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Chromatogram doesn't look good
Posted: Wed Dec 07, 2011 8:44 am
by o0kim0o
Hi,
I'm quite new to this and my 5972 MS is not functioning the way I'd like it to function. I don't know what you need to know to make a verdict, but there are some things I need to point out.
autotune is failing. Even other tune files won't finish, saying the peaks are too wide and the offset is at maximum... at other times it will say it can't get a stable peak width or that there isn't enough signal to start. And when I run it at 2500EV it gives me this....
We're at our wits end...
Please help
Re: Chromatogram doesn't look good
Posted: Wed Dec 07, 2011 11:30 am
by nvalentine
Have you tried running at a lower voltage? 2500 seems pretty high to me.
Usually failing tune is a sign you need to do some source cleaning and maintenance and possibly switch/replace a filament.
Re: Chromatogram doesn't look good
Posted: Wed Dec 07, 2011 11:40 am
by o0kim0o
We just cleaned the source as mentioned in the manual and we even had an agilent specialist look at it for us.
We've just replaced the filaments too...
Re: Chromatogram doesn't look good
Posted: Wed Dec 07, 2011 1:50 pm
by o0kim0o
And has anyone got any clue why the baseline drops after 17 minutes, because it does so in every run?
Re: Chromatogram doesn't look good
Posted: Wed Dec 07, 2011 2:01 pm
by AICMM
o0kim0o,
1) Replace your EM. Then see what the tune does.
2) Replace your repeller and ion focus lens.
Hopefully this will get your tune to finish. When your autotune starts, how much 69 do you see?
3) build a real method, not the default. Set up real/realistic flows and split/splitless times. Keep it isothermal for now (say 50 C) but with a real column flow at less than a ml/min.
Then we go from there....
Best regards,
AICMM
Re: Chromatogram doesn't look good
Posted: Thu Dec 15, 2011 5:55 am
by mckrause
You either have a lens shorting out or you have a quad driver issue. Clean your source, and make doubly certain that you get it assembled correctly! I don't think you have an EM issue - peak width issues aren't resolved by increasing EM voltage. You may also have an EM issue, but that's not causing the peak width error.
You may have an issue with the quads on the '72. The glass quads are garbage. If you're good with hardware and have MS experience I'd recommend solvent rinsing them - if they get oil on them you can have all kinds of weird tune experiences. I've also seen them get so contaminated that you can't bring them back. It normally manifests itself as a mass issue - you can't set 219, but you have boatloads of 213. You can see this in scan - open the PFTBA valve and run a scan to see what your spectrum looks like.
Re: Chromatogram doesn't look good
Posted: Thu Dec 15, 2011 8:42 am
by o0kim0o
Well...
Now we can't even get the MS to turn on.
It keeps giving fault 8 even though we checked the filaments and the cables.
Everything seems to be okay, so we have no idea what's wrong
