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Tuning an MSD 5973 to pass DFTPP Criteria
Posted: Fri Mar 14, 2008 8:13 pm
by EnvChemist
Help!!! I can't get an autotune to pass.
The peaks on my DFTPP tune look great and the breakdown passes perfectly however I am having some trouble with the relative abundances.
m/e 51 is just above 60%
m/e 127 is below 40%
Sometimes I can manipulate the target tune masses to get m/e within 40 to 60%, but I just can't get m/e 127 to pass.
My target tune masses are:
131 --> 26%
219 --> 30%
502 --> 2.2%
Any ideas ????
Posted: Fri Mar 14, 2008 8:16 pm
by AICMM
And the peak widths are???
Best regards.
Posted: Fri Mar 14, 2008 9:33 pm
by EnvChemist
0.5 amu
Posted: Mon Mar 17, 2008 3:36 pm
by darber42
I used to have trouble with this on a 5971. If your entrance lens offset is set to variable in your tune parameters, you can go under "Edit Dynamic Ramp parameters" and adjust the voltages for the individual masses. By tweeking the voltages you should be able to get a tune to pass.
Posted: Fri Mar 28, 2008 12:26 pm
by Bigbear
What method are you doing. I do EPA 525 and have found for me what works best is to use the option that allows m/z 442 as the base peak. I then run an autotune which usually results in too much 442. I then reduce the ion focus voltage ( usually about 20v) and inject DFTTP , tweeking the ion focus until DFTTP passes.
The DFTTP Agilent autotune does not work for me.
Good luck
Posted: Fri Mar 28, 2008 3:51 pm
by EnvChemist
Darber and Bigbear thanks for your suggestions ....
@ Darber I followed your advice and that worked for one of my instruments - the voltages were all over the place so I tweaked them to closesly match one of my other instruments and it worked! I was able to run samples for a couple of days, but now I'm faced with a new problem. No emission current!
@ Bigbear I run EPA methods 8270 and 625 and we only use m/z 69 as the base peak.