I’ve been using the paper ph strips to check ph on my LLE washes and my distillate/heptane mixes to see where corrections need to be made. They’re cool I guess, but sometimes annoying.
But I have this super nice bluelab meter just collecting dust since I retired the grows. You think the probe is solvent resistant? Only thing I could find is that it will survive an ethanol wash.
I guess I could just drop it in some heptane and see what happens, was just wondering if anyone has some direct experience 
You should be testing the aqueous solution’s PH not the Heptane.
You want to test the water coming out of the wash and ensure it matches the water you put in.
Once its the same PH i usually do one or two more washes for good measure.
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Awesome this is great info! I’ve always tested both, using the water and clean heptane as a baseline so I know when the ph is finished swinging.
But if I only need to test the h2O then I’m definitely going to dust off my digital meter. I HATE the papers…
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I’m not sure how you are even getting a reading testing the heptane as hydrocarbons dont have a PH.
The readings you get from testing heptane should not be considered as valid data.
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Maybe I’m not getting a reading, it is always around 3 - 3.5 on the strips but now that I think about it thats the same color of the strip 
However when I have the distillate dissolved in the heptane I will actually get a low or high reading which does provide some usable data.
I would partially disagree. The traditional pH meter usually measures based on electric current but most organic solvents are not conductive…but you can still mix organic solvents with organic acids (take acetic acid and hexane for instance, they are miscible to some degree) so there would technically be some sort of a change in pH. I think that color changing pH is adequate for this, if anything to get a relative change.
The concept itself may not directly transfer over and the use of an actual pH probe may not work, that doesn’t necessarily mean there isn’t an acidic or alkaline component to the organic solvent system.
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ive killed a few blue labs; they suck; get a proper bench meter if you plan to use it every day, well worth the investment.
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I’ve ran through 3 of them. Yeah, I agree, go with something else
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What is a recommended meter
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As an aside I just bought the blue lab auto ph meter and I hate it. Prolly gonna bring it back for store credit. I like the $25 dr. Meter one on Amazon better then this $420 pos.
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Any updates on this topic? I’m having a lot of trouble finding a decent probe to work with non-aqueous solutions. I understand you can’t use a probe designed for water, but I want to make sure that the conversion I’m doing are safe to send to the public. I don’t necessarily trust testing the waste water, as I have had conflicting results testing the same water with different strips of paper. I’ve also reached out to multiple vendors and they also can’t really seem to help, which is actually concerning. LOL. Any advice or direction on this topic would be extremely appreciated!
The concept of pH doesn’t apply to non-aqueous systems. You can have protic solvents that may dissociate protons, but that won’t be measurable using a pH meter.
pH is the dissociation of H+ and OH- from HOH (water). It is literally the negative log of the concentration of H+ ions in aqueous solutions.
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Cool, understood. Thanks! How do I know that a product I’m converting is safe for consumers then? Trust the pH of the waste water? I’ve done like 6 washes at this point.
That’s generally what happens. When you do LLE, the aqueous part reacts with the nonaqueous and changes the pH of the aqueous part.
That’s general organic chem, someone who has experience should verify as I’ve never done LLE with cannabis extracts.
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Your water phase is going to be much more prone to solubilizing your ionic molecules. We do LLE with our extract all the time (not a conversion, but a similar process) but we never measure the pH of the non-aqueous phase, we measure the pH of the water phase before addition if we’re doing an acidic or alkaline wash, and we measure the pH of the waste water when we do our neutral washes. Normally our last washes go in neutral, but come out either acidic or alkaline (depending on if the previous wash was acidic or alkaline). And we will continue to do neutral washes until our waste water measures neutral.
It could be a different story if you are doing a conversion in your case, but I would still trust the pH of the waste water. If your conversion has ionic components to it, they should be soluble in your aq. phase and as long as you continue washing until neutral you should be good to go. If you get a neutral waste water, do another one or two washes to be sure.
If you are concerned about trace amounts of residual in your final converted product, and you know what acids you may have present in the converted product, then send a small sample out for testing. If it’s a known molecule that is compatible with mass spec, either LC or GC, you can probably detect if it is or isn’t present.
edit @TpaTHC If you do have a pH meter, another small test you could do is warm up your conversion material and some water to maybe 65C, and mix them together in a small amount with a stir bar, maybe do a 1:1 or a 1:2 (1 part conversion 2 parts water). I understand they won’t necessarily be homogenous but if you can mix them with enough agitation, you can probably get a temporary emulsion that will persist while you keep mixing. You may be able to get a pH reading on this solution due to the presence of water even though part of this solution may be non-aqueous. I don’t know for sure but it could be worth trying out.
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Awesome, thank you so much for the advice. I’ve typically measured the waste water in the past, but since I started this new conversion I have been getting some pretty weird results. I’ve split batches, washed them the same way, but have gotten two COMPLETELY different readings, which has really made me uneasy. I bought paper to help settle the confusion. It just made it totally worse. It’s made me question everything I thought I knew about LLE, washing, neutralizing and orgo in general tbh.
I tried doing the 1:1 homogenous mixture test and it was unsuccessful. Maybe 2:1 would work. I’ll give that a shot later today. I finally found someone at Mettler Toledo who suggested a decent probe. It’s a bit pricey, but I suppose it’s worth knowing that my oil is safe to send to consumers. I’m also under the impression that analytical labs can’t test for this acid. However, maybe I’ve spoken to the wrong people.
I appreciate all the help guys