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Thermo Fisher Scientific

Low sensitivity


Low sensitivity


  • GCMS


  • For TSQ systems working in SRM mode, check the quality and pressure of the Argon for the collision gas. Purge thoroughly the line if required.
  • For systems working in CI mode, check pressure and quality of the reagent gas. Purge thoroughly the line if required.
  • Perform an EI Full Diagnostic tune. If it is correct:
  • Perform an Autotune (SmartTune or EI Daily Tune or EI Standard/SRM Tune) and troubleshoot the column installation, inlet leaks and syringe status. 
  • If it fails, troubleshoot accordingly to the errors: o Ion source errors (lens1/2/3 and repeller): Extract the ion source, seek for issues or damage and clean it.
  • Check the lens springs ceramic plate for damage or cracks.
  • Check short circuits at the ion source housing and damaged insulators.
  • Electronics failures. Troubleshoot the board related to the error.
  • Detector failure. Troubleshoot accordingly.
  • Replace the electron multiplier if the Voltage is above 1800V.


  • Main causes are dirty or incorrectly assembled ion source
  • Damaged spring board
  • GC carrier gas leaks or syringe malfunction
  • Ion source housing short circuits
  • Lens board issues
  • Other electronics issues and multiplier fault


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