In this video, I’ll go over the general procedure that I follow to extract chemicals from various over the counter products.
So you’ve decided you want to do an extraction but you don’t really know where to start it doesn’t really matter what you want to extract whether it’s lidocaine from the after sunburn lotion you see on the left or caffeine from the tablets on the right in general the process is going to be pretty similar the first thing to do is to look on the back and try to get
A list of all of the ingredients that are in it the ingredients of any given product is extremely variable so it’s very important that you choose something that has a list of ingredients on it if you have no idea what the ingredients are working blind is generally not an option for this video i’ll be extracting caffeine from the tablets as an example so the first
Thing you want to do is boot up excel or comparable program and start writing out all of the ingredients this should only take a few minutes and you’ll probably notice that there’s a lot of different chemicals inside the pill once i’m done writing out all the ingredients i make two more columns one labeled water and the other one labeled organic we’re interested
Here to see if the chemical is soluble in water or an organic solvent because this is going to be our major method of separation our first chemical on the list is erythrazine so we look up erythrazine msds to get the properties of it the msds won’t always show the solubility of it but it’s a good place to start luckily we see here that it’s soluble in methanol
And water so we go back to the excel sheet and under water we type yes and under organic solvents we type methanol with a little bit of further research we actually see that the erythrazine which is an fdnc dye is soluble in water but it’s really insoluble in organic solvents this is also helpful because knowing what each component is insoluble in will help us
Choose our extraction solvent we keep doing this until we have a final completed list of the solubilities of each component if possible it’s really useful to get the solubility of what you’re trying to extract in the various solvents this way you’ll know how much solvent to use for the extraction but this isn’t always possible if you can’t find the solubilities
You’re probably just going to have to use an excess of the solvent so next i highlight the completed table and i transfer it to a word document now we’re going to design our actual procedure the two options we have for a tablet is do we extract it first with water or do we extract it first with an organic solvent for organic solvent we’ll be using dcm and for
Each one i write down what they will extract from the pill so you see that if we wash it first with water and then extract that with dcm it offers no advantage over just flat out dissolving everything in dcm first in either case we’ll have pavidone and caffeine but if we start with water we’ll just have an added step so at this point we know that we’re able to
Isolate a mixture of povidone caffeine but how do we separate those well knowing that it’s possible to recrystallize caffeine from either alcohol or water we look at the list and we see that the pavidone is soluble in both alcohol and water so to deal with the pavidone we’ll just have to recrystallize the caffeine from either alcohol or water so from this point
We can start designing our extraction so we start off by crushing the tablets and then we dissolve everything into some dcm we filter off any of the solids we wash the dcm with some water to get rid of the water soluble stuff evaporate the dcm and then we can recrystallize our caffeine one important thing to note is that for any extraction there’s a huge array of
Different solvents and methods that can be used and this just happens to be the one that i came up with in the end designing an extraction takes just a little bit of problem solving and then applying the techniques and the solvents you have available to you as long as the procedure that you design yourself is not overly complicated and it’s relatively efficient i’d
Consider it a pretty good method anyway enough talk about procedure design and let’s see if it works just to be clear a full length video on this extraction will be posted later anyway first the tablets are crushed placed into an erlenmeyer and dcm is added on top it’s allowed to stir for a while so that all the caffeine dissolves afterwards it’s allowed to stand
So the solids settle to the bottom the upper more liquid portion is then filtered off i don’t show it here but the stuff at the bottom was washed a few times with dcm our dcm is then evaporated off the dcm is pink and kind of cloudy because some of the stuff made it through the filter and also i skipped the water washing steps because i plan to recrystallize from
Water eventually all the solvent is gone and we’re left with some solid we then recrystallize it from hot water filter it and dry it in an oven we’re then left at the end with some very nice white powdered caffeine with a yield of about 85 to 90 percent you’ll probably notice that the exact procedure that i took actually varied from the procedure that i planned
It’s important to know that when you actually do your extraction depending on what happens it’s probably going to vary from what you planned for example i plan to actually recrystallize from ethanol but halfway through i realized that i could just skip the washing steps if i recrystallized from water also some chemicals might behave in ways that surprise you and
You’re going to have to adapt as you go you also have cases like in the case of this lidocaine spray i have on the left where the extractions just fail when i planned it out it actually seemed it would be very easy but in practice it was really really annoying they included a surfactant which made the extractions really really prone to emulsions and also when i
Added bass some weird polymer precipitated out after trying a few times i just realized that it was a total failure and a waste of time and i had to find a different product to extract from if you look up lidocaine sprays and what they’re used for you might get an idea as to what i chose i have a feeling some people are going to laugh about what i ended up using
This is a list of all the videos that i’ve already filmed and a list of the videos that i plan to film in the future so if you’re interested in seeing any of these remember to subscribe and if you’re feeling generous donate to my patreon account because chemistry is pretty expensive anyway that’s all for now and i’ll see you next time
Transcribed from video
How to extract chemicals from over the counter products By NileRed
