Ultramark

[beige_alert]

@#$%^%$%$#^ Ultramark



Still some Ultramark in the ion source even after, um, a month or so...



(Ultramark is used to calibrate Finnigan mass spectrometers. It’s sticky, and tends to stick around even after repeated acetone washes. Really, the ultramark isn’t our main problem right now. Our real problem is a big mass of strong peaks from an unknown source.)

Comments

[tigertoy.livejournal.com]

Um, I hate to burst your bubble, but I don't have enough context to interpret the graphs. What are they supposed to look like?

[beige-alert.livejournal.com]

I don't imagine that lots of Finnigan users are reading this and saying "Frickn' Ultramark!" but then popefelix probably doesn't have lots of people fascinated by his FREDdy Gamma Ray Burst notes, either. He's my inspiration for this kind of thing.

Anyway, this was a blank, so in theory the top graph, which is total signal (y) vs. time (x), ought to be pretty flat (since nothing was injected), and the bottom graph, which is the mass spectrum at a particular time (indicated by the red line in the top plot), and which is signal intensity vs. mass-to-charge-ration, shouldn't have much in it. A little noise, maybe a few low-mass peaks, not much since this was a blank injection. The series of evenly-spaced peaks at the right is in fact residual calibration mix from the last calibration, something like a month ago. You'd think it would all be gone by now, but no....