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- Posts: 1
- Joined: Thu Sep 19, 2024 2:04 pm
- Location: Dallas,Texas
Ran the positive mass calibration using thermos's Peirce positive calibrant, but it failed due to not finding the MRFA peak at m/z 524.265.
I initially thought I could be the calibrants as they were old, so we bought new calibrant. No change.
I then thought I could be a dirt ion source etc. So, I cleaned the ion source housing, sweep cone, and ion transfer tube. Then flushed the system with 98% H2O + 0.1% formic acid (FA) and 2% MeOH + 0.1% FA for about half a day. No change.
Then flushed the system with 50:50, H2O + 0.1% FA:MeOH + 0.1% FA, for a whole day almost. No change.
My colleague suggested a system reset, which was performed....still no change.
-My worry is there may be some contamination deep inside the MS, that is breaking down MRFA as it is traveling through the system.
Does anyone have any ideas on what we could do next?
I initially thought I could be the calibrants as they were old, so we bought new calibrant. No change.
I then thought I could be a dirt ion source etc. So, I cleaned the ion source housing, sweep cone, and ion transfer tube. Then flushed the system with 98% H2O + 0.1% formic acid (FA) and 2% MeOH + 0.1% FA for about half a day. No change.
Then flushed the system with 50:50, H2O + 0.1% FA:MeOH + 0.1% FA, for a whole day almost. No change.
My colleague suggested a system reset, which was performed....still no change.
-My worry is there may be some contamination deep inside the MS, that is breaking down MRFA as it is traveling through the system.
Does anyone have any ideas on what we could do next?
