Negative ion tuning problems on a Sciex API 3200

[Jsup]

While performing our mandated monthly tune I'm finding that one of the instruments will show only the peak for the 49amu mass, showing nothing for the higher masses. We're using the 3x10-4 PPG Neg solution and positives look fine and pass specs. No amount of fiddling with instrument parameters seems to help. Maybe a problem with Q2 not fragmenting?

[yangz00g]

Check your DAC for each mass and compare them to last tuning. But don't make any change before you know how (call the service hotline ) and feel comfortable about it. Hope this helps.

[Jsup]

thanks! The problem wound up being the offset for each mass. By moving them way up and down we were able to find the peaks and then fine tune them into acceptable specs.