ClearLight (Hive Addict)
10-04-02 18:37
No 364232
      Soxhlet for defatting  Bookmark   

  I wanted to know if anyone had any experience or input on using a soxhlet, say with trichloroethane, in the preliminary defatting stage of plant materials.

   Seems that this would be a good way to save solvent and would get the job done.  Given that alkaloids are usually (as I understand it) lightly bound in the material, would there be any loss doing so? 

Infinite Radiant Light - THKRA
(Hive Addict)
10-04-02 19:40
No 364248
      hopefully, I understand your question proper  Bookmark   

  I dont think you would want to defat until you have your acidic extract first.  However, if a large amount of plant material is to bee used, a soxhlet would bee excellent for doing a simple methanolic pull (which could then bee vapped resulting in a tar).
  Either way, your gonna want to make sure the crap is in acidic conditions first before defatting.
  Wouldnt want to throw away the tub with the washwater!
  It seems to me that it would bee most efficient to remove the bulk/roughage first, THEN defat.  Trying to defat whole plant matter without removing alkaloids- think of all the tannins resin wax etc that is attached to the fibers, youd bee at it for weeks.

Grind the snot out of it (really important for higher yeilds), then multiple freeze/thaw to fracture the cell walls.  Then MeOH extract w/soxhlet (only reccomended if going large scale) then vap the MeOH. Acidify, filter, filter, filter, defat etc...

Histrionic:      High
Narcissistic:     High
(Old P2P Cook)
10-04-02 19:46
No 364249
      Chlorinated solvent, too aggressive.  Bookmark   

I think that a solvent such as trichloroethane would likely take away some or a lot of the desired materials. If you wanted to try to defat this way then you should use petroleum ether.

Soxhlets are just OK, IMHO. I find that they are more trouble than they are worth.

Baseline Does Not Exist.
(Hive Bee)
10-04-02 22:27
No 364285
      Light hydrocarbons  Bookmark   

like pet ether, already mentioned by terbium, or pentane or hexane are the solvents generally used in defatting plant materials. After defatting, the pet ether is usually shaken with with weak acid (1-2 % hydrochloric or sulfuric acids, depending on the alcaloid to be extracted) in a sep funnel to get the small amount of also extracted alcaloid back. cool
But if you acidify your plant material before defatting, it should be possible to extract with dichloromethane, chloroform etc.. Adsorptive effects aside, all depends on the solubility of the salt formed from alcaloid + the acid you have the defatting agent you have take a wise choose...wink

Quidquid agis, prudenter agas et respice finem!
(Hive Addict)
10-05-02 04:35
No 364392
      re: Halogenated HC's vs HC's  Bookmark   

Thanks!  the amine is weakly bound, so it is highly possible that the Cl ion in the halogenated solvents could rip it out... Since I have TLC gear now, I'll check and see if I need to do a acid extraction of the solvent...

  I like the Pet. Ether idea, although Ott did use chloroform to defat first before he extracted the buofotenine from the and. peregrina seeds, which are loaded with fats...

  So I'll try a bit with each one and report back. I've found some very interesting extraction protocols that I'm amassing for the great root bark extract opus... 

(With a nod to God as to the ghetto method, there is a faster lab spec way which I am determined to perfect)

Infinite Radiant Light - THKRA