Sciencemadness Discussion Board

Seperation of Alpha, Beta Pinene from Turpentine

terpenedistillation - 8-11-2012 at 17:58

Hi, I have searched for similar threads to no avail, if this is a redundant topic I will cease activity herein.

Per title, I am interested in the isolation of Alpha and beta Pinene from turpentine.
It appears that I can easily fractionally distill off the Alpha and Pinene portion, but that it will contain varying amounts of Camphene. (http://www.chem.agilent.com/cag/cabu/pdf/turpentine.pdf)

Accordingly problem A: What methods can I employ to separate out this compound ? (Assuming, a fractional distillation will not give resolution)

Once I have the pinene fraction I am planning on using an entrainer of diethylene glycol to separate out the alpha and beta portions to considerable purity. Then hopefully taking beta portion to geraniol, nerol, and linalool, as well as moving the alpha-pinene through a couple steps.

Help very much appreciated, not sure if this can be done easily not on the industrial scale.

*ooh this is embarrassing, EDIT sorry, would a MOD be so kind so as to move this thread to the Biochem forum , I have been visiting this websites Orgo forum exclusively for months, and have noticed the emphasis on synthesis, but didn't realize NPC was entailed by the 'biochem' subforum, and although my reaction is synthetic my issue is one of NPC technique.

[Edited on 9-11-2012 by terpenedistillation]

terpenedistillation - 9-11-2012 at 18:30

I know i can run a column, but i'm young and silica gel is kind of expensive for a hobby. I also realize i could prep tlc on a small scale (and i suppose i could make the silica paste to put on the glass but, as well as making a decent column pack-but i have done both of these and want to have to learn a new technique (i've never used an entrainer before))

I am thinking of just pulling over the pinene class terpenes, then hoping that the diethylene glycol gives the camphene a distinct bp, so it can be fractionated out in the same pull a alpha and beta. Thanks for looking.

Nicodem - 10-11-2012 at 03:26

Have you truly thoroughly checked the literature? Given the industrial importance of the pinenes, I'm quite skeptical on how you presented your problem. It makes me somewhat reluctant to check Kirk-Othmer or the patent literature on how the pinenes are separated industrially, until I see some more effort from your side. Particularly, on the separation proposals you mentioned, I can hardly give an opinion, because they are not referenced.

You mention column chromatography which means you actually need just a couple of grams amounts. Why don't you just buy the two pinenes? They are very cheap - or you just want to do it for the sake of doing it? Also, what is the reference claiming pinenes can be separated on silicagel using column chromatography? I'm surprised that this could be possible, so I would like to see the article where you read about it.

terpenedistillation - 10-11-2012 at 14:08

Hi, Nicoderm; I am inbetween university's at the moment, and do not have access to much literature. I have searched on a couple of websites where they will let you read for free, but for some reason to no avail (google scholar also no avail).-I have been thinking about going to a local college library and making use of their access and printers but, well i tend to avoid people.
I was able to find a somewhat recent patent: http://www.google.com/patents/US3987121 regarding the entrainer selection, and more paper and pamphlets mentioning the synthesis, but for some reason (assuredly my looking in the wrong areas) I havn't been able to find alternative methods of separation. -I actually figured somebody who use to (or still does) work in industry is a member and could mention a method real quickly that i could continue to research.

Column, no i'm just bored and crazy enough to wash the column, reclaim my solvent and keep doing it.... I would like a chunk, i like to collect scents.-however i meant to imply i didn't want to use columns for logistics as well as price.
-Yes i want to do it for the sake of doing it! I am botany student with a strong emphasis on chemical signalling, and well natural product chemistry is my hobby, so it's kinda like my Friday night fun. Also it makes the biosynthetic pathways more concrete for me...

Yes yes the column! at the school i'm leaving i was a GC/MS driver for some of our organic chem professors, and was also the caretaker of the sustainable natural product gardens, but i never had to separate out the terpenes/polyols or anything for synthesis, it's just that well, its cold and i only have a little bit more plant material in my freezer to process and before i need to find new amusement (After this my eyes are on the rose ketone from carotenoid synthesis).
Oh i know from hundreds of review papers, and talks that colum with different phase packs can be used, (and unfortunately ((in literature)) they all pretty much just use that or HPLC to get the pinene resolution :( )

but: cdn.intechopen.com/pdfs/32738/InTech-Column_chromatography_for_terpenoids_and_flavonoids.pdf PAGE 14, mentions the different solid phases, so you don't have to believe a rando with 3 posts.

