Sciencemadness Discussion Board

Chromatography jars

thesmug - 10-3-2014 at 15:10

I was looking online for easier methods of doing chromatography since right now I use tall beakers with a pencil and a piece of string and I was always considering actual chromatography jars but they cost over $1000! Why are they so expensive and is there any place to get them where they aren't so expensive?

Hockeydemon - 11-3-2014 at 01:16

If you're referring to the chromatography jar that's listed on amazon it has to be a mistake. There is really no reason for you to even bother buying a chromatography jar anyways. Any jar will work just fine. If you need something more precise invest in a different technique. You're not going to gain any noticeable precision by buying a jar designed for chromatography.

I am curious what you mean when you say you're using a pencil and a piece of string though.

BTW Dr.Bob sells chromatography chambers for $20 on here.

[Edited on 11-3-2014 by Hockeydemon]

J2xP - 11-3-2014 at 04:34

Hockeydemon is right...there is no magic to regular jars vs. chromatography jars. The price is due to manufacturers capitalizing on the fact that is a "speciality item" so they mark it up insanely. I have chromatography jars (square and cylindrical) for sale cheap but as previously stated any jar will yield the same results.

Dr.Bob - 11-3-2014 at 09:42

I agree with everyone here. The only special thing about chromatography jars is a flat bottom is best and an easy way to close it, preferable without threads, as often plates sometimes move around when you try to take off the lid. I often use a simple tall crystallizing disk type jar (straight sides and flat bottom) and then put an upside down lid on the top, just to keep the solvent from evaporating. But simple TLC jars are $10 or so, depending on the TLC slide size. I do find a piece of filter paper on the bottom helps to keep the slide from moving around.

thesmug - 12-3-2014 at 14:25

Quote: Originally posted by Hockeydemon  

I am curious what you mean when you say you're using a pencil and a piece of string though.
[Edited on 11-3-2014 by Hockeydemon]

I lay a pencil across the top of the beaker, thread a string through the chromatography paper and tie the string around the pencil. The reason I wanted an actual chromatography jar is that I've seen them that have a glass bar across the inside that you can suspend the chromatography paper from.

Dr.Bob - 12-3-2014 at 17:04

So you are doing paper chromatography, I guess. You could form the piece of paper into a curl, then stand it on end as well. The key is to cover the container to keep the solvent from evaporating off of the plate or paper, as the normally improves the chromatography.

thesmug - 13-3-2014 at 22:04

Quote: Originally posted by Dr.Bob  
So you are doing paper chromatography, I guess. You could form the piece of paper into a curl, then stand it on end as well. The key is to cover the container to keep the solvent from evaporating off of the plate or paper, as the normally improves the chromatography.

I've thought of that but my chromatography paper comes in rolls of strips, each 2cm wide. Sitting them on their side would make for a very quick chromatography session!