Hi, we have an LC/MS Ultivo G6465B and recently we saw huge signal intensity drop in dMRM mode (NEGATIVE). After this, we obtain Autotune “Out of Tolerance” for several times.
We performed the following processes:
Nebulizer (capillary) cleaning with high flows (5 ml/min) and sonication using various solvents, ion source cleaning, including ion transfer capillary, cleaning and verification of the calibrant delivery system, replacement of the calibrant solution with a new one, replacement of the ion transfer capillary with a new one. None of these processes has resulted in a signal increase in dMRM.
After all of this, it is decided to analyze again the sample in dMRM mode (NEGATIVE) but changing the resolution of the first and second quadrupoles in dMRM method (We always work with a resolution of 'Unit' in both quadrupoles). Different combinations are tested. In summary:
It is observed that changing the resolution from ‘Unit' to ‘Wide' in both quadrupoles increases the signal intensity.
It is observed that further increasing the signal intensity occurs when changing the resolution from Wide' to Widest' in both quadrupoles (good signal values).
The signal stays high (good values)when we set the first quadrupole to 'Widest' and the second one to 'Unit' resolution.
The signal drops significantly when the first quadrupole is set to 'Unit' resolution and the second one to 'Widest’.
I would appreciate any suggestions to be able to PASS Autotune again. Thanks!