I have recently encountered a problem in my bfb.u tune file parameters..
All of the sudden, my 5973 won't pass bfb tune (*inconsistent peek width*) (pic 1) though it passes Atune (pic 2) just fine..
Enclosed for reference are images taken from profile scan in manual tune
Atune profile scan
Bfb profile scan
* running MSD chemstation G1701EA E.02.02.1431
a few corrective actions I've run through already:
- filament change (both of them)
- column trimming (both ends), septa liner change
- Ion source cleaning (according to Agilent 5973 hardware manual document)
** haven't tried MSD baking (don't believe it would help)
We believe this bfb tune failure directly effects the following step of the VOC method of BFB P&T injection and running/ passing its test (pic 3)
It keeps failing at the same mass target comparison of 50 to 95... which led us to believe a problem exists with tuning at the lower masses..
*** While opening the MS for cleaning we noticed the quad mass filter heater assembly wires (only the two upper white ones) have been welded.. probably an old "fix".. so I am wondering if this could effect low mass selective..? of course, all temperatures are as they should be..
Will appreciate any input
Thanks in advance