Episode 169: Uncovering THC Potency Variability with Cannabis ChemLab

Welcome to the Cannabis Cultivation and Science Podcast. I'm your host, Tad Hussey of KISS Organics. This is the podcast where we discuss the cutting edge of growing from a science-based perspective and draw on top experts from around the industry to share their wisdom and knowledge. Just a reminder that as of this podcast launch, the Cannabis Cultivation and Science Conference is less than a month away. The workshop spots are already full, but there are conference tickets still available. It's going to be an amazing event, even better than last year, and we rented out the Elm, a 1,200-person concert hall, for a Saturday night tasting and sensory experience where you can sample the best of what Montana cannabis has to offer, all included with your 3-day conference ticket. You can learn more about it at kisorganics.com, or we now have a dedicated website at cultivation.science just for the conference. Now, on today's podcast, we're diving into the analytical science of cannabis testing, specifically looking at potency variability, chemical standards, and heavy metal accumulation. Our guest this week is Jared Neuenheiss, an entrepreneur with over 11 years of experience building and maintaining laboratory operations. He is the founder of Cannabis Chem Lab, an ISO and IEC accredited analytical laboratory serving the South Dakota medical cannabis program and USDA hemp growers nationally through quality assurance, regulatory compliance, and industry education. Jared's extensive background spans environmental testing, laboratory development, method validation, quality management system development, and commercial farming. In this episode, he shares eye-opening research his lab conducted on cannabinoid standards explaining why the exact same sample can yield wildly different THC percentages depending on the calibration curve a lab uses. We also dig deep into heavy metal contamination, why ocean-based inputs aren't as clean as marketing claims make them out to be, and practical strategies growers can use to mitigate heavy metals in living soil. Now onto the show.

Hey, Jared, welcome to the show.

Hey, Tad, how's it going?

Good, good. I really appreciate you taking the time to come on the show and talk a little bit more about the lab perspective and some of the challenges associated with running a lab. Can you give listeners a little bit of background into who you are and where, how you ended up in this role?

Yeah. So basically I, right outta college, I started my first laboratory, East Prairie Labs, and we did soil, plant tissue, manure, feeds and forages. Uh, basically all things agricultural. From there, uh, in 2020, we, uh, in South Dakota passed recreational and medical on the same ballot. That was pretty cool. Uh, but rec got repealed. And so we were able to maintain medical. And based on that, uh, the Flandreau Santee Sioux Tribe invited us to do their hemp testing, which evolved into doing their cannabis testing. And that put us in the position to be the only laboratory in the state when licensing came about. And so we did a bunch of work to develop methods in that time, you know, get our accreditation materials together and just start building the laboratory out for commercial use. As the years went on, we developed processes within the lab to improve everything from our turnaround times to our customer satisfaction. And we just worked hard to get better and better over time. And that's in large part due to the work of Adria, our CEO.

And now you're expanding into Minnesota for folks in Minnesota as well. And we've been using you for heavy metal testing on all of our, all of our inputs, soils, water, all of these things too. So it's been great to work with you, but I want to just dive in with the, the biggest question that I think growers have right off the bat, which is we often hear about potency inflation or lab shopping in this industry. How do different standard operation procedures or calibration methods allow one lab to return a 28% THC result while another lab returns a 22% THC result on the exact same batch? Because growers are so reliant on these, specifically the THC numbers, to sell their cannabis at a good price.

Exactly. Yep. It's all market demand. Yeah. So basically in, in the process of, you know, working through setting up our first lab, we uncovered quite a few different aspects during method development that really play a role in setting up your lab for success when it comes to potency testing. And it's great for the growers too. The hard part is, is coming up with you know, the ability to do the research, but also the time and money that goes with it. When we were the only lab in a small state like South Dakota, our sample load is not what it is for most other states. So that gave us some leeway to do this kind of research and really perfect potencies.

Jared, just so I understand too, because you and I have talked off air quite a bit about this. Yeah, there's, there's no standard methodology for all these different practices, like necessarily preparing a sample or how, how the lab creates the result that they do. There's different ways that people can achieve this, the same, you know, get a potency number. Can you talk a little bit about what, what those challenges are with variability there?

Yes. So one example of, uh, you know, the difference between laboratories' SOPs could come down to their sample preparations. Some labs will freeze their flour before they homogenize it. Some labs homogenize it at room temperature. It's all based on what they were able to think of at the time for how to do the sample prep, um, and what they committed to and built into a commercial set. For us, we found that Geno Grinders work best for homogenizing flour when frozen. And the reason we freeze it is because that has a direct impact on the, uh, potency and, uh, several other aspects, uh, that flour likes to cling to those stainless steel balls. And so By freezing it, we're able to keep that from happening and give true potency numbers for the flower. But the variability doesn't just stop there. It continues on throughout the process. You know, each lab might have different extraction solvents, different volumes. Volumes play a bigger role than the solvents themselves. Yeah, so there's a lot of variability between labs just based on how they developed their test methods.

