Chemists use glass; biologists use plastic. That's more true than not, because the biologists are using living (or recently living) systems, which like watery stuff. Plastic pipets and petri dishes are just fine. But over in chemistry, we're using ethyl acetate, dichloromethane, and DMSO, which will turn those items into cloudy, sticky ghosts of their former selves.
Usually the plastic and glass worlds coexist reasonably well, like planets of oxygen-breathers and hydrogen-breathers in a science fiction novel. But there can be trouble. A glass-for-plastic switch is no problem (unless you drop the thing on the floor), but the reverse can be messy indeed. I recall a friend of mine down the hall from me in graduate school, who was preparing to purify one of his precious compounds on the lab's HPLC system. As a good chemist should, he took up his compound in some solvent and filtered it, so as not to introduce grit and crud into the pumps or the chromatography column.
He picked up a membrane filter. They all look like disks of plastic, to be placed in a fritted glass holder, and they're all full of microscopic holes to let your solvent pass through. He poured his solution in, and watched in horror and disbelief as the white membrane filter dissolved and merrily sluiced through the glass frit along with his compound. Clearly the wrong kind of white plastic disk. I heard his shouted curses all the way down the hall.
Not too long before he had that experience, I had come to the end of my tether with my current batch of starting material. This was around step 18 or 19 of the synthesis, and I had just enough material for me to run one more step - two, if it actually worked well. I was getting down to some pretty tiny sample volumes (by the standards of organic synthesis, anyway.) But we'd just gotten some disposable 1 mL syringes in, and that looked like just what I needed to take my compound up in 100 microliters of solvent and add it to my carefully prepared reaction. (Remember, this was graduate school, and twenty years ago, to boot. A box of 1 mL syringes was an event worth noting in my lab.)
Came the moment, and I tried to syringe in my solution. But the plunger was putting up a fight - in fact, it was good and stuck. What I didn't realize was that this was one of the generic medical-supply syringes with the black rubbery tip on the plunger - for a good seal, you know, with blood and so on. Most organic solvents make that stuff swell up like a puffer fish, though, and I was just finding this out. I pushed harder. Nothing. I had to get that stuff in there, though, so I really put my thumb into the job, and SPLAT! The barrel of the syringe blew apart from the needle, and my compound sprayed all over the front of my shirt.
I didn't handle it too well. When I realized what had happened, which didn't take long, I started yelling and cursing, and then spotted a stack of cork rings. With plenty of venting left to do, I started throwing them out the door, with a different obscene adjective to accompany each one. My labmate, realizing that something was amiss, had already moved out of the flight path. But one of the inorganic chemistry professors was coming down the hall and just missed catching a cork ring in the ear. "Think I'll go around the other way," he said, taking a quick look around the door into my lab.
1. The Novice Chemist on January 21, 2005 9:32 AM writes...
Permalink to CommentGlad to hear that I'm not the only one who's gone crazy because of total synthesis. Derek, you give a man hope.