SOLVENTS
Solvents generally fall into two main
categories, Polar and Non Polar. Water is a highly polar solvent while oil is a
non polar solvent. As water and oil don't mix, neither do polar and non polar
solvents. Some other solvent properties that we are interested in are: boiling
points, specific gravity, toxicity, and selectivity. Selectivity is the
ability of a solvent to dissolve what we want and leave every thing else. For
example if we wanted to separate a mixture of salt and sand, water would be a
highly selective solvent. If we wanted to separate salt and sugar on the other
hand, water would be very non selective and basically useless. The early Salvia
extractions were performed using Chloroform (Ortega, et al. 1982) and Petroleum
Ether (Valdés, et al. 1984). Both of these are standard laboratory solvents for
organic extractions but if we use more selective solvents, we will increase the
purity of the final product.
Luckily, people have done experiments to
determine the selectivity of a few solvents for Salvinorin A extraction. The
following selectivity data was compiled by 'Divin0rum' of the Yahoo Salvia
group:
|
Total Weight mg |
Salvinorin mg |
Ratio (%) |
Solvent Efficency (%) |
| Acetonitrile |
.6 |
.12 |
20 |
47 |
| Isopropanol 91% |
4 |
.18 |
4.5 |
71 |
| Acetone |
2.7 |
.19 |
7 |
75 |
| Ethyl Acetate |
2.8 |
.13 |
4.6 |
51 |
| Dichloromethane |
3.3 |
.16 |
4.8 |
63 |
Details
As
you can see, acetonitrile is a fairly selective solvent for Salvinorin A.
Unfortunately, it is also hard to find locally and is pretty poisonous (it is
also known as Methyl Cyanide).
Our next choice would be Acetone. Acetone
is very easy to get from any hardware or paint store and not extremely toxic
since it is also used as nail polish remover (you should avoid skin contact,
long term exposure or high concentrations of vapors). Try to get an MSDS for any
solvent you will be working with. Acetone produced for commercial purposes is
fairly pure but DOES contain contaminates. Before being used for 'pharmcutical'
extractions, it should be purified by Distillation. An
alternative would be to buy reagent grade acetone from a chemical supply
company. It is known that acetone, petroleum ether, and chloroform are among
many 'watched' chemicals; the DEA requests (requires?) that chemical companies
report suspicious orders to track down illegal drug labs. If you were to order a
55 gal drum of a watched solvent to a residential address, the DEA would
probably be lurking around your house fairly quickly. If you just ordered a
quart or two???? I doubt anything would happen but to be safe, you should have
it shipped to a different place than you plan to use it.
Many solvents
have legitimate household uses and are sold under familiar brand names. As
mentioned above, they should be distilled first. To test the product for
contaminates, you can do an evaporation test a/k/a a residue test. In order to
get accurate results, a fair amount of product should be evaporated (not just a
couple of drops). Ideally, you should use the same amount of solvent you plan to
use in your extractions. To do the test, put some of the product in a clear,
VERY clean pyrex glass dish. Put the dish outside with a piece of screen or
something else to keep out debris while still letting air flow. You can speed up
the evaporation by putting the dish in a pan with some hot water and adding
water as it cools off. A fan blowing over the top will help too. The last bit of
liquid will probably not evaporate easily; as the final traces of solvent
evaporate, whats left is usually water. It can either be already in the product
or it may be absorbed out of the air. When only water is left, it will be cloudy
if there are water insoluble impurities. The impurities precipitate out as the
concentration of solvent goes down and you see this as 'milky' water. Put the
dish in a warm oven for an hour and it should be dry; if it still has some
liquid, the product contains heavy oils. If all the contents have evaporated,
look at the bottom of the dish. Is it still clean??? Does it smell funny??? If
the answer to either is 'yes' then you *should* be distilling it first. Try the
test with some 91% isopropyl alcohol from the drug store and it should come out
clean.
The Solvent
Reports contain information on sources of solvents from household items.
Some is from the net, some I have tested and found residues, others are just
unsuitable. As I test new products or find additional info, I will add them to
the reports.