Well, let's, let's touch on that really quick because you had mentioned there was a pretty big difference between just freezing the sample versus preparing it at room temperature. What would you, what would you see in a difference in terms of THC results just with that simple change?

Well, it's really interesting. What ends up happening with at room temperature is the cannabinoids, all the trichomes end up sticking to the stainless steel balls and they just build up over it almost like, like a rubber band ball. And so they just continue to build over that stainless steel ball and attach to themselves. When you freeze it, that prevents those— those trichomes are cold, so then they also don't stick in the same way. Because of that, we saw a difference of, you know, 5 to almost 10% between those two homogenization techniques. Same machine, same instrument, same everything. It's just the difference of performing the homogenization at room temp versus it being frozen with dry ice.

And there's no governing body, even like the accreditation accreditation or anything like that that says, hey, you need to freeze these samples because it's going to give you a more accurate or higher potency result. There's nothing that exists like that. Is that right?

Well, if you can pass proficiency tests with it, that is about the requirement. When it comes to accreditations, they really look at your, your proficiency test results. They look at, you know, your ability to maintain data within the laboratory, to have traceability from everything from the filter that you used to filter that cannabis extract to the conical tubes. You know, we have— and all of that plays a role. That's how you figure out what your margin of uncertainty is for each of these test panels. So everything has a place in it, but the accrediting bodies don't specifically look at how you're performing, you know, and tell you that that's wrong if you can pass PTs with it.

And what, what is a proficiency test? Is that looking— I mean, I mean, I get that you're looking at all these variables, Yeah. But is that just telling you that your SOP is, that you, that your SOP is leading to a result that's accurate or what?

Yes. Yep, exactly. So when it comes to a proficiency test, laboratories enroll themselves in these to maintain their accreditation, but also to show that they are competent. So with that, basically the ANAB auditors look at those things more specifically than a lot of other aspects of the lab, but they don't really tell you one way or the other if you're doing it right. They're just looking at your process and seeing if it lines up with the ISO 17025 standard.

Okay.

So are you, when you're being proficient, proficiency tested, are you being compared with how other labs are? Like, will they send the same sample to another lab or how does that work to see if your results are similar?

So generally what they do is they have these blind proficiency tests ran several times, either in-house or amongst other proficiency test providers. And then once they have that average value, they'll assign a plus or minus 20 to 30% variance off of that. And then we get those samples, we have to test them with our method, deliver those results back to them, and then they tell us if we fell within range or not.

And this is all with cannabis that this is happening with.

Okay.

Cannabis.

Okay.

So I understand.

Yep, exactly.

Okay.

So there is some level of regulatory oversight to make sure that the lab is at least within a range, but 20 to 30% is, can sometimes be the difference between selling your product and having it sit on the shelf or not being able to move it.

Well, and keep in mind that it's 20 to 30% of the value. That is assigned.

Yes. So, okay.

Yep.

That's still a fair bit of variability. I realize that there's always going to be a standard deviation.

Well, I also thought that it was all very wide myself until we uncovered this standards thing and then it all made sense for me.

So let's, all right, well, let's dive into that because people don't know what we're talking about. So one issue of variability you mentioned was just how the samples prepare and you gave the example of the freeze drying versus room temperature. You did talk about volume playing a big role in terms of the size of the amount of sample that a grower uses. Do you want to touch on that before we get into the standards?

Yeah. So when it comes to volume, you mean in terms of the extraction?

Yeah.

Yep.

Well, how does, how does the volume that, yeah, the size of the sample used play a role, whether it's the same, the size that the grower gives you or the amount that's used by the lab?

So when we, when we're talking about sample volume, we're going to talk about the volume that's being used within the lab. If you increase that sample volume but don't increase the amount of solvent that's going with it, you essentially end up overloading that solvent. And so you're capping how much it can actually absorb by putting more and more sample into the same volume of solvent.

That's just— so it's almost like a solubility thing, like how much sugar can you dissolve in water? It's the same kind of thing.

Same concept. Yeah. Okay.

So it's— I would assume using a larger Sample size would give you a more accurate result though.

It would.

Is there a, is there a balance there?

It would give you a more accurate result, but that's kind of the purpose of your homogenization. So because we put in place such, uh, strict homogenization into our lab procedures, we are able to test the same thing over and over and over again within the lab and get the same result over and over and over again, because we've taken all the variability of that flower and compressed it by breaking it down into tiny little pieces.

So this is look almost like green flour by the time you're done with like a, like flour as in F-L-O-U-R, not flour, like baking flour. Baking. Thank you.

Yeah. Okay.

And it's dried out at that point too. All the moisture has been removed. So is there a difference then in terms of, because one of the questions I had since we're talking about this was, does it make a difference if you have a really dense bud or, you know, say a C quality or lower bud or something that's more larvey, how does that impact the results or does it?

