Chemical Forums

General Forums => Generic Discussion => Topic started by: Goala on September 25, 2012, 08:27:00 PM

Title: Making Mess in Lab
Post by: Goala on September 25, 2012, 08:27:00 PM
Hi guys,

I did my reaction in the organic chem lab the other day and I spilled some of my product.

Have you guys ever made "big mistakes" where you accidentally spilled some product?
Title: Re: Making Mess in Lab
Post by: discodermolide on September 25, 2012, 11:01:49 PM
Oh, yes. But I don't think I'll re-count them here!
Title: Re: Making Mess in Lab
Post by: OC pro on September 26, 2012, 02:49:15 AM
Oh yeah of course. But that´s normal don´t worry. Once I even had an exploding distillation. That was not so fun. And the second major accident was a hydrogenation of 250g starting material using Raney-Ni (~100ml suspension)  and hydrazine-hydrate which was added drop by drop. Somehow unfortunately, the reaction got exothermic spontaneously and everything came out with a splash. I had to scrub the hood for 2 hours and I felt quite uncomfortable because of the nasty chemicals.
And of course one ~250g Skraup quinoline synthesis was a big failure (it is worth to call it "The Chemical Inquisition" because the reaction is extremely violent). But at the end I had it under control (by cooling with a wet towel!!!) and got 75% yield which was extremely good.
Title: Re: Making Mess in Lab
Post by: fledarmus on September 26, 2012, 07:49:59 AM
There is a notation in my labbooks that appears occasionally - "benchtop extraction". This happens when I spill my compound over the benchtop, clean it up with some solvent and paper towels, and wash the paper towels back into a flask with more of the solvent. Typically this is followed by another chromatography to repurify the product, and is accompanied with very colorful language.

Accidentally spilled products happen in labs. What you do with it depends on the type of lab and the end use of the product.
Title: Re: Making Mess in Lab
Post by: orgopete on September 26, 2012, 07:54:29 AM
Hi guys,

I did my reaction in the organic chem lab the other day and I spilled some of my product.

Have you guys ever made "big mistakes" where you accidentally spilled some product?

I thought you were going to ask how to estimate the yield of the reaction. If you were, I was going to suggest the "equal spill" technique. If you had a liquid on the bench top, then you can pour water onto your bench top to estimate the volume, and subtract it from the amount you have. Solids can usually just be swept up.

If you need to recover it, you can do as fledarmus described.
Title: Re: Making Mess in Lab
Post by: synthon on September 26, 2012, 08:14:12 AM
Nope. Never, not once.    ;D
Title: Re: Making Mess in Lab
Post by: Goala on September 26, 2012, 08:24:36 AM
Awesome stuff! :)

Thanks guys!
Title: Re: Making Mess in Lab
Post by: 408 on September 26, 2012, 08:47:31 AM

Stupidest mistake was a 1L sep funnel full of ether where I had a temporary lapse in depth perception and when I thought I was setting it in a ring clamp, I actually dropped it about 8" in front of the ring.  I never figured out how exactly I did that. I had a flight 2 days after this.  never have I washed my clothes more thoroughly. (nitroaromatic in the ether)

Title: Re: Making Mess in Lab
Post by: fledarmus on September 26, 2012, 11:40:31 AM
In light of 408, perhaps I shouldn't mention that a number of spills I've had in my lab occured because I failed to check that the stopcock on the bottom of the sep funnel was closed before I poured in the mixture to be separated. And I feel your pain about the nitroaromatics!
Title: Re: Making Mess in Lab
Post by: 408 on September 26, 2012, 11:59:45 AM
The only time I ever did the stopcock thing was when telling the story to my labmates that I just told above. 
me: "yeah, I cant believe I did that " 
labmate:"dude you are an idiot, all I ever do is always leave the stopcock open"
me "sucker! I have never done that"

10 minutes later I for the first end only time leave the stopcock open.  :-[
Title: Re: Making Mess in Lab
Post by: zeved on September 26, 2012, 02:35:18 PM
in my first year of pharmacy in chemistry lab i was working without gloves (everyone was.. protection was a foreign word for that faculty..) and by mistake i suppose i spilt some sulfuric acid on my right hand and I didn't know it (I suppose it was low conc) and I sat on the bench with my right hand holding my head but the hand was over my mouth somehow and I suddenly felt my lips stinging a bit going worse and worse. next moment I yelled 'f&#^$*@ HELL' and all my coleagues were with their eyes pointed at me.. washed instantly with water and all was fine though..

however, I quit that university and went to chemistry department in another city. let's say I'm not that much into pharmacy and spending hours in H2S fumes and doing reactions that release NH3 and Cl without a fumehood is not among my favorite ways of doing experiments..

sorry for bad english..?

later: yes, I know I shouldn't have worked without gloves and definitely should have not put my hand around my mouth especially after working with H2SO4...
Title: Re: Making Mess in Lab
Post by: 408 on September 26, 2012, 03:08:05 PM
forgot this one...spilled (ok, gas leaked) a bunch of F2 in the lab.  we all know what it smells like and we all survived no problem.
Title: Re: Making Mess in Lab
Post by: SapereAude1490 on September 27, 2012, 04:11:25 AM
When I was a freshmen, I brought some matches to the lab. Chopped of the wooden part and put about 10 heads in a test tube, sealed it with cotton and applied heat.

When all the O2 burned, the red P turned to white P, I think. When I removed the cotton, the thing exploded a bit and there were tiny amounts of white P all around. Took them an hour to clean it. Do not do this at home. :D