Optimizing drag field voltages in a collision cell for multiple reaction monitoring (MRM) tandem mass spectrometry

A mass spectrometry system comprising:

• a collision cell having:
• a plurality of rod electrodes arranged in opposed pairs around an axial centerline, and
• a plurality of drag vanes arranged in interstitial spaces between the rod electrodes, the drag vanes including a distal drag vane terminal and a proximal drag vane terminal;
• an instrument and data control system configured to:
• apply a rod offset voltage to the rod electrodes;
• vary a offset voltage applied to the drag vanes to identify a vane offset voltage with a maximum intensity for the transition;
• vary a drag field by adjusting the voltages applied to drag vane terminals located at a proximal end and a distal end of the drag vanes in equal and opposite amounts to identify a drag field value with a cross talk to an alternate transition below a cross talk threshold;
• vary the vane offset voltage by adjusting the voltages the voltages applied to the drag vane terminals by equal amounts to maximize the intensity of the transition while preserving the drag field;
• and
• operate the collision cell at the vane offset voltage and drag field to monitor the transition.