On my 5975 MS, the peak width for 219 on the standard autotune runs low. My range is 0.45 to 0.65. The 69 and 502 run above 0.50 but the 219 consistently runs 0.47 and below. Cleaning and maintenance are performed regularly. Filaments have been changed, repeller and drawout plate have been replaced, new PFTBA used, new autotune downloaded from Agilent hotline. My even older 5973 has no problems. Any suggestions?
Ion peak width and shape is related to the way the quadrupole functions and is tuned and not source cleanliness.
Have you reconfigured the system or loaded new software since it was installed?
The first thing to check is the quad dc polarity. There is a sticker on the analyzer that shows the optimum polarity determined by factory tests.
In the program Agilent GCMS Configuration the quad dc polarity must match the sticker.
So in this explanation, my DC polarity does not match the sticker. I would need to select Negative, save the configuration, which overwrites the default tune files, and then retune the instrument. I posted a document here in the Agilent Customer Community explaining DC Polarity (Quadrupole DC Polarity - what it means and how to check it ) .
If that matches, then we have other questions:
Are the tune ion peaks shaped correctly? Are they split or fronting?
How many samples have been run on this system?
What is the tune EM value? How old is the Electron Multiplier? <this is a customer replaceable consumable part, like tires on a car. If it is more than a couple of years old, you need to purchase and install a new one.
In the tune, it shows:
Notice that there is a Wid219 number. The AMU Gain and Offset numbers above it set the ion peak width for the entire range, and this number shows the compensation for the mid mass if the line is not perfectly linear. Also, notice that this tune report shows that the Pw50 -- the Peak Width at 1/2 height -- is 0.60 amu. This is the peak width that autotune (ATUNE.U) is trying to achieve.
Would you be willing to post a picture of your tune report? That will speed this up. The other way to handle this would be to call 1-800-227-9770 option 3,2,2
We have technical people ready to answer your questions from 8am to 5pm in your local time.