D-glucose
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Limonene extraction
Hi all! Firstly, I would like to congratulate you on such a great forum! This is my first post so please don't be to harsh.
Recently, I embarked on a quest to extract Limonene from orange peels. I followed the procedure here; http://www.rsc.org/learn-chemistry/content/filerepository/CM... The only modifications I made were that i used a 100 ml RBF, an alcohol burner,
50ml of DW and a 50 ml graduated cylinder. Everything went fine, and i stopped the distillation after i had collected about 20 ml of water with a ml
of the less dense Limonene bobbing happily on top of the water- but i had one grief; I had no pipets!
So I cleaned up my apparatus and left the Limonene in the graduated cylinder overnight to settle. In the night I had found a pdf. that noted that
Limonene was soluble in acetone (pdf here http://monographs.iarc.fr/ENG/Monographs/vol73/mono73-16.pdf) So i went a head a poured the limonene + water into a small sep funnel and then
about 5ml of acetone, where a white milky solution occurred with the limonene on the top. At that point fearing i had created some sort of
toxic/carcinogenic compound, i quickly drained the bottom layer into a beaker, flipped the funnel "retrieved" my so called product and flushed the the
bottom layer into the drain with plenty of water and washed my apparatus.
I'm completely aware that i isolated orange oil with limonene in it along with other terpenes/compounds. Any ideas of what that could of
been? Did i overreact? should i be worried i unleashed some sort of terrible compound into the water system? I guess it's too late to worry but i
thought i would share my experience.
Edit: I'm now more or less aware of what i think happened.. the acetone separated the limonene from the orange oil. i forgot to mention that the
organic layer smelt like oranges but the aqueous did not. Also, that the organic layer was not as viscous any more and the total volume had
significantly decreased.
[Edited on 16-12-2012 by D-glucose]
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smaerd
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You did not create a terribly toxic compound. It's okay  . A little knowledge
and a little less fear brings forward a bit more certainty. One thing I don't really understand is this, if limonene is soluble in acetone, and
acetone is miscable with water why would you add it to try and clean up the limonene? If anything I would have suspected forming a one layer solution
if enough acetone was added. Either way it appears that you have done a successful steam distillation of the plant material.
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kristofvagyok
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| Quote: |
At that point fearing i had created some sort of toxic/carcinogenic compound, i quickly drained the bottom layer into a beaker, flipped the funnel
"retrieved" my so called product and flushed the the bottom layer into the drain with plenty of water and washed my apparatus.
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That's cute(:
Usually when working with natural substances and isolationg something from them you've never get pure product first time. An orange and every else
like that is a living form, in every cell it has millions of different chemicals, so if you start to distill it not just water and limonene will come
over, even if it smells like that(:
About the fear of generating highly carcinogen and dangerous stuff, always remember that you have started from orange what could be eaten in 100%, and
you have just added a solvent what usually doesn't changes anything chemically(:
P.S.: I have made long-long ago a limonene extraction similar to your, the only difference was that we've used a 5000cm3 RBF and 2kg of orange peel.
It is an easy and well working producere, with great results, so do it again, limonene is a great compound(:
I have a blog where I post my pictures from my work: http://labphoto.tumblr.com/
-Pictures from chemistry, check it out(:
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D-glucose
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I don't think it's cute >.< either way, i thought i had done something terrible! The reason i used acetone even though it is miscible in water
was, at the time, i thought it would be cool to try it out and that i had no other solvents to try. ( although i did not expect a milky solution but
it was probably the compounds in the orange oil soluble in the limonene being precipitated out?) Happy to report my results though, maybe others could
try and see what happens?
-glucose
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Hexavalent
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A few days ago I added fine orange peel (from one large orange) to ~50ml of acetone and magnetically stirred for 3 hours. I removed all the pith
first, and ripped the peel manually into small squares, perhaps 10mm x 10mm. The acetone was nail polish remover grade, distilled and dried.
I filtered the acetone solution, which was an orange/yellow colour, and transferred into a crystallizing dish. Over the past few days a very fine
yellow powder has settled out at the bottom which cannot be filtered with the lab filters I have (too fine). It does not smell of oranges, nor
anything for that matter.
Any suggestions as to what has happened?
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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kavu
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Quote: Originally posted by Hexavalent  |
I filtered the acetone solution, which was an orange/yellow colour, and transferred into a crystallizing dish. Over the past few days a very fine
yellow powder has settled out at the bottom which cannot be filtered with the lab filters I have (too fine). It does not smell of oranges, nor
anything for that matter.
Any suggestions as to what has happened? |
That would be the wax alongside with some oils and pigments.
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Hexavalent
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These are unwaxed oranges...
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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kristofvagyok
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Acetone is not a selective solvent...
Is it possible to recrystallize the powder what came out? Did you tried to add another solvent? Adding hexane usually participates out everything what
is not perfectly apolar and usually dissolves the waxes what ARE ALWAYS PRESENT IN NATURAL SUBSTANCES. Is the powder soluble in water? Did check a
TLC?
Also remember that an orange contains millions of chemicals, so the extraction with a good solvent as acetone will always end up with a mixture of a
lot things.
I have a blog where I post my pictures from my work: http://labphoto.tumblr.com/
-Pictures from chemistry, check it out(:
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D-glucose
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Here, read this; http://en.wikipedia.org/wiki/Orange_oil Kristof is right about it all being natural so i don't particularly care about the compounds being
poisonous. And my product is very mobile( like acetone ) and has beads of a clear substance ( limonene i presume ) which when i shake it a lot of
littles sphere of the "limonene" come out of solution and redissolve leaving some immiscible bubbles. my theory is due to the fact acetone is miscible
in the water it dissolves and the acetone is saturated with whatever compound i extracted and when you shake it they mix and the mystery compound
comes out of solution because of being in contact with the water and then they redissolve ( you get the point )
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Zephyr
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After spending 45 minutes tediously scraping the white inner membrane off the outer skin as called for in the procedure, I only left with one
question,was it necessary? Would it not simply be easier to distill a mixture of an entire orange?
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Metacelsus
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I think it would not terribly hurt your product to steam-distill the white part along with the orange part, because I believe the white part would not
have any low-boiling compounds that might contaminate your distillate (besides water, of course, but you're already adding that).
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manomanom
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I believe that orange oil is (at least 99%) limonene.... though i have been wrong before.
Who has lots of spare time, and loves pdfs??? This guy!! Here's some that might help:
Attachment: Limonene.pdf (355kB)
This file has been downloaded 675 times
Attachment: extracting limonene from oranges by steam distillation.pdf (685kB)
This file has been downloaded 1041 times
Attachment: limonene extraction from oranges.pdf (151kB)
This file has been downloaded 2860 times
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foxofax474
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Just as a note on the purity, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6222077/ here they did a gas chromotography analysis and found that the limonene extracted from steam
distillation is around 77.39-89.13% pure.
(See tables 2 and 3)
I'd imagine you could do repeated fractional vacuum distillations to achieve a higher purity.
[Edited on 22-3-2024 by foxofax474]
(∩^o^)⊃━☆ the proof is by magic
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