tag:blogger.com,1999:blog-4387100009341358284.post1267938017511949082..comments2024-03-12T09:55:15.923+01:00Comments on Curly Arrow: Dry Column Vacuum Chromatography (DCVC) - The Movie!Daniel Sejerhttp://www.blogger.com/profile/12498255536497699232noreply@blogger.comBlogger23125tag:blogger.com,1999:blog-4387100009341358284.post-13053118446356090442021-05-26T17:40:07.365+02:002021-05-26T17:40:07.365+02:00Hi Sara,
That is really interesting and I have ha...Hi Sara,<br /><br />That is really interesting and I have had the thought myself in the past and others have also suggested it. We had a big box of prepacked columns back at Uni. that I considered using for DCVC but I couldn't figure a smart way out for setting it up. As far as I recall the prepacked columns have a small particle size suitable for DCVC and are quite compact. Basically ideal Daniel Sejerhttps://www.blogger.com/profile/12498255536497699232noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-34878757347421570022021-05-26T11:33:00.850+02:002021-05-26T11:33:00.850+02:00Hi Daniel!
Have you tried DCVC with prepacked col...Hi Daniel!<br /><br />Have you tried DCVC with prepacked columns? I've always struggled a bit with the packing and now I'm in a new lab where we have a lot of prepacked columns from RediSep, for a CombiFlash instrument that has been broken for a while and will not be replaced. The packaging doesn't state the particle size, but I'd assume it's 35-70 microns from their website. Sara Björkhttps://www.blogger.com/profile/02734002199048384175noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-74458089535532046952020-02-17T19:02:50.043+01:002020-02-17T19:02:50.043+01:00Hi SAB, great that you are finding it useful. Yes ...Hi SAB, great that you are finding it useful. Yes I always distribute the crude sample evenly on the surface and almost always after absorbing it on Celite. D!Daniel Sejerhttps://www.blogger.com/profile/12498255536497699232noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-12038717868971223322020-02-17T15:16:59.754+01:002020-02-17T15:16:59.754+01:00Greetings, Daniel -
This is truly an invaluable r...Greetings, Daniel -<br /><br />This is truly an invaluable resource you have created. I am doing larger volumes, having been inspired by you... At one point in the https://www.reddit.com/r/chemistry/comments/5v5qq1/dry_column_vacuum_chromatography/, you mentioned that you have done upwards of 200g. I’m curious- do you distribute the crude over the entire surface of your silica, so as to Solidspinhttps://www.blogger.com/profile/05551039089168057384noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-603919241708203562020-01-27T19:41:06.531+01:002020-01-27T19:41:06.531+01:00Hi Greg, the short answer is no. From a practical ...Hi Greg, the short answer is no. From a practical aspect the fraction size needs to increase with increasing column diameter. As you can see in the video ca. 25 ml works well for a column id of 3-5 cm. For id 5-10 cm you have to go up to about 50 ml and so on. It will be self evident when you try it out whether the fraction size is too small. How large you can go with the fraction size depends onDaniel Sejerhttps://www.blogger.com/profile/12498255536497699232noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-86906565862633361082020-01-27T19:25:44.187+01:002020-01-27T19:25:44.187+01:00I am trying separations on C18 silica with an etha...I am trying separations on C18 silica with an ethanol: water:acetic acid solvent in order to be green. Is there a rule of thumb to size the fraction and sample size vs the CV of the reverse phase system with known rf values?Greghttps://www.blogger.com/profile/00888423481619515189noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-64949587436046049742019-06-08T23:47:35.232+02:002019-06-08T23:47:35.232+02:00Hello
first of all, thank you for the impressive v...Hello<br />first of all, thank you for the impressive video. I did the same for fractionating my 10 gr plant extract. Although I fractioned the extract with much less solvent and silica than Flash, I had some trouble in the process; the bands didn't come down in a straight line! they came down as a curve which made the separation much poorer than it should be. does this relate to how I pouredZarynoreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-71542205136965096022019-01-28T09:35:29.717+01:002019-01-28T09:35:29.717+01:00Hello Daniel, I'm not sure if you still watch ...Hello Daniel, I'm not sure if you still watch this blog but I figured it doesn't hurt to try so, I love the video, watched it quite a few times just to make sure I didn't miss any subtle details or anything (like a normal chemistry novice would do ) so , thanks Daniel , it's a great help. I do have a question in regards with running the column though. You say you always use thrdelhttps://www.blogger.com/profile/06932878102971118958noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-31821033066626082992018-11-28T22:07:12.612+01:002018-11-28T22:07:12.612+01:00Hi, and thanks for the great video.
