Hi
LC-MS/MS 6490 has run a method withour problems. For the last months, in that method, it stops recording MS signal for about 1.5min then resume. This happens at different RT. It keeps drifting from injection to injection.
Any idea what it could be?
Thanks
Figure: TIC. No signal (or very weak signal) between red arrows.
Figure: Zoom previous TIC. No signal zone circled