AnsweredAssumed Answered

No change after cleaning MS

Question asked by koos on Feb 14, 2019
Latest reply on Mar 3, 2019 by koos

Good afternoon everyone,


Over the last year, the EM volts of the MS have been slightly creeping up. Where it was still ~EMV 900 now we are roughly around 1800.

Since we had a bit of downtime, there was a chance of cleaning the MS source to increase the sensitivity.

The cleaning progress of the Agilent 5977B Operating Manual in combination with the How to clean an Agilent GCMS Ion Source  was followed.

The overall process went smooth and the source was looking (visually) clean after the process.


However after installing the source I did not notice any difference in the tune reports. Same EMV, same abundance of the ions.

And my question is how this is possible? I would expect an increase in performance after cleaning the source, but did not see any.

The tune reports are added


This all happened on a

5977B MSD

EI SS single quad

Fil 1 was replaced with a new one, Fil 2 was kept.

There is no difference between the old filament 2 and the new filament 1 in the tune reports.


Thanks for your time and a happy Friday,