supplies for GC for a troubleshooting guide. Years ago I had a small booklet from Supelco that had a fairly throuough description. It may have been long enough ago that it covered only packed GC columns -- because that's all there were "back in the day."

Baseline issues, again, have many causes. They result from either material slowly leaving the column (stationary phase bleeding off, residue from previous injections, etc.), detector issues, or electronics problems.

A bit more detail is requried to help sort this one out. I would suggest starting with a troubleshooting guide. You may recognize a problem and fix it faster than you can type a more detailed description. I will look to see either your success or more details.

update:

I tried cleaned the TDU inlet yesterday, take them apart, cleaned and put them together, change new Cis liner, rerun it , the question is: without sample, just run empty tube(blank), the baseline is not noisy or high, so I double the problem of column bleeding, however, when I tried to run the sample, problem comes again. Compare to precious run it exactly looks same, I will change a wax column instead of this HP-5 column to check it, make sure what's going on.

If I successfully fix the problem I will update more.

Thanks

update:

Finally I solve the problem, it from the installation of column, one session is not connect very good, so after I reinstall the column, chromatograph finally looks beautiful. Thanks guys, and have a good day.

Thanks for the feedback.

Peter