18
CI Gas Adjustment
Before performing chemical ionization, adjust the reagent gas pressure. The next
section explains the set up of the most common reagent gases.
Air/Water Check
Too high a pressure of air or water in the system because of an air leak or a
need to bake out the system will result in poor performance. This checking
routine gives advice on the levels of air and water.
NOTE: The Air/Water Check uses the electron multiplier voltage giving a 10
5
gain, not the manual setting. After replacing the electron multiplier, auto tune of
Electron Multiplier
before
performing the Air/Water Check.
Setting Up CI Reagents
Before running CI experiments, adjust the CI gas pressure.
To adjust the CI gas pressure, do the following:
1. Click
the
Checks and Adjustments
tab of the Manual Control window.
2. Select
CI Gas Adjustment
. Select your CI reagent from the drop down box
in the Parameters section.
3. Click
Start
below the adjustments selection.
4. The criteria for adjusting the flow of CI reagent into the instrument are shown.
5. After completing this, you must perform a mass calibration and trap function
calibration before beginning your experiments.
Summary of Contents for 4000 MS
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