Column Chromatography It will take considerable practice to master the art of “running a column”. This video will get you commenced, with guidelines on choosing proper conditions, packing and running a column, monitoring separation, and even generating a micro-column from a pipet. View the total course: ocw.mit.edu License: Innovative Commons BY-NC-SA Far more data at ocw.mit.edu A lot more courses at ocw.mit.edu
UK chemists have written to Prime Minister David Cameron over funding cuts in the field of organic chemistry. The Professor explains why. And here’s a link to a letter The Professor himself wrote to Margaret Thatcher… periodicvideos.blogspot.com More chemistry at www.periodicvideos.com Comply with us on Facebook at www.facebook.com And on Twitter at twitter.com
Video Rating: 4 / 5
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really helpful with my chemistry class. good job. thanks a lot.
great vid. . I learned a lot about column chromatography. . thanks pal!
The way she shows us the video is so funny
fml i dont undrestand nothing about this…im so screwed
use heptane, better for the environment
“There are also columns available with sintered discs at the base to avoid the cotton and sand part”
Speaking of which, I was just watching a column video that involved such a sinter, and the top of the column was bent, whereas this one is flat. indicating that care can overcome better equipment.
“why is a layer of sand used on top of the cotton?”
“To make sure the silica gel is flat on both sides (the bottom of the column isn’t flat if you don’t add sand over the cotton)”
There are also columns available with sintered discs at the base to avoid the cotton and sand part
Having to collect 100+ fractions and spot all of them on TLC only to realize you didn’t get enough separation. Having the column fissure right after adding your precious sample and having to recover every bit you can rotovapping down tons and tons of solvent praying you can get everything back. ughhhh never again please!!
@HelloBrainMind An automated system like biotage.
I wish I had this video when I was an undergraduate. Its every bit of knowledge I eventually sucked up while running tons of horrible columns separating cis trans isomers that would barely separate and took forever. One thing that I didnt notice, she may have mentioned, is that dissolving silica in polar solvent is exothermic and can heat the silica enough to make fissures and ruin the column. Watch out!
Great video!
This is really interesting. Thanks for this vid
nice beakers
@534Anthony To make sure the silica gel is flat on both sides (the bottom of the column isn’t flat if you don’t add sand over the cotton)
why is a layer of sand used on top of the cotton?
great video, really helped, excellent intro for new ppl
thank you.
Nice video!
But I still hate running columns
@gshivashimpi77 you are wrong my friend.
hexane,EtOAc or a mixture of them and likewise chloroform and methanol are the most common solvent systems used but it all depends on the mixture you want to separate…
STILL don’t understand this.
So if you have a solution of two compounds that are closely related in polarity this makes sense, but how do you scale this up? ?!?
Ughhhh.
@steeeee33z thank you!!!
debussy arabesque no.1
whats the music in the beginning of the video?? anyone know plz tell me, been looking it for years..
realy nice work
In this video it is been told that, to make slurry of silica gel, use the chosen solvent mixture. That is totally wrong. Actually one should use least polar solvent among solvent mixture (Like Hexane in Hexane/EtOAc system and Chloroform in Chloroform/Methanol system etc). Other things are perfectly explained.
This is wonderful.
your hands work faster than your words…in my country they do it vice versa…thanks God we still have a good lecturer like you…
Great refresher video… Thanks a million, MIT
Now, with a little luck there’s a lecture here somewhere on GLPC
@Yeahrrrrrr55
Martyn’s hair.
you need to start making gold voila!
We need a Occupy Chemistry Movement.
whats the difference between a mad scientist and a mad engineer?
not mad as in angry, mad as in comic book superhero crazy.
@lordvesel Brady would be asking what a non-chemist would be asking, so yeah, he is just playing devil’s advocate.
