I decided to reproduce An1cca's extraction method with some deviations here and there. Here I share my progress.
I took several cuttings of T. Peruvianus, carefully dethorned them with a scalpel (remove as little skin as possible), cut in 5 mm stars, dried in a food dehydrator until cracker-dry, ground in a coffee grinder to a coarse powder.
I weighed 24 grams of the powder, which is nearly twice as used in An1cca's article.
I will use this amount since my Soxhlet also has larger volume than in the article (250 ml vs 150 ml).
I mixed the powder with 100 ml of basic alcohol (98 ml methanol, 2 ml ammonia 25%) as instructed - I may have used 200 ml instead since I have larger amount, but I realized this too late. The original method also uses ethanol, which has its pros and cons. I don't have enough high proof ethanol so I used methanol instead.
I placed the beaker in a hot water bath (60°C). I used pressure cooker as it has thick walls and the lid can be sealed for better insulation. After few hours, I re-heated the water bath to 60°C and left to sit overnight.
The next day, I decanted/filtered the liquid and loaded the plant material in a glass thimble. The liquid went in a 500 ml round bottom flask.
I added 250 ml of fresh methanol in the RBF, totaling 350 ml (the Soxhlet body has capacity of 250 ml so when the body is full, the bottom flask still has 100 ml of extract in it).
I ran the Soxhlet for several hours using heating mantle with stirrer. I cycled quickly and the liquid went from dark green to very light yellow/green tint:
I planned to flush the excess 250 ml of methanol, leaving 100 ml of concentrate in the RBF but after flushing some 230 ml, the flask seemed to contain very little liquid. I realized it has only 60 ml in it so the methanol must have either soaked in the plant matter or escaped:
I topped the amount of extract to 100 ml and continued according to tek. I added 400 ml of water containing 8 ml of 23% HCl to the flask with concentrated extract. Lots of solids have precipitated so I decided to filter it.
I used vaccum filtration adapter and filtered the liquid straing into 1 L round bottom flask.
Unlike in An1cca's notes, my precipite is dark green, not brown. This might be caused by the use of different solvent or shorter extraction maybe.
The acidic filtrate is brown, just like in the original tek:
And here is the RBF from Soxhlet. I think I concentrated the extract little too much, since it left precipitates on the walls:
I also realized I should have distilled the alcohol off first, then filter, so I proceeded to simple distillation. I found flat bottom flask is much more suitable to distill off the alcohol than the large RBF - it also has graduation so I can check I have distilled off 200 ml (this means most alcohol will be removed).
Next time I will use the Soxhlet to distill off the alcohol. It will save me from building the distillation apparatus and the thimble with exhausted material can be left in since we will need to purify the alcohol later anyway.
I was left with 285 ml of mostly aqueous extract:
I filtered it again using paper filter with a thin bed of Celite. This removed some black precipitate:
Now the extract is pretty clear:
I have prepared 50% NaOH solution and calculated how much to add to obtain 10% concentration of NaOH in the final solution:
(0.5x / (285+x)) = 0.1
The equation represents final concentration of 10%. The x in the left side is how much 50% NaOH is added. Solving for x gives us how much of the solution to add.
No reaction or clouding or clearing of the solution happenned, probably because I filtered it so thoroughly. Maybe I should have not filter it as it may have removed some goodies. Maybe it's better to filter after adding base. I don't know.
Anyway, I put the basic solution in the 1 L separatory funnel and extracted three times with 140 ml of toluene. The emulsion resolved easily in minutes, showing nice velvet beer effect after shaking:
I washed the separatory funnel with distilled water and then added 200 ml of fresh distilled water and pH indicator (0.4 ml of 0.2% nitrazine disulfide solution a.k.a. Nitrazine Yellow) as instructed in the original tek:
Then I added the combined toluene pulls and added 5% sulfuric acid in 0.1 ml steps. The indicator shows yellowing in the areas of high concentration of acid:
However, after shaking, the water turned violet blue again.
I continued adding the acid using a syringe until the water layer stayed yellow:
I then poured the water layer in a Pyrex dish for evaporation:
There was an interesting formation on the boundary of layers. I don't know what that is but I avoided pouring it into the dish:
After bathing the dish in hot water and with a fan turned on it, I decided to rather pour the water in a larger dish and place it on a heating mat. I already had success with this method.
Now let's go to sleep after 14 hours of hard work. I will continue later with weighing the extract and purification.