3-30 Tuning the Instrument
Tips:
• The near-absence of m/z 285 indicates good CI conditions.
• It might be necessary to adjust the level of the reference compound
to fall below saturation of the TDC.
See also: Effects of saturation on peak shape on page B-51.
To adjust the level of reference compound, open the pump-out valve on
the reference reservoir slowly. The level of the reference compound
should be approximately 1000 counts per second in continuum mode.
See Also: General considerations for tuning on page G-6.
13. To obtain the best intensity of the 286 ion, retune these parameters in
the Tune window, CI Tune tab, Beam Steering, Focus1, Focus2, and
Focus3.
14. If required, also adjust the CI gas flow to obtain best sensitivity.
When tuning is complete, calibrate the instrument.
See also:
• Calibration on page 5-1.
• Dead time correction on page B-49
• Effects of saturation on peak shape on page B-51.
Turning off CI gas
To turn off CI gas
In the Tune window Inlet tab, clear the CI Gas check box.
Requirement: At the end of CI operation, the rotary pump must be gas
ballasted for 30 minutes.
See also: Gas-ballasting the rotary pump on page 10-5.
Tuning the instrument for negative CI
Note: MassLynx saves tuning parameters separately for each ion mode. In the
Tune window, ensure that the correct parameter values are set for the Inlet
tab, Engineer tab, and TDC Settings dialog box.
To Next Page
Loading...
