•
The trap temperature may be too high to allow you to observe all of the
Cal Gas ions. Reduce trap oven temperature to 150
°
C, and wait for
thermal equilibrium.
Check the RF Adjustment
Check whether an RF ramp adjustment is needed.
Check the RF Storage Level
Check whether the RF storage level is incompatible with the scan range.
Check the Trap Temperature
Check whether the trap temperature is too high to permit you to observe all Cal
Gas ions.
If the trap temperature is too high, the height of the mass 614 peak may be
reduced, and the mass 502 peak may disappear entirely (above 200 °C). Reduce
trap oven temperature to 150 °C and wait for thermal equilibrium.
Poor Resolution with Acceptable Air and Water
Levels
If the peaks are broader than you would have expected, you should investigate
the following possible causes:
•
There are too many ions in the trap (i.e., contamination or high column
bleed).
•
The supplemental waveform value is too high or too low.
•
Supplemental waveforms are not functioning properly.
Check the Ion Content of the Trap
With the trap turned on, note the TIC (total ion current) value. If the TIC value
exceeds 20,000 counts in full-scan mode, reduce the number of stored ions.
Run Auto Tune
If problems with the supplemental waveforms are suspected, run the Auto Tunes
to reset these values.
Troubleshooting High Baseline at High Masses
If the baseline on the Manual Control page increases sharply between masses
400 and 1000, there may be particles on the electrode surface.
Check for Particles in the Trap
In Manual Control, activate C:\VarianWS\4000 MS Service\4000 MS (Int or Ext)
Service.mth, go to segment 2, and turn the Trap on and the Ion Source off. If the
trap is free of particles there will be no significant spiking above the baseline and
the base amount will be less than 10. If spiking or a base amount greater than 10
is observed, the system should be shut down and the trap cavity and manifold
area should be blown free of particle matter using a compressed inert gas.
104 of 127
Summary of Contents for 4000 GC
Page 4: ......
Page 40: ...6 of 127...
Page 77: ...3 Check source connection pins for proper alignment and straighten as necessary 43 of 127...
Page 124: ...90 of 127...
Page 148: ...114 of 127...