Are drawin...Hi, and thanks for the great video. <br /><br />Are drawings available to guide a glass blower for making the DCVC adapter for the Buchner funnels suitable for smaller funnels (1-8 cm id) and larger ones (10-20 cm id). By adapter I mean the custom glassware that combines the functions of a sep funnel, vacuum take-off and Buchner adapter that fits the rubber bung. <br /><br />Finally, there is Anonymoushttps://www.blogger.com/profile/03587466274025287356noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-80821222613200309962018-04-24T15:45:38.741+02:002018-04-24T15:45:38.741+02:00@Nicolau: That is awesome. It's good to hear t...@Nicolau: That is awesome. It's good to hear that the people around had an open mind and where willing to give it a shot. It really is an excellent purification technique to add to the synthetic organist chemists purification tool box. I'm looking forward to the citations ;-)<br />Regarding large scale purifications these are just more of a hassle. The biggest "problem" is to Daniel Sejerhttps://www.blogger.com/profile/12498255536497699232noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-60714715470004366952018-04-13T15:10:45.182+02:002018-04-13T15:10:45.182+02:00Hello again, Daniel! It is my great pleasure to sa...Hello again, Daniel! It is my great pleasure to say that in the past half a year since I posted here, I've started a movement in my lab towards DCVC (Merck still sells 115111 silica after all). After a lot of work convincing labmates to try it out (and supervisors to invest in the idea), it's starting to take hold! You can count on multiple future citations and positive word-of-mouth.<br Nicolaunoreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-66420578964578476982017-12-12T10:39:41.220+01:002017-12-12T10:39:41.220+01:00This comment has been removed by a blog administrator.Anonymoushttps://www.blogger.com/profile/06518296269270702129noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-75731968621272227692017-12-12T10:38:58.761+01:002017-12-12T10:38:58.761+01:00Hi all, I've used this technique on small scal...Hi all, I've used this technique on small scales 1-5g and I find it works well enough. However, when I've tried larger scales 50-100g I'm finding that there is very wide bands and co elution of spots that are quite well separated by TLC. I've loaded 50g of crude onto a 12cm sinter with a round 6cm of well packed silica. Gradient elution was carried out by increasing from 100% Anonymoushttps://www.blogger.com/profile/06518296269270702129noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-72439192345022093462017-12-12T10:38:38.241+01:002017-12-12T10:38:38.241+01:00This comment has been removed by a blog administrator.Anonymoushttps://www.blogger.com/profile/06518296269270702129noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-14102882214601900802017-11-09T15:46:18.038+01:002017-11-09T15:46:18.038+01:00@Nicolau, I am not a chemist but enjoy the seperat...@Nicolau, I am not a chemist but enjoy the seperations. I routinely use the method shown here on this blog for refining plant extracts that are legal here in Oregon. I found suitable gel on Amazon although not as small as Daniel demonstrates in particule size. So long as I take care in packing the column well the seperations are excellent on an extract with such a great many compounds present. Anonymoushttps://www.blogger.com/profile/03257305937560683316noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-18032988324686693372017-11-09T15:35:00.466+01:002017-11-09T15:35:00.466+01:00@Nicolau: I don't have a quick answer to your ...@Nicolau: I don't have a quick answer to your question. When I Google it I find vendors that have this type of silica in my part of the world. As long as you get the particle size about right it's worth a shot. Some brands prefer to use mesh or microns to describe the silica so you should find a conversion table online and go hunting for the right type of silica. D!Daniel Sejerhttps://www.blogger.com/profile/12498255536497699232noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-36499866810833244652017-11-08T23:50:22.597+01:002017-11-08T23:50:22.597+01:00Hey Daniel, thanks a ton for your very detailed ex...Hey Daniel, thanks a ton for your very detailed explanations and video. I am interested in trying DCVC, but I can't seem to find the correct kind of silica. In your published article, you use Merck 15111 silica gel 60 (15–40 um), but the product seems to have been discontinued since then. Can you provide a link to an alternative that would work equally well?Nicolaunoreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-84767882741139204642017-03-10T10:18:32.074+01:002017-03-10T10:18:32.074+01:00There is an interesting discussion on DCVC going o...There is an interesting discussion on DCVC going on at Reddit worth checking out: https://www.reddit.com/r/chemistry/comments/5v5qq1/dry_column_vacuum_chromatography/<br />D!Daniel Sejerhttps://www.blogger.com/profile/12498255536497699232noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-20540731222227332182017-03-08T15:27:48.076+01:002017-03-08T15:27:48.076+01:00Great video and great to see you back Daniel. Your...Great video and great to see you back Daniel. Your blog was great help to me during my PhD and I tried DCVC a number of times!xmac1xnoreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-33036638779357749512017-03-01T14:26:28.967+01:002017-03-01T14:26:28.967+01:00Hello from Oregon USA, and thank you so much for t...Hello from Oregon USA, and thank you so much for taking the time to pass along this great video. It turns out that I had resorted to this idea on chance as I was purifying some plant extractions. I tried with my hobby grade chromatography tube to get seperation but needed a way to do this much more efficiently and scalable to my process with normally requires 28 grams or so at a time to be Anonymoushttps://www.blogger.com/profile/03257305937560683316noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-34801200303470190212017-02-21T16:10:39.925+01:002017-02-21T16:10:39.925+01:00In my previous job I used DCVC a lot. I had the gl...In my previous job I used DCVC a lot. I had the glassblower modify some glass filter funnels to be taller. I used them in several diameters, up to about 10 cm, and separated up to about 50 grams of crude per run (as I recall). I also used the system with butanol-acetic acid-water to separate some very polar compounds.emunfredhttps://www.blogger.com/profile/02023467087670508823noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-503434154828188182017-02-21T12:51:42.720+01:002017-02-21T12:51:42.720+01:00@Mike Krigg: I doubt that I will ever get back to ...@Mike Krigg: I doubt that I will ever get back to posting on the level I used to. I simply have too many things to do these days. However, I have been considering if I should start sharing my groups research on the blog if nothing else. Let's see if I get inspired. I have on many occassions encouraged students to write blog posts but they aren't really interested. However, it is still a Daniel Sejerhttps://www.blogger.com/profile/12498255536497699232noreply@blogger.comtag:blogger.com,1999:blog-4387100009341358284.post-21508589552300610182017-02-21T08:16:01.911+01:002017-02-21T08:16:01.911+01:00Its great, gonna watch it soon (After I set up rea...Its great, gonna watch it soon (After I set up reactions :D )<br />Is there any chance you will post more again on your blog? Lot of interesting stuff here but it seems that it slowly died :(Anonymoushttps://www.blogger.com/profile/08498833113002362344noreply@blogger.com