Flagged peaks (!) and failed calibration on Qtofs/Tofs - WKB10448

SYMPTOMS

• Calibration fails
• Flagged peaks ('!') are seen on the acquired data in the calibration window (or peaks are just not recognized as the Quartz-based calibration acquisition of SELECT SERIES Cyclic IMS has no flagging function for bad peaks)
• Happens with both sodium formate and sodium iodide

ENVIRONMENT

• Synapt G2
• Synapt G2-S
• Synapt G2-Si
• Synapt XS
• Xevo G2
• Xevo G2-S
• Xevo G2-XS
• SELECT SERIES Cyclic IMS
• MassLynx 4.1
• MassLynx 4.2
• UNIFI
• Quartz (Cyclic IMS)

CAUSE

Mass position is off

Spectral resolution on the instrument is either too low or does not match that set in Acquisition Settings

FIX or WORKAROUND

1. Check that V_eff is set correctly
2. Ensure that resolution and peak shape is suitably tuned for the mode used (sensitivity, resolution, or high resolution) using pusher offset and reflectron grid parameters.
3. Confirm that the Resolution field in the Acquisition Settings box is appropriate for the mode, but also similar to the actual resolution displayed by the instrument.
4. Rerun the calibration.

ADDITIONAL INFORMATION