Polishing extracts
Some MMJ applications require greater purity and potency, so it is desirable to remove inactive ingredients like fats, lipids, and plant waxes, as well as any chlorophyll and other water solubles.
When I class chlorophyll with the water solubles, it is not in the same vein as the term is used in inorganic chemistry and is more involved. Chlorophyll itself has a polar head and hydrophobic tail, so it is mostly non soluble in polar water, but can be removed from the plant and conveyed by water as micelle.
Water also dissolves and washes away the Chlorophyll binding proteins and exposes the Chlorophyll to the solvent used. Chlorophyll is highly soluble in alcohol and slightly soluble in butane.
For further discussion of that subject, please see: Chlorophyll Pickup in Extractions | Skunk Pharm Research LLC
Processes that use a polar solvent and reflux or soxhlet to maximize extraction, also maximize and concentrate chlorophyll, which can be a problem for some people. The poison is in the dosage, so even for a salubrious ingredients like chlorophyll, some people can get too much of a good thing, producing digestive tract upsets, with attendant vomiting, cramps, and diarrhea.
See: Chlorophyll: MedlinePlus Medical Encyclopedia for details.
In a nutshell, many water soluble non cannabinoid ingredients come along for the ride when a polar solvent is used and water is present. While it is easier to use a process that minimizes their extraction in the first place, if that is a moot point, because you already have an extraction with excessive non-active ingredients, here are some ways to clean them up?
Filtering:
After re-dissolving the extract in ethanol or hexane, it may simply be filtered to remove the material that is insoluble. We usually use coffee filters for this purpose, or if we have a larger amount, we use a Whatman # 1 lab filter, with a vacuum assist.
If we wish to filter it further, we run it through 0.45 or 0.2 micron syringe filters, which takes out any remaining plant material, as well as any bacteria present.
Winterizing:
When using non polar solvents like butane and hexane, some non-polar waxes, fats, and lipids are extracted as well. An easy way to get rid of them is to simply re-dissolve the non-polar extraction in 190 proof (~95.5% azeotropic) polar ethanol and stick it in the freezer for about 48 hours at -18C/0F, for the waxes to coagulate.
The waxes will precipitate out of solution as the temperature drops and clump together so that they are easily filtered out with a standard coffee filter, or a Whatman #1 lab filter.
Here is what a winterizing filter cake looks like, while still wet.
After filtering, the alcohol is evaporated or vacuumed off, to leave a pristine Absolute.
Winterizing ISO, Methanol, and Denatured alcohol extractions:
Even though Ethanol is polar itself, it can still be used to remove some of the undesirables they pick up, because it is not as aggressive a solvent as Isopropyl and Methanol. By re-dissolving their extracts in hot ethanol and then placing that in the freezer overnight, some of the undesirables will precipitate out and may be filtered out.
Removing minor green coloration:
Because butane is non polar and considered insoluble in water, it is the longest chain alkane that is still slightly water soluble at 0.0325 vol/vol (3.25%). That means that a liter of n-butane will actually hold as much as 32.5 ml or mgs of water (1000ml X 0.0325).
3.25% by volume is also enough water to bring along some water solubles like chlorophyll and leave an otherwise pristine extraction with a green tint, usually light and sometimes a gorgeous electric hue.
These light green hues are easily removed without the more involved and extreme measures that I will follow up with, and is as simple as putting a jar of the oil suspended in an ethanol tincture, in sunlight or a light from a high UV source, like a grow lamp.
The UV radiation in the sunlight will quickly break down the chlorophyll and the breakdown products are amber, so the green color disappears.
Alas, UV radiation also destroys cannabinoids, but fortunately at a much slower rate, and three or four hours in the sun is usually enough.
Some MMJ applications require greater purity and potency, so it is desirable to remove inactive ingredients like fats, lipids, and plant waxes, as well as any chlorophyll and other water solubles.
When I class chlorophyll with the water solubles, it is not in the same vein as the term is used in inorganic chemistry and is more involved. Chlorophyll itself has a polar head and hydrophobic tail, so it is mostly non soluble in polar water, but can be removed from the plant and conveyed by water as micelle.
Water also dissolves and washes away the Chlorophyll binding proteins and exposes the Chlorophyll to the solvent used. Chlorophyll is highly soluble in alcohol and slightly soluble in butane.
For further discussion of that subject, please see: Chlorophyll Pickup in Extractions | Skunk Pharm Research LLC
Processes that use a polar solvent and reflux or soxhlet to maximize extraction, also maximize and concentrate chlorophyll, which can be a problem for some people. The poison is in the dosage, so even for a salubrious ingredients like chlorophyll, some people can get too much of a good thing, producing digestive tract upsets, with attendant vomiting, cramps, and diarrhea.
See: Chlorophyll: MedlinePlus Medical Encyclopedia for details.
In a nutshell, many water soluble non cannabinoid ingredients come along for the ride when a polar solvent is used and water is present. While it is easier to use a process that minimizes their extraction in the first place, if that is a moot point, because you already have an extraction with excessive non-active ingredients, here are some ways to clean them up?
Filtering:
After re-dissolving the extract in ethanol or hexane, it may simply be filtered to remove the material that is insoluble. We usually use coffee filters for this purpose, or if we have a larger amount, we use a Whatman # 1 lab filter, with a vacuum assist.
If we wish to filter it further, we run it through 0.45 or 0.2 micron syringe filters, which takes out any remaining plant material, as well as any bacteria present.
Winterizing:
When using non polar solvents like butane and hexane, some non-polar waxes, fats, and lipids are extracted as well. An easy way to get rid of them is to simply re-dissolve the non-polar extraction in 190 proof (~95.5% azeotropic) polar ethanol and stick it in the freezer for about 48 hours at -18C/0F, for the waxes to coagulate.
The waxes will precipitate out of solution as the temperature drops and clump together so that they are easily filtered out with a standard coffee filter, or a Whatman #1 lab filter.
Here is what a winterizing filter cake looks like, while still wet.
After filtering, the alcohol is evaporated or vacuumed off, to leave a pristine Absolute.
Winterizing ISO, Methanol, and Denatured alcohol extractions:
Even though Ethanol is polar itself, it can still be used to remove some of the undesirables they pick up, because it is not as aggressive a solvent as Isopropyl and Methanol. By re-dissolving their extracts in hot ethanol and then placing that in the freezer overnight, some of the undesirables will precipitate out and may be filtered out.
Removing minor green coloration:
Because butane is non polar and considered insoluble in water, it is the longest chain alkane that is still slightly water soluble at 0.0325 vol/vol (3.25%). That means that a liter of n-butane will actually hold as much as 32.5 ml or mgs of water (1000ml X 0.0325).
3.25% by volume is also enough water to bring along some water solubles like chlorophyll and leave an otherwise pristine extraction with a green tint, usually light and sometimes a gorgeous electric hue.
These light green hues are easily removed without the more involved and extreme measures that I will follow up with, and is as simple as putting a jar of the oil suspended in an ethanol tincture, in sunlight or a light from a high UV source, like a grow lamp.
The UV radiation in the sunlight will quickly break down the chlorophyll and the breakdown products are amber, so the green color disappears.
Alas, UV radiation also destroys cannabinoids, but fortunately at a much slower rate, and three or four hours in the sun is usually enough.
