Chromatography Forum

Hi everybody

I have been tasked to get in shape a Shimadzu GCMS 5050. This instrument hasn't been used for a couple of years. I cleaned the ion source and the system pumps down fine. However, while trying to autotune I keep getting a “mass calibration error” message. The manual tune is possible (using PFTBA, see picture) but I simply can’t get rid of such an error, considering that my manual tune is good.

https://ibb.co/qMBz2bk

Any thoughts? Thanks a lot for your help.

You have >2 millon counts on the 69 peak at 0.6 half height peak width. But the target is 0.5. Not sure if the >4000EV is the max on your EM. But it appears that its unable to meet peak width targets. And, it might be boosting the EM to the limit trying to get headroom to narrow the peaks. On an Agilent 5973 you would be looking for maybe 600,000 counts on mass 69. So maybe the target for counts on 69 have been set too high.