Sciencemadness Discussion Board

Some questions on cloves extraction and white crystals

Little_Ghost_again - 22-9-2014 at 12:46

Hi
I am going to do a Soxhlet extraction with whole cloves and IPA, and a steam extraction on whole cloves. I want to compare the differences etc of the two methods.


My question isnt actually in the extraction, this I can UTFSE. My question is about a strange observation I made.

I wanted to see if IPA would leach the colour as well as the oil etc, I also wanted to get a rough idea if I was going to have to crush the cloves or if I could get decent results without (I have an allergy to cloves so prefer not to mess with the powder).
I placed 12 whole cloves in a small ramekin and covered to 3cm over the top of the cloves with IPA.
Now I now clove oil is volatile and so is IPA, but normally I can leave a beaker of IPA out most the day and the evaporation loss isnt much (room normally held between 12-15C).
I left the ramekin uncovered and went back 3 hours later. What I am left with is very very soft clove stalks, a slight brown/red tinge stain and some small white crystals!
Everything is absolutely bone dry, no oil of liquid at all.
Does anyone have a clue what the white crystals might be? I have evaporated oil of cloves before but all I got was a small amount of brown powder (more of a stain than powder).
I will try and get a picture if it helps. I am due to do the actual extractions in the next couple of days, I need to sort a different condenser to the one I was going to use, as I found out the water coil inside was plastic!
I have others but this one fitted the Soxhlet I wanted to use.

Metacelsus - 22-9-2014 at 17:38

When I extracted cloves (this was with supercritical CO2 in a chemistry class I took), I ground them up first. I'm not sure if an extraction would work with whole cloves. I doubt the solvent would diffuse far enough into the cloves to dissolve all the soluble compounds.

For the same class, I also did a steam distillation of (also ground) cloves. The conclusion was that steam distillation gave lower yields but higher purity (of eugenol+acetyleugenol, by NMR) than the CO2 extraction, because the extraction also gets non-volatile, high molecular weight compounds. I might be able to find the exact numbers somewhere.

I have no idea about the crystals. Maybe they are an air oxidation product of the oil; eugenol and acetyleugenol are liquids.

[Edited on 23-9-2014 by Cheddite Cheese]

Little_Ghost_again - 23-9-2014 at 00:16

Quote: Originally posted by Cheddite Cheese  
When I extracted cloves (this was with supercritical CO2 in a chemistry class I took), I ground them up first. I'm not sure if an extraction would work with whole cloves. I doubt the solvent would diffuse far enough into the cloves to dissolve all the soluble compounds.

For the same class, I also did a steam distillation of (also ground) cloves. The conclusion was that steam distillation gave lower yields but higher purity (of eugenol+acetyleugenol, by NMR) than the CO2 extraction, because the extraction also gets non-volatile, high molecular weight compounds. I might be able to find the exact numbers somewhere.

I have no idea about the crystals. Maybe they are an air oxidation product of the oil; eugenol and acetyleugenol are liquids.

[Edited on 23-9-2014 by Cheddite Cheese]


I didnt heat anything or doing anything, so I was wondering if IPA gave crystals if it was totally evaporated off? I am gong to take a look at them under the scope and see what kind of shape etc. There is no smell remotely like cloves or even IPA, seeing as a few on here have done this extraction etc I just thought someone might have come across crystal either from IPA or cloves.
The better way to have asked is does IPA give crystals if evaporated right down to nothing.
Thanks for the info. I would love to do a super critical on tomato plants! I read something last week about someone using butane to extract from a green illegal drug! I can see how to do it with CO2 and tomatoes but without all the kit I cant see anyway to recover the CO2.
I would need a ball mill or something to grind them, I dont want to inhale any of the dust! I react to oil of cloves, not in a serious way I just come out n a rash all over that itches for days!

hyfalcon - 23-9-2014 at 14:45

Residual peroxides in the IPA maybe?

Little_Ghost_again - 24-9-2014 at 02:33

Quote: Originally posted by hyfalcon  
Residual peroxides in the IPA maybe?

Maybe.........And I assume this is bad, I have seen warning about this on here but nothing that explains what peroxides are,how they are formed and in what way they are dangerous. So one the one hand maybe I should be running around in circles screaming for help, but on the other I would prefer to know why i am running around screaming for help :D.
So can someone put me out of my misery and explain these dreaded peroxides, or suggest a place I can visit for information :D
many thanks