I'm a Beginner with a Capital B.
I did a soxhlet extraction using neutral grain vodka. With herbal medicine sometimes you want the synergy of specific ingredients. So some are soluable in water and others are soluable in alcohol. I'm definitely not in Ether league yet. I'm learning at home from reading and doing with my husband's loose guidance. I had to stop the extraction in the middle and refresh the solvent because it was getting saturated. I research stuff on the internet and using Dukes Phytochemistry and Mercks. I pick my solvent depending on a combination of information and experimentation and sometimes just intuition. Depends on what I want the herbal to do. I work full time so can't move nearly as fast as I'd like to - just setting up can take a lot of time.
California Poppy done this way is good for going to sleep and relaxing muscles that are overly tense.
Husband says Diatomaceous Earth is the Filter of Last Resort. It will work when nothing else will. (He worked a Summer for a big pool when he was a teen which is how he learned about it - has had a lonnnng term love affair with chemistry)
I wet it first because it is a breathing hazard and it makes a paste because the particles are very fine and powdery. I set up a 110 buchner with a #4 Whatman Filter and wet it down. Then I put about 1/3 inch layer of the diatomaceous earth paste on top. Then about an inch of wet sand - the diatomaceous earth will move around if you don't weigh it down somehow. I turned on a 90 torr vacuum and filtered 600 ml of extract through it twice. First time around was a bit cloudy still. The main reason I wanted the chlorphyll and other big particle stuff gone is it tends to cause problems when I'm evaporating off the alcohol. Much nicer extract without it.
We've experimented using it in sohxlet tubes with stuff that was really heavy and tending to clog with mixed results. If you just make a layer at the bottom of the soxhlet it tends to float up if you're working with a finely ground herb.
Wiki says: It is used in chemistry under the brand name Celatom or Celite as a filtration aid, to filter very fine particles that would otherwise pass through or clog filter paper.
From Leslies Pool Supply: "Many pool professionals consider Diatomaceous Earth filtration to be the finest. This material acts as a sieve removing smaller particles than sand or cartridge filter systems. D.E. is a porous powder with microscopic openings, that when magnified look like tiny sponges. Clear water can pass through these openings, but particles as small as one to three microns (average grain of sand is 1000 microns) are trapped in the media. The powder is usually poured into a slurry inside the skimmer and then it coats the filter grids."
"Diatomaceous Earth is a remarkable, all-natural product made from tiny fossilized water plants. Diatomaceous Earth is a naturally occurring siliceous sedimentary mineral compound from microscopic skeletal remains of unicellular algae-like plants called diatoms. These plants have been part of the earth's ecology since prehistoric times. DE is approximately 3% magnesium, 33% silicon, 19% calcium, 5% sodium, 2% iron and many other trace minerals such as titanium, boron, manganese, copper and zirconium. Diatomaceous Earth is a natural (not calcined or flux calcined) compound."
I'm extracting Ocimum tenuiflorum using a cold percolation right now and I put some of the diatomaceous earth paste in the bottom of the percolator to see if I can get a cleaner extract from the start. This is what the tube looks like - the white stuff in the bottom is the diatomaceous earth - I used a bit of coffe filter to keep it from coming out. You can see the edge where the liquid from the herb pack has started to soak into the white paste (tired of spelling it already!!) There is a food grade type that you can take internally, but the pool grade isn't recommended for internal use because of the high silica content.
It's also an insulator as someone pointed out, so it could be used as a sort of insulation bath if you wanted to try to keep something at a stable temperature.
The food grade is also sold as an insecticide for those of you into growing stuff. It tends to dry out critters that come into contact with it. Don't know all about that - is hard to keep it in place.
salat
