The common concept is that a solvent can be used just that many times, after which it becomes "saturated" and does not pull that efficiently. After this point one has to either distil the solvent to a (considerably) cleaner, reusable distillate or simply to discard the solvent somehow and/or evaporate it to collect whatever traces may be left behind. The distillation route is the most reasonable thing to do, but it is a technology to which the vast crushing majority of kitchen chemists do not invest to, for reasons of safety, time, money and what not. Since distillation cannot be widely recommended (on the contrary, it should be suggested to with caution!) there appears to be no much to do other than discarding overused solvents (i.e. the ones that do not evaporate easily like limonene, xylene, toluene, heavy naphthas) or just evaporating them (light naphthas, dcm, chloroform).
Both discarding and evaporating are wasteful processes that seem to be a "necessary evil" amidst lack of distillation apparatus and knowledge to distil safely, but does it need to be so? I will argue here that a solvent can be used a million times without its ability to pull freebases be compromised to any detectable degree. The spark for this thesis comes from a friend who was performing some extraction on mhrb with limonene that had been used to extract at least 500g of mhrb previously as well as roughly 1.3 kilos of cactus powder in a period of a couple of years. After repeated saltings with acidic water, this orangey limonene had been finally washed with salty water and stored till its recent use. Bottom of the line is that this guy's yield using this overused limonene was as expected and comparable to what he'd yielded from using fresh, virgin limonene. It is this apparent lack in efficiency loss between the fresh and the overused limonene that prompted me to re-think about solvents and make this post.
First off, I think that there are not enough (and not reliably enough) hard data regarding any diminishing ability of a used solvent to pull freebases. It all stems from empirical subjective observations and the apparent intuitive predisposition that "the more used a solvent is, the worse it will perform". But given the lack of hard data and measurements, we cannot really make such a conclusion. This is a serious gap but easily filled as people take on experimenting more with their extractions.
Second, what really happens to a solvent after many pulls? From clear transparent it goes to light yellow, then deeper yellow and so on, this coloration coming from plant fats, oils and other lipophilic substances. The more the solvent pulls, the more complex it becomes, but does it become saturated, let along a poorer solvent for freebased alkaloids? Saturated is a poor and misleading term since a solvent can be called saturated with respect to one solute, say dmt freebase or caproic acid or whatever. And does the term saturation apply in our case? Can one saturate olive oil with, say castor oil? Well, no since olive oil and castor oil are miscible in any proportions. Same goes for limonene and acetone. Can you saturate limonene with acetone? Again, not. The remark here is that an overused non-polar solvent just gets enriched with more fats and oils that do not exactly saturate the non-polar solvent used in the extraction, but they merely enrich it. To use other words, they make a complex solvent different from the starting one, e.g. one may state that in his extraction he used "a combination solvent of limonene and cactus fats and oils" to pull dmt. The question is: does this combination solvent perform better, worse or the same regarding its ability to pull the desired freebases compared to the clean solvent? Well, the answer can go either way, but from the incident extraction described above I am more inclined to believe that there is not much difference or in the worst case scenario, there is not going to be a negative impact serious enough that cannot be rectified by doing a couple extra pulls.
Third and last, people already use and report successful extractions of both cactus and mhrb using sunflower oil, canola oil, lard, dog fat etc. These oils are a freaking combination of painfully diverse plant fats and oils. In fact, these oils can be viewed as if one had taken an overused non-polar solvent, distilled off the solvent part then only used the residual oils for his next extraction. Or, it is as if one had used his non-polar solvent so any times that now the ratio of plant oils/fats to limonene is 100000000:1
So, end point thus far is that there is no much rationale on talking about overused, "weak" solvents. Hard data may indicate otherwise (after all, all my points are purely theoretical, stemming nevertheless from a single but convincing observation). Finally people should be encouraged to use the hell out of their solvents instead of throwing them away and if they feel that the yield is lacking behind, then they can do few extra pulls with fresh solvent and see for themselves if anything was really left behind. Any criticisms/discussion/refuting/questions on my points are greatly welcome,
Cheers,
Infun
Both discarding and evaporating are wasteful processes that seem to be a "necessary evil" amidst lack of distillation apparatus and knowledge to distil safely, but does it need to be so? I will argue here that a solvent can be used a million times without its ability to pull freebases be compromised to any detectable degree. The spark for this thesis comes from a friend who was performing some extraction on mhrb with limonene that had been used to extract at least 500g of mhrb previously as well as roughly 1.3 kilos of cactus powder in a period of a couple of years. After repeated saltings with acidic water, this orangey limonene had been finally washed with salty water and stored till its recent use. Bottom of the line is that this guy's yield using this overused limonene was as expected and comparable to what he'd yielded from using fresh, virgin limonene. It is this apparent lack in efficiency loss between the fresh and the overused limonene that prompted me to re-think about solvents and make this post.
First off, I think that there are not enough (and not reliably enough) hard data regarding any diminishing ability of a used solvent to pull freebases. It all stems from empirical subjective observations and the apparent intuitive predisposition that "the more used a solvent is, the worse it will perform". But given the lack of hard data and measurements, we cannot really make such a conclusion. This is a serious gap but easily filled as people take on experimenting more with their extractions.
Second, what really happens to a solvent after many pulls? From clear transparent it goes to light yellow, then deeper yellow and so on, this coloration coming from plant fats, oils and other lipophilic substances. The more the solvent pulls, the more complex it becomes, but does it become saturated, let along a poorer solvent for freebased alkaloids? Saturated is a poor and misleading term since a solvent can be called saturated with respect to one solute, say dmt freebase or caproic acid or whatever. And does the term saturation apply in our case? Can one saturate olive oil with, say castor oil? Well, no since olive oil and castor oil are miscible in any proportions. Same goes for limonene and acetone. Can you saturate limonene with acetone? Again, not. The remark here is that an overused non-polar solvent just gets enriched with more fats and oils that do not exactly saturate the non-polar solvent used in the extraction, but they merely enrich it. To use other words, they make a complex solvent different from the starting one, e.g. one may state that in his extraction he used "a combination solvent of limonene and cactus fats and oils" to pull dmt. The question is: does this combination solvent perform better, worse or the same regarding its ability to pull the desired freebases compared to the clean solvent? Well, the answer can go either way, but from the incident extraction described above I am more inclined to believe that there is not much difference or in the worst case scenario, there is not going to be a negative impact serious enough that cannot be rectified by doing a couple extra pulls.
Third and last, people already use and report successful extractions of both cactus and mhrb using sunflower oil, canola oil, lard, dog fat etc. These oils are a freaking combination of painfully diverse plant fats and oils. In fact, these oils can be viewed as if one had taken an overused non-polar solvent, distilled off the solvent part then only used the residual oils for his next extraction. Or, it is as if one had used his non-polar solvent so any times that now the ratio of plant oils/fats to limonene is 100000000:1
So, end point thus far is that there is no much rationale on talking about overused, "weak" solvents. Hard data may indicate otherwise (after all, all my points are purely theoretical, stemming nevertheless from a single but convincing observation). Finally people should be encouraged to use the hell out of their solvents instead of throwing them away and if they feel that the yield is lacking behind, then they can do few extra pulls with fresh solvent and see for themselves if anything was really left behind. Any criticisms/discussion/refuting/questions on my points are greatly welcome,
Cheers,
Infun