Testing the efficacy of a fractionating column?

Is there an easy way to do it without an FTIR or similar to analyze your product? I'm actually a professional chemist working my first job in R&D at a plastics company but the place is brand spanking new and therefore is light on a lot of chemistry basics you'd find at an average lab (I had to buy RC car fuel and distill out the nitromethane when I needed methanol). Anyway, the glassware kit we bought had this addition funnel with ground glass joints top and bottom that I'd like to try and use for fractional distillation. I bought some 1cm glass beads at the craft store and used them to fill the column which I think will make for a good fractionating media. Of the non-chlorinated solvents we have available (ethyl acetate, IPA, THF, acetone and xylene) I think the best pairing for a test would be acetone/THF (BPs 10°C apart ). I have it handled up to that point, what I'm struggling with is how I can confirm the purity of my final product without the spectroscopy I took for granted back in undergrad.

This is my first post so if its in the wrong place, let me know.

Do you understand how to measure the boiling point of the components There's some useful information in the forum library if you don't The end results from the effort applied

Quote: Originally posted by leu

Do you understand how to measure the boiling point of the components There's some useful information in the forum library if you don't The end results from the effort applied

Quote: Originally posted by forgottenpassword

You might want to use something more efficient than 1cm glass beads! Most things would be more efficient. Even bread! Use thin layer chromatography to compare your isolated substance to a known sample. If the two substances behave identically on the same plate then there is a high probability that they are the same substance. If they behave identically on two different plates then they are certainly the same substance. Silica and alumina plates will allow you to categorically identify most substances, so long as you have reference standards, which I assume that you do. [Edited on 28-1-2014 by forgottenpassword]

This right here is what I was looking for. I somehow managed to forget that TLC was a thing. I don't have plates right now but they're quite a bit easier/faster to get than an FTIR

Whats ineffective about beads? I was planning on having the purchasing coordinator add some Raschig rings to the next order of lab equipment (which will now also include some silica gel plates), but in the meantime, can you recommend another material I should pack the column with?

Quote: Originally posted by The Ideal Gas Lawyer

[Whats ineffective about beads? I was planning on having the purchasing coordinator add some Raschig rings to the next order of lab equipment (which will now also include some silica gel plates), but in the meantime, can you recommend another material I should pack the column with?

Quote: Originally posted by forgottenpassword

My mistake. I thought that you were going to do column chromatography rather than a distillation. Beads are fine.

Quote: Originally posted by blogfast25

Quote: Originally posted by The Ideal Gas Lawyer   [Whats ineffective about beads? I was planning on having the purchasing coordinator add some Raschig rings to the next order of lab equipment (which will now also include some silica gel plates), but in the meantime, can you recommend another material I should pack the column with? The ratio of surface area to bulk volume for beads is lousy. The fact that they take up some much volume (for a given surface area) can lead to 'column flooding'. Raschig rings are much better. I think they probably represent the best cost/effectiveness ratio, compared to some more exotic column packings like saddle shapes. [Edited on 28-1-2014 by blogfast25]

Quote: Originally posted by The Ideal Gas Lawyer

That's my understanding as well. I think the glass should work OK while I wait out the requisition process though. Until the real rings come in, I wonder how well 1/4" stainless steel nuts would work, assuming I'm not trying to separate anything super corrosive.

Quote: Originally posted by Cheddite Cheese

It is an addition funnel. However, he intends to use it as a fractionating column. I think it's worth a try, but is unlikely to be as good as the real thing.

Quote: Originally posted by bfesser

Don't bother trying to use that addition funnel as a <a href="https://en.wikipedia.org/wiki/Fractionating_column" target="_blank">fractionating column</a> <img src="../scipics/_wiki.png" />. Just buy a real column off of eBay, or from a lab supplier&mdash;they're relatively cheap. There's too much of a constriction in the stopcock bore for your plan to be successful. Also, stainless steel, copper, and bronze scouring pads ('wool') should all be available at a local hardware store, and make great column packing.

Quote: Originally posted by Magpie

I agree. The bore on that stopcock plug is likely no more than 3mm. It will severely restrict your boilup rate.

Quote: Originally posted by Magpie

... Separating two liquids with a bp difference of only 10°C is going to be a challenge. My guess is that you will need a column of length no less than 600mm. You might also need a still head that will provide reflux control. ... What liquids do you intend to separate and what efficiency do you require? ....

Quote: Originally posted by Magpie

... The next time you need methanol, and don't want to order it from a chemical supply house, use gasoline de-icer "Heet" or "Drygas."

Quote: Originally posted by The Ideal Gas Lawyer

In that case I'll probably try an easier combination first. maybe IPA and THF (16°C) or Acetone/EA (21°C) I'm unfamiliar with the sort of still head you're talking about can you explain some more?