So I decided to do this LL extraction today. I noticed my extract turning much darker after distilling off the etoh and adding 250ml of methanol (99.9%) to 80ml of extract and loading into the sep funnel. I then added 200ml of pentane and saw zero separation. I then added 25ml of distilled water and saw 3 distinct layers form, with the milky layer in the middle (didn’t get a pic). I agitated the sep funnel and the milky layer disapeared, with a much darker layer forming on top (pentane) and a much more transparent layer forming on bottom (aqueous layer). I expected the opposite to happen, didn’t expect milky layer to disappear, and now I’m wondering which layer my target compound is in and what the black junk is in the organic layer. I was originally doing this to remove all water solubles, but if I can actually improve the color and clarity of my extract with this method that would be fantastic.
the cannabinoids will be in the pentane layer predominatly, try adding an additional small amount of disilled h20 to force out any additional cannabinoids.
Have you played with washing against saturated salt water?
Thanks! I’ll do that now. And no, I haven’t. What does the salt do? Almost everything I have read about brine washes has been pertaining to pesticide removal.
you can read about how it works here.
Fuckin love you guys. Thank you so much. I also found this while browsing just now, for anyone who stumbles upon this thread and wants more info. Idk how I missed it before.
looks speorated, do a few more rinses.
So I was super pessimistic about my outcome, but I guess in a slab it’s not going to look half bad for my first run over 10g without a rotovap or vacuum oven. Thanks to everyone for your help, you guys rock. Any suggestions for future batches would be greatly appreciated. Pretty sure I just got impatient and cranked too much heat for solvent recovery. My small practice batches came out much better.
that looks good, nice work!
Tried and true method, and you don’t even need a separatory funnel. For small amounts, just use a pipette and pipette pump to carefully pull off the top pentane (or hexane, or heptane) layer containing the cannabinoids.
The petroleum ether referred to is a low boiling point faction, about 30-60C, containing mostly pentane with some hexane, use pure pentane if you can, or heptane is readily available, but it’s higher boiling point makes it harder to purge. Hexane is more toxic than pentane or heptane according to the FDA’s residual solvent guide:
From Cannabis Alchemy by D Gold:
Step 6: Purification
Oil produced using this method is quite potent, but still contains substances which give the oil its taste, smell, and color. These are sometimes very pleasant to smoke, and they are sometimes left in the oil. Removing them, however, greatly increases the potency, but decreases the yield proportionally.
The oil from the extraction is dissolved in five times its weight of alcohol and poured into an equal volume of water in a large glass jug with a screw-on cap. All solvents used are cold or cool. A volume of petroleum ether equal to half the volume of the water used is added. The screw top is tightened and the jug is inverted. The jug is turned upright immediately, and a few seconds later, when the mixture has run down the sides of the jug, the screw cap is opened slowly to relieve the pressure. The inversion of the jug is repeated about twenty-five times, which releases the pressure each time, and then the jug is allowed to sit for about half an hour. The mixture of liquids will separate into three distinct layers. The bottom layer will contain water, alcohol, and the substances in the oil (tars and resins) that are not soluble in petroleum ether. The thin middle layer is an emulsion of waxes, ether, and air bubbles. The top layer is the purified oil dissolved in petroleum ether.
The jug is fitted with a two-holed rubber stopper, glass tubing, and rubber hose. Two pieces of glass tubing are fitted into the two-holed rubber stopper. (Injuries when cutting and fitting glass tubing are frequent—cut ends are always fire-polished and hands must be protected when any force is used in fitting the tubing.) One piece of tubing need only protrude from the stopper an inch on each side. The other tube is positioned so that when the stopper is tightly fitted to the jug, the tube extends into the mixture to a half-inch from the bottom of the ether/oil layer. The other end of the tube is attached to a length of rubber tubing to transfer the ether/oil solution to a collection jug. The end of the tubing must be lower than the end of the tube in the ether/oil solution in order to obtain a siphon action. A short piece of rubber tubing is fitted to the short glass tube, and air pressure is applied to start the siphon.
The glass tube is spaced a bit above the emulsion layer; any ether/oil solution not removed will be recovered later. The ether/oil solution in the collection jug is saved. Another volume of fresh petroleum ether is added to the extraction by inverting, separating, and collecting the ether solution, which is added to the first ether/oil solution. This process is repeated until the ether layer remains clear after inverting. This indicates that the ether-soluble oil is totally extracted from the alcohol-and-water layer.
Here’s a link to where you can read this for free,
I recently took someone through this process, and he reported back complete satisfaction, though now he just extracts from the get go with pentane.
Pentane is a great solvent. I wish I knew about it years ago
So the cannabinoids are in the pentane layer??? I would think they are in the methanol layer since methanol has the highest affinity for cannabinoids.
Thank you very much @SkyHighLer Great write up!
@coppertop you’ve come a long way, great work dude
Haha, no kidding. Thanks man, I appreciate that.
Bioslacker - as you add water, the methanol preferentially wants to be in the water phase, and it leaves the cannabinoids in the alkane (at neutral pH). It is discussed in a number of different postings on the site. Good luck.