Don't worry about getting on kirk-othmer, if it's not an intellectually stimulating issue for you, why would you bother?
If i keep waiting to no avail i'll run the entrainer and send samples off to some friends to run a semi quantitaive on and see how it's looking.

thanks for looking. :) Hope to talk again soon.

Nicodem - 11-11-2012 at 03:16

Quote: Originally posted by terpenedistillation  
Hi, Nicoderm; I am inbetween university's at the moment, and do not have access to much literature.

It's Nicodem, not Nicoderm. You can find instructions on how to do literature work in the forum guidelines (link in my signature) which I recommend to you. For industrial processes, especially when it comes to separation from natural products, the first choice to look for, are the classical industrial chemistry encyclopaedias (Ullmann's, Kirk-Öthmer's, RÖMPP, Thorpe's etc.). If you check Kirk-Öthmer, you will see that alpha- and beta-pinene are isolated by fractional distillation (the chapter on terpenoids is attached). Obviously, the efficiency will depend on how good your distillation column is, how many times you redistil, and on your fractionation skills. Completely removing camphene is a challenge indeed and you should focus your literature work on that.
Quote:
Column, no i'm just bored and crazy enough to wash the column, reclaim my solvent and keep doing it....

...

Oh i know from hundreds of review papers, and talks that colum with different phase packs can be used, (and unfortunately ((in literature)) they all pretty much just use that or HPLC to get the pinene resolution :( )

but: cdn.intechopen.com/pdfs/32738/InTech-Column_chromatography_for_terpenoids_and_flavonoids.pdf PAGE 14, mentions the different solid phases, so you don't have to believe a rando with 3 posts.

You are confusing the scope of analytical and preparative chromatography techniques. While alpha-pinene and beta-pinene easily separate on GC, and perhaps with a proper method also on HPLC, ordinary preparative techniques have resolutions many orders bellow that of analytical ones. You are also inappropriately generalizing terpenoids by using general statements from that document. The difference between the alpha- and beta-isomers is in the position of the double bond while there is no polar anchor anywhere that would cause a distinctive behaviour on silicagel vs. mobile phase partitioning. Stationary phase which can interact with double bonds could potentially quite easily distinguish them. Indeed, the relevant statement from that document is: "Silver nitrate impregnated silica gel is also provide separation of terpenoids containing unsaturation (Bhat, 2005; Sarker et al., 2006)." The given reference should be checked to see how appropriate such a stationary phase is for isomers of pinene.
Quote:
Don't worry about getting on kirk-othmer, if it's not an intellectually stimulating issue for you, why would you bother?

I find the topic interesting for the amateur chemistry community, because turpentine is easily available and separating it into its constituents certainly is a worthy task for the average amateur. Though, the major constituents, such as the pinenes and camphene are very cheap to simply buy, the separation itself is an excellent practice in separation techniques.

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chemrox - 11-11-2012 at 11:16

Quote:
I find the topic interesting for the amateur chemistry community, because turpentine is easily available and separating it into its constituents certainly is a worthy task for the average amateur. Though, the major constituents, such as the pinenes and camphene are very cheap to simply buy, the separation itself is an excellent practice in separation techniques.


In other words it's damned good practice for when you want to separate something that took weeks and a succession of reactions using expensive precursors to make. I heartily agree. I'm going to get some "lamp oil" and start separating components. It will be an excellent exercise for getting my vacuum distillation setup working and if the trap doesn't exactly work as it should.. no big penalty just change the oil.

terpenedistillation - 11-11-2012 at 16:08

You are entirely correct, i did underestimate the amount of time that i would have to dedicate to a column separation, and should have factored in polarity (or lack thereof).

Sorry i wasn't clear i didn't mean to imply that i thought prep and analytical were the same, i meant to imply that all of the authors just jump from distillation to analytical in most cases, Or they run columns at a budget and for a length not replicable by a hobbyist.

In the patents, and a couple thesis i read the authors stated that simple fractional was nearly useless-i guess i shouldn't have trusted folk trying to sell something so much

thanks for the direction, your awesome. I wont come back until i have good news. i have only 40cm vigreux but will get to work, send results to friends and try and get em to run samples quickly. thanks again for putting up with me:)