gc-ms Tune troubleshooting

Hi everyone,

Hi all, we have a problem when applying the Tune for the Agilent 7890B 5977A GC/MS instrument, it does not reach the end of the process and that causes a very high background noise, we have already cleaned the source (EI) and also we have put a new electron multiplier, and also the two filaments are working very well and even the level of PFTBA is correct. can you help us please?

  • Never, ever, ever rinse the quadrupole and HED with acetone or any other solvent. There is never a need for an operator to do any cleaning of the quadrupole.

  • You say that it "doesn't reach the end of the process."  Is the EM range error all that you see? Are there tune ion peaks on the screen at any time?

    In manual tune, turn the PFTBA valve on  - can you hear or feel it click?  You may need to turn it off and on a few times to be able to tell as some of them are very quiet.

    Load STUNE.U. If it hasn't been used it will be at the original default parameters but should still give peaks in manual tune with the PFTBA on and the filament on in Scan or Profile. They won't be optimized, big enough or with the right mass assignment, but peaks tell us something.  This eliminates the possibility of a corrupt autotune file.

    Did you verify that the column is not installed too far out of the transferline?  I install it flush with the ceramic transferline tip seal - so that it is not sticking out at all.  What is your column flow? Make sure it is between 0.75 and 1.4 ml/min.  

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