Materials Girl: A watched TLC plate never rises
Posted on behalf of Materials Girl
It is my theory that organizations should raffle off spectrometers instead of, say, iPods. For example, various boxes of kimwipes have been advertising trips to Jamaica and home theater systems. While anyone could use a vacation, maybe we’d be stuck in lab less often if not for the long line to obtain an NMR spectrum…
Speaking of which, o-chem lab is going splendidly – apart from a handful of volatile lachrymators and an overcrowded class. I’d forgotten how semi-exhilarating it is to soak for half a day in the fumes of acetone and whatever concoctions are being nuked by the students. As suggested by Sarah, I got my hands on “Organic Chemistry as a Second Language”, but fortunately haven’t needed to use the books for more than a reference. I mostly just have to memorize peaks and trends for the exams. psi*psi was quite right: "Studying doesn't help for labs – you have to be able to think on your feet, since the unexpected can and does happen."
So here’s a question. In a week’s experiment, only one student obtains the desired powder (instead of an oil), but the NMRs come out messy after the higher-ups fail to mention that the product is hygroscopic and shouldn’t be dried in air. Who did a better job?
Comments
There are a billion and a half mistakes to make in the lab if no one tells you to avoid them. Example: don't use a steel needle with bromine. (I inherited a project from a former undergrad who was really surprised to get back a crystal structure with a few aromatic rings brominated.) Trouble is, it's hard to judge what the person you're training doesn't know--too much instruction can be helpful but may sound condescending. It's also not easy to keep track of exactly what they're doing at all times, which helps in giving advice. So many synthetic secrets are out there, too...it's impossible to go in knowing everything, so reading blogs can be really helpful for beginners. Org Prep Daily is probably the most useful in that regard.
If I could have my choice of free instruments...hmm...a solar simulator would be exceptionally useful (never mind how much aligning all the optical stuff sucks). I'd settle for a new vacuum pump, though.
Posted by: psi*psi | May 14, 2008 05:36 PM
Many mistakes are repeated year after year in undergrad labs. There is good information on NotVoodoo (just google that, then its Alison Frontier's pages) about how to avoid many common pitfalls in the synthetic lab from record keeping to reaction running. It would be a great blog actually 'common mistakes in synthetic chemistry and how to avoid them'.
I'd have a Kugelrohr if I could have a free bit of lab kit. Always wanted one, ever since I was frustrated by many contaminated liquid compounds during my PhD. Other than that, I'd love a MacBook Pro to add to my collection of computers and iPods. I think it would greatly improve my poster and website making duties!
Posted by: Propter Doc | May 15, 2008 11:36 AM