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3
CI Troubleshooting
The filament or filament support is shorted to the ion source body or
repeller.
Inspect the filament. If necessary, realign the filament support arms.
The electron inlet hole is blocked.
Inspect the electron inlet hole. If necessary, clean the hole with a clean toothpick
and a slurry of aluminum oxide powder and methanol. If the electron inlet hole is
that dirty, the entire ion source probably needs to be cleaned.
Saturated methane/isobutane gas purifier
Replace the gas purifier.
Poor quality methane (purity below 99.99%)
Replace the methane with high-purity methane. If necessary, clean and purge the
reagent gas lines and clean the ion source.
No or low PFDTD signal, but reagent ions are
normal
You are using any reagent gas but methane in PCI.
Switch to methane.
Wrong or corrupted tune file loaded
Check your tune file.
No PFDTD in the calibrant vial
Inspect the calibration vial on the GC side of the MS. If necessary, fill the vial with
PFDTD. Do not fill the vial completely; keep the level at least 0.5 cm from the top
of the vial.
The pressure of the methane entering the flow controller is too high.
Make sure the regulator on the methane supply is set to 20 to 25 psi (138 to
172 kPa).
7250 Accurate-Mass Q-TOF Troubleshooting and Maintenance Manual
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Table of Contents
Troubleshooting
