Tuesday, November 2, 2010

Does research in chemistry teach you to be efficient?

I voted this morning (don't forget to vote!); what should have taken 2 minutes to confirm my identity, sign the signature page, etc took a lot longer. I walked in about 30 seconds after the polls opened, but it was quite clear that they hadn't gotten their system worked out yet -- sigh.

While academia is not really known for efficiency, I think that performing research in chemistry is one of many different ways to learn how to work quickly and effectively. You have a column to run, fractions to TLC and product to isolate; if you do this haphazardly, it will take 2 hours. If you do this efficiently, it will take 45 minutes. Which do you think is a better use of your time? I've also found that setting up a system to quickly perform a task is a great way of achieving some sense of "flow" and enjoying one's self in the lab.

Of course, not all of chemistry is about 'increasing sample throughput' or turning yourself into a robot; sometimes, it's about taking 2 hours to carefully stare down all your data. But if you've got a task to do, you might as well get a system in place and just do it. Here's to taking care of business in the lab, and here's hoping those poll workers get their system in place before noon.

9 comments:

  1. You can finish a column in 45 minutes? You're hired, I got two waiting for you right now!

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  2. WC Still's original paper on flash chromatography says 10 g of material can be separated in 10 minutes. Insert laughter here. Haha.

    JOC; 2923, 43, 1978.

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  3. Yeah, that Still paper just cracks me up. It makes it sound sooooo damn fast!

    This, on the other hand, 10g in 15 minutes is totally do-able (assuming you have generous Rf diffs)

    http://curlyarrow.blogspot.com/2008/01/dry-column-vacuum-chromatography-dcvc.html

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  4. E-s, have you actually used that method? I showed it to my boss a while ago and downloaded the paper, but we're still not sure how generally user friendly it is.

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  5. Yes, regularly. I use it for anything over ~ 5g. Just like flash columns, the first 3-4 times will be a cluster*, but after that it's worth it. If you have a glassblower, it's nice get an adaptor like chembark's, as it saves you having to disconnect the tubing for each fraction.
    Impt details: make sure you have the right size silica! I also add a layer of sand on top, and then a filter paper, so pouring new solvent doesn't make channels. My method: pull 2 fractions with pure hex or pet ether, then increase each one by 5% of whatever your polar solvent is.

    IMHO, it is most worthwhile if you have a big scale reaction with lots of by-product crap (Mitsunobu, HWE, etc) : just rotovap down the whole mess crude, load the oil/sludge, and off you go.

    Very often you can purify 15-20g fast, and get it pure enough to recrystallize and be done with the the whole sheebang in a morning. It saves lots of solvent too.

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  6. (oops, "chembark's" above should be "curlyarrow's")

    Also, I should have made it more clear: you *can* get separations that are just as good as normal flashing, and it works great for 2-4g, I just don't tend to use it for either of those situations.

    The Aldrich ChimActa article is also quite good.

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  7. The dry column take does work well, in my experience. Used to use it to separate 10-20g of oligo-saccharides after a few flubbed attempts.

    Also nice in that didn't need to watch it as closely as a flash column (which would be more fun had I had a trained monkey to collect fractions and refresh solvent resevoir...)

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  8. groan. I spent four hours purifying 12 g of a pyridyl quinoxaline derivative using FC. It took around 3 L of MeOH-EtOAc. Wish I had the bucks for one of those DCVC-setups. At least the separation was good :-)

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  9. You don't need the fancy setup! Just use a frit! The correct silica is the only thing you need to scrounge, beg, borrow or steal. All the rest is just gravy.

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