Comments on: Chemistry Lab Demonstrations: Candy Chromatography http://www.chemistry-blog.com/2009/04/10/chemistry-lab-demonstrations-candy-chromatography/ We have technical difficulties, it will take a day or two to get back to normal. Wed, 28 Jul 2010 17:51:43 -0700 http://wordpress.org/?v=2.9.2 hourly 1 By: Simon http://www.chemistry-blog.com/2009/04/10/chemistry-lab-demonstrations-candy-chromatography/comment-page-1/#comment-6599 Simon Wed, 02 Sep 2009 03:37:23 +0000 http://www.chemistry-blog.com/?p=1573#comment-6599 As long as it is not contaminated, it should work. I am not sure about the quality of your coffee though. I would think the lab filter is less porous than the regular coffee filter. As long as it is not contaminated, it should work. I am not sure about the quality of your coffee though. I would think the lab filter is less porous than the regular coffee filter.

]]> By: azmanam http://www.chemistry-blog.com/2009/04/10/chemistry-lab-demonstrations-candy-chromatography/comment-page-1/#comment-6510 azmanam Mon, 24 Aug 2009 11:22:14 +0000 http://www.chemistry-blog.com/?p=1573#comment-6510 yes, you may. In fact, good filter paper is thicker and sturdier than coffee filters. DIY chemists at home may not have access to lab filter paper though. yes, you may. In fact, good filter paper is thicker and sturdier than coffee filters. DIY chemists at home may not have access to lab filter paper though.

]]> By: al rey http://www.chemistry-blog.com/2009/04/10/chemistry-lab-demonstrations-candy-chromatography/comment-page-1/#comment-6509 al rey Mon, 24 Aug 2009 09:47:05 +0000 http://www.chemistry-blog.com/?p=1573#comment-6509 can i use a laboratory filter paper as my coffee filter. I think its cheaper to buy laboratory paper than that of pre-cut coffee filter paper. thanks alrey_ouano@yahoo.com can i use a laboratory filter paper as my coffee filter. I think its cheaper to buy laboratory paper than that of pre-cut coffee filter paper. thanks

alrey_ouano@yahoo.com

]]> By: azmanam http://www.chemistry-blog.com/2009/04/10/chemistry-lab-demonstrations-candy-chromatography/comment-page-1/#comment-5622 azmanam Thu, 28 May 2009 19:52:11 +0000 http://www.chemistry-blog.com/?p=1573#comment-5622 Glad you found it useful. I'm sure the authors did intend the setup to be "home chemist"-friendly. The stiffness of the filter paper definitely helped, so if you've got it, I'd use it :) Glad you found it useful. I’m sure the authors did intend the setup to be “home chemist”-friendly. The stiffness of the filter paper definitely helped, so if you’ve got it, I’d use it :)

]]> By: H. Lieber http://www.chemistry-blog.com/2009/04/10/chemistry-lab-demonstrations-candy-chromatography/comment-page-1/#comment-5620 H. Lieber Thu, 28 May 2009 17:36:10 +0000 http://www.chemistry-blog.com/?p=1573#comment-5620 Axmanam, Before reading your post, I had never heard of using candy for chromotraphy. I think it is a great idea. Thank you for clarifying how you had some glitches in the procedure, which seemed very helpful. Using wax paper and coffee filters did seem a little odd, but maybe the author decided to use materials you can find at home. I have always had good luck with filter paper and even paper towels work well sometimes. Another hint you might try is to fold/roll a piece of filter paper and stick into the center of the filter paper you have the dye on. Then place the rolled filter paper in the solvent. This allows only the rolled filter paper to get wet and helps prevent the dye filter paper to get soaked. Overall, thanks for the great procedure (I am planning on trying it sometime in my Chemistry class) and thanks for the great advice! Axmanam,
Before reading your post, I had never heard of using candy for chromotraphy. I think it is a great idea. Thank you for clarifying how you had some glitches in the procedure, which seemed very helpful. Using wax paper and coffee filters did seem a little odd, but maybe the author decided to use materials you can find at home. I have always had good luck with filter paper and even paper towels work well sometimes. Another hint you might try is to fold/roll a piece of filter paper and stick into the center of the filter paper you have the dye on. Then place the rolled filter paper in the solvent. This allows only the rolled filter paper to get wet and helps prevent the dye filter paper to get soaked. Overall, thanks for the great procedure (I am planning on trying it sometime in my Chemistry class) and thanks for the great advice!

]]> By: jon http://www.chemistry-blog.com/2009/04/10/chemistry-lab-demonstrations-candy-chromatography/comment-page-1/#comment-5129 jon Mon, 27 Apr 2009 05:48:37 +0000 http://www.chemistry-blog.com/?p=1573#comment-5129 Is it the caffeine in tea that fixes the silica plate, or will herbal teas also work? I would prefer to work with green or herbal tea. They're healthier. Thanks. Is it the caffeine in tea that fixes the silica plate, or will herbal teas also work? I would prefer to work with green or herbal tea. They’re healthier.

Thanks.

]]> By: sander http://www.chemistry-blog.com/2009/04/10/chemistry-lab-demonstrations-candy-chromatography/comment-page-1/#comment-5018 sander Wed, 15 Apr 2009 07:50:19 +0000 http://www.chemistry-blog.com/?p=1573#comment-5018 Ty, now I know I at least have a plan B when I see my compound decomposing on TLC. Ty, now I know I at least have a plan B when I see my compound decomposing on TLC.

]]> By: azmanam http://www.chemistry-blog.com/2009/04/10/chemistry-lab-demonstrations-candy-chromatography/comment-page-1/#comment-5014 azmanam Tue, 14 Apr 2009 11:43:24 +0000 http://www.chemistry-blog.com/?p=1573#comment-5014 This probably goes to answering your other question, below, too. Silica gel is acidic. In the presence of acid-labile groups, reactions can take place on silica. Silica gel is notorious for knocking off extremely acid-sensitive protecting groups on occasion. If this happens, you can deactivate the silica by doping the eluent with TEA. This will buffer the acidity of the silica gel and your acid-labile groups stand a better chance of surviving column chromatography. To do so, simply add ~3% TEA or so to your solvent mixture before you pack your column. This probably goes to answering your other question, below, too.

Silica gel is acidic. In the presence of acid-labile groups, reactions can take place on silica. Silica gel is notorious for knocking off extremely acid-sensitive protecting groups on occasion.

If this happens, you can deactivate the silica by doping the eluent with TEA. This will buffer the acidity of the silica gel and your acid-labile groups stand a better chance of surviving column chromatography.

To do so, simply add ~3% TEA or so to your solvent mixture before you pack your column.

]]> By: sander http://www.chemistry-blog.com/2009/04/10/chemistry-lab-demonstrations-candy-chromatography/comment-page-1/#comment-5012 sander Tue, 14 Apr 2009 10:53:07 +0000 http://www.chemistry-blog.com/?p=1573#comment-5012 How do you deactivate your silica with tea? And what are the effects? I've never done this before. How do you deactivate your silica with tea? And what are the effects? I’ve never done this before.

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