QQQ Collision Cell Gases On and Off

Version 1

    The Collision Cell gases, nitrogen and helium, are required for proper operation of GCMS QQQ 7000x and 7010x systems.

     

    7000x systems require 2.25 ml/min of helium and 1.5 ml/min of nitrogen.

    7010x systems require 4.00 ml/min of helium and 1.5 ml/min of nitrogen.

     

    The gas flows must be on during tuning.

    The gas flows must be on during all acquisition modes, including MS1/MS2 SIM and SCAN modes.  The collision cell gases slow down the ions as they fly from the source to the detector.  The scan speed correction factors are measured and calculated during tune and applied to the system in the tune file.  If the gases are on in tune and off in the run, the mass assignments will be incorrect.

     

     

    It can take ten to fifteen minutes or more after turning the gases on or changing the gas flows for the collision cell to reach equilibrium.