ive searched for "menthol extraction" and came up with nothing, so please don't flame saying i didnt search.
i have learned that most species of mint are high in menthol and menthone, and looked at all the wild mint that is around (lemon balm is everywhere,
and the peppermint is hogging so much holler water, it's almost become an invasive species) and was interested to see if there was a way to put all
this mint to use.
i searched on google and here, with not a lot of headway. but would any of you be in the know on a effective amature house extraction of menthol?not_important - 30-5-2008 at 14:23
Mints generally yield about a half percent by weight of essential oil. Steam distillation is typically the first step for treating the essential
oils, after that the process depends on the species and target products.
In my area mint farming is big business and a couple of natural products types have a refinery where they re-distill the oil they get from farmers and
sell to Wrigleys... I've been looking into critical fluid methods but the barrier is solvent recovery .. so far too much energy needed. You can also
use solvent extraction. I designed an extractor that works at the boiling point of the solvent as opposed to the condensed material as in a Soxhlet.Sauron - 30-5-2008 at 23:38
See the book or books on essential oils in the forum library. They are really tricky to find because they have the title THE ESSENTIAL OILS. mean,
who would ever thing of looking in there?
Pure menthol is commercially available, as are the essential oils of mentha spicata, and other mint species. Those are mixtures and rather elaborate
techniques are required to seperate the components. I mean HPLC, spinning band columns, that sort of thing. So depending on your application, you may
be better off with purchasing.
Or you may want to investigate synthesis, unless the optical activity is important to your application. Even then, resolution of a racemate may be
somewhat easier than isolation of pure menthol from the essential oils.Nicodem - 31-5-2008 at 02:38
I don't think the isolation of menthol from the mint essential oil is easy enough for the average amateur chemist. You should check the patent
literature. Also the book Sauron told you to read, generally also describes the typical isolation procedures with references. So that should be the
first source you should have checked before posting!
If the menthol content of the mint essential oil in your area is particularly high you could attempt to crystallize it by diluting the oil with some
petroleum ether and put the solution in the freezer for a couple of days. If you are lucky enough the menthol with crystallize out and you can filter
it while still cold. Other alternatives probably require good distillation equipment like efficient distillation columns and a stable vacuum source.
Edit: Actually I was wrong. It appears it is easy to isolate menthol from mint oil even without a distillation column. A couple of recrystallizations
of mint oil gives essentially pure menthol. So, no equipment is needed (except of course a distillation still as used for brandy making in order to
steam distill the essential oil from a large enough amount of the herb).
[Edited on 31/5/2008 by Nicodem]chemrox - 5-6-2008 at 20:50
Right- the natural products guys are distilling for consistent product not menthol so the goal is different. I too would be after an oil rather than
pure menthol which is easy enough to obtain commercially. I want a lower energy method to pull the oil if possible but it's kind of a back burner
thing for me. Anyway, not_important is right, steam distillation is the millennia old method and probably for very good reasons.
[Edited on 5-6-2008 by chemrox]JohnWW - 6-6-2008 at 16:40
Quote:
Originally posted by SauronSee the book or books on essential oils in the forum library. They are really tricky to find because they have the
title THE ESSENTIAL OILS. mean, who would ever thing of looking in there?
There is a thread on books on essential oils in the References section, which gave several downloading links for ebooks on the subject. I could give
Glaudge the links to download them by U2U, I suppose.
[Edited on 8-6-08 by JohnWW]Sauron - 6-6-2008 at 17:18
That will of course require the thread author to obtain password for References from a moderator.