@40390576
uninteresting point of view. do U know what U R doing? it is called colonialization .. not known in the place U R coming from …
jugde Urself .. use mirrors .. talk about Urself ..
i did not ask U and Ur poor head pointing out Ur opinion, mr. cifre, sir
@vuotopiuscuro
You, sir, are nothing but a troll, and I’m impressed by the patience of the people who have tried to educate you. You have been hoping and praying that someone will take a cheap shot at your deliberately idiotic spelling and willfully ignorant statements, but they are too clever for you. Why not go spam the ‘Moon Hoax’ conspiracy channels? I’m sure you’ll feel more at home there, among your own kind. You’re certainly out of your depth here
What annoys me, is how we’re given the impression that all areas of public spending are being cut. The government are reducing the size of our milatary and the technologies they use, the NHS is in the news loads, as highlighted in this video money given to fund research, and spending on education is being reduced.
BUT the Bank of England are able to create £75bn to try and boost the economy, but by giving it to the banks…who are probably now laughing while sitting in solid gold underpants.
you god freaks are beyond pathetic, if it was up to you the world would still be flat and penicillin would be unheard of, idiots…..
I do hope the cameraman (can’t remember his name at the moment) is just playing devil’s advocate in this video.
@UnbiasedIntellectual I hear you man. Free thinking is so not worth it, lets people come to ideas that weren’t explicitly divined by God. I wouldn’t mind establishing an authoritarian church and bringing every human under its regime, no one would have rights, but at least god would be happy.
@BlackSphinxGG “It’s sound and smart.” I think you have stumbled on the reason why it will never happen.
@onimotoko the faith schools i thought he was mentioning don’t do science, they twist it and teach their twisted creation. as long as someone is capable of performing pure and unbiased science, let them have their funding. but faith tends to corrupt science, prompting one to start with a conclusion and move towards proving it right, instead of starting with facts and moving to find an explanation.
what the.. who thought it was a good idea to cut the line of chemistry that’s improving health, it would make way more sense if they chose to cut a line that improves convenience or satisfies curiosity..
Not that I would like any line of science to get cuts.
Oh well, politics are not supposed to make sense.. In any country
@corvusatum
/index.php?db=comics&id=2072#comic
Go to smbc an type that after “com”.
Besides, that’s physics.
They can fund homeopathy but not legit science? ಠ_ಠ
TINY
@coolliger If you understood exactly what Science was, and what Faith is, you’d understand the obvious tension between the two. Although I do agree I don’t see much of a point to Religion Bashing on a video that’s about Science Funding, I can understand where they’re coming from.
Having government make decisions about what should and shouldn’t be funded really has nothing to do with reality. In a free-market economy, and it’s even questionable if the US is that, it becomes very clear where we put money: If it sells, we fund it. Nobody in government has any idea what works in the marketplace, even marketers can’t get it right. If government allows a free market to determine spending, we will have a much better system.
@collegehumorrules The questions were planned, as they are the most common questions general people will ask, so actually it’s quiet clever, It gave the professor a chance to put down and answer the most common come backs.
We all know, the foreign aid budget is the biggest waste. billions a year given to other countries that are in fact capable of looking after themselves
while peers can review in secret, they know who they are reviewing (often times reviewing other scientists within the same field- who may be their friends or competitors)…
@MyNamesNotLuke Keep telling yourself that. For how long out of 100,000 years of human existence have the majority of beings been educated and politically empowered? It’s not even true today when you include the huge regions controlled by warlords and dictators. Women only got the right to vote in the US 100 years ago. Civilization is a fragile thing, and as wealth continues to concentrate in fewer hands, the infrastructure will continue to collapse and things will continue to degrade.
@treemarble Yeah, it’s completely retarded. It makes no sense. They call it decriminalized, but only if it is a small amount and out of public view. And if you are searched by an officer and he finds it, it is no longer considered “out of public view” so yeah, you’re not the only who doesn’t get it. I guess they just passed that law to confuse people on the legality of MJ, it’s the only reason I can think of.
@from212 “Small amounts of MJ has been decriminalized here in NY but I was still arrested since then for a single baggie, and fined $250. It was actually better when it was criminalized, you used to get out the dame day with a 6 month DAT and no fine.The Laws are so screwed”
IMO this isn’t decriminalization.. perhaps a ‘civil’ offence ?! ….am unsure [ I reside outside USA]
-decriminalization infers attention by ‘law’ toward cannabis would be akin to say the same as ..nettles or dandelions..