Hi, does anyone ever get adamantane from the rotor sublimate and condense outside it?
A student here found a suspicious white powder on the stator.
He tested airflow for particles and nothing was found in the incoming air sources. So the suspect is adamantane or something else from inside the probe. He said that when rotor grinds itself the resulting dust is dark in color.
Have you seen anything similar?
It's conceivable (adamantane, of course, does sublime) but I've never seen it happen and think that it is unlikely. You don't mention the sample temperature history, that is, how much time has the adamantane sample spent at what elevated temperature?
I assume that the rotor has standard ceramic-to-plastic pressed fit closures. Are they tight? Are they good and tight? If so and the sample temperature has not been elevated, then the probability of adamantane escaping is low.
In my own experience, dust/powder/etc. has always been attributed to wear-and-tear from a rough running rotor, left over material from a (sometimes surprisingly old) previous sample spill, an errant sample cap permitting dispersal of a sample or gunk (not always oily) from the spinning gas source.
A generous splash of methanol (mild solvent, safe to most plastics, no water, quick to evaporate) with the probe held so that the solvent drains away from anything in the probe, some gently but vigorous rubbing with a cotton-tipped applicator, a a good and sustained whoosh of compressed air (from the outside and from the spinning gas lines) is usually effective for removing such debris without screwing up anything else.
answered May 31 '10 at 06:25