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Tuning issue
Posted: Tue Oct 05, 2010 5:00 pm
by gyy54
I have Agilent LC/MS G1946D, I met a tuning problem, autotune failed with "Peak width adjust error: unable to adjust widthoffset for tune mass 118.08.".
I tried to do a manual tune, the situcation was: no peak was found at low mass 118.09, other mass were found but shifted a lot, for example: mass 622.03 shifed to 636, mass 2121.93 shifted to 2163.
Mass axis calibration won't solve the problem.
What should I do to solve the problem?
Posted: Tue Oct 05, 2010 6:31 pm
by bhuvfe
Maybe try to reset to defaults value and restart the autotuning.
Do you have a lot of noise in the low mass region?
Posted: Tue Oct 05, 2010 9:04 pm
by gyy54
Maybe try to reset to defaults value and restart the autotuning.
Do you have a lot of noise in the low mass region?
Thank you to reply my issue.
I did reset to default value but not work. the noise was not high in the low mass region, actually I did a spectrum scan, all the messes were found except mass 118.09, my scan range was set 50-3000.
Posted: Wed Oct 06, 2010 6:16 am
by bhuvfe
Few thoughts.
Is the tuning mix fresh?
Is the fragmentor voltage as it should be?
What about the intensity of the other ions? Are the intesities decreasing compared to previous tunings?
Posted: Wed Oct 06, 2010 6:16 am
by bhuvfe
Few thoughts.
Is the tuning mix fresh?
Is the fragmentor voltage as it should be?
What about the intensity of the other ions? Are the intesities decreasing compared to previous tunings?
Posted: Wed Oct 06, 2010 3:04 pm
by gyy54
Few thoughts.
Is the tuning mix fresh?
Is the fragmentor voltage as it should be?
What about the intensity of the other ions? Are the intesities decreasing compared to previous tunings?
Tuning mix was ordered recently.
fragmentor voltage was showed "VAR" in manual tune.
The intensity of all other mass was quite high and not decreased during manual tune, the baseline noise was very low.
Posted: Wed Oct 06, 2010 4:22 pm
by bhuvfe
Maybe you can try to bake the system overnight and try again.
Looking at the intensity of 118 from a previous tune file,
do you see any other peak in the region 110-130 with a similar intensity ?
If you have another nebulizer try to switch it and see if it has any effect (if the calibrant on your system is delivered through it and not directly on the top of the spray shield)
And if all of the above doesn't work I think that you'll have to vent and clean the capillary.
Good luck.