That absolutely would. So when you're thinking about the increments that we're taking to make your, uh, test sample that we're gonna run on the instrument, just as important as the increments we're taking of that sample is the sample that was taken from the batch. So if you're going through and collecting buds to get a, you want to get a representative batch sample of it. But if, if you skew more one way towards the C side versus the A side, then you end up having, you know, multiple, uh, your variance grows larger. In, in South Dakota, what a lot of people went to is they would start separating their A's and B's and testing that and sending everything else to extractions. And that was really interesting because what we saw is that their potency variability has dropped., quite a bit and they had a more standardized, between batches or harvest, they had a more standardized, potency range.

I know this is a dumb question, but how does variability differ between A, B, and C buds for people who may not be familiar?

Basically, it's, it's not only the, quality of the buds in terms of what you guys are able to sell them for. I know it's based off of,, you know, aesthetics, but also lab test results. When it comes to us, what we're looking at is the concentration of terpenes, cannabinoids, and trichomes. We want to look at buds that have a high concentration of those. If you do separate the A's and B's out, then typically you end up having buds that are more uniform with those concentrations. So versus including everything in one batch, then you're potentially sampling more of the lesser concentrated buds, if that makes sense.

What you're seeing then is higher, higher THC and cannabinoid content in the A quality buds versus B or C, as just as a general rule.

Exactly. We're looking at the quality of the buds. We're looking at, you know, when you're the one collecting the sample, like we did in South Dakota for a long time, it's our job to collect a representative sample of the entire batch. But if they separate out the A's and B's, we saw that we got a tighter window on what their potency range was for the customer.

Yeah. So you mentioned that this idea of standards is something that you've, you've unearthed as being a real challenge for the cannabis industry as a whole and specifically your lab. How does Cannabis Chem Lab handle sort of that baseline calibration preparation to ensure that your potency profiles are, you know, legally defensible and scientifically honest? As in, how do you know— what are you comparing your THC to? Because you have to have, you know, what is called a standard. Can you describe what a standard is? And, and maybe start with something that's not THC, but, but another more generally understood or universally used analyte or something?

Yeah, maybe we could do heavy metals.

Yeah. So I want to come back to standards and not go too deep in heavy metals, but let's just say lead, for example. Like, how do you test a sample for lead and know that what you're getting is accurate?

Yep. So what we end up doing when we're purchasing commercially available standards is we're looking for ISO accredited standard providers. In a lot of cases, the instrument manufacturers like Agilent are also ISO accredited for manufacturing standards. Which is very convenient. So what we do is we purchase the available commercial standard. It comes at a concentration, let's say 1,000. It's been tested, it comes with a certificate of analysis, and it shows us exactly what's in that bottle. So we have 1,000 ppm of lead, or micrograms per milliliter. And what you would do is take some of that, dilute it down with a known volume so that you're basically doing ratios the same way, like, if you're at home and you're mixing pesticides or herbicides. Ratios are exactly the same thing, just in the lab we do it with more accurate measuring instruments. So essentially what we're doing is we're taking that 1,000 and we're diluting it down to, let's say, 100, 50, 25, 5, and 1. Based off of those concentrations, what we're able to do is inject each of those into the instrument establish what that concentration is on the instrument and then draw a line between each of those concentrations that delivers a calibration curve for lead.

And that calibration curve is— it should be a straight line, which means that everything is lining up exactly like where you— where the— when you stick the 20 ppm into the machine, what you expect to get out is exactly 20 ppm, and then the same for 5 And so that, you know, that as long as your standard is accurate, you've exactly hit all those points. So then when you run an unknown sample, in this case, maybe some soil or something that can potentially contain lead, you can very accurately determine what the amount of lead in that sample.

Exactly. Yep. That's exactly right. Awesome.

So how does this work specifically with THC and what are the challenges that you're finding? And then. On that note, are there other companies besides Agilent that make these standards, or is everyone getting their standards from the same company?

No, um, there are several companies that make standards, uh, several ISO-accredited companies. You know, in Potency, one of the things that we did to try and figure out what was going on with THCA specifically was we purchased standards through all of these different manufacturers. I think we purchased around 30, 35 separate individual standards from everybody from Cayman Analytical, Agilent, Millipore Sigma, Cerilliant, you know, Absolute Standards, basically anybody that— NSI, LGC, anybody that we could contact to get individual THCA standards is what we did, short of making them ourselves. And so in doing that, what we found in you know, taking that exact same process that we talked about for lead and doing those dilutions with gas-tight syringes under the same conditions for each standard in the HPLC— I'm sorry, UPLC. We also have a refrigerated auto sampler. So even as they're sitting there, they're under the same conditions. What we did is we injected each of those sets of calibrations that we created from these manufacturers. And as we did that, we saw absolutely perfect curves for THCA. We're like, okay, well, that's good. That means we did good dilutions. But what we saw was that the— when we overlaid these curves on top of each other, we saw slopes that were vastly different. So you end up with something. Is it all right if I draw it out on the board?

Yeah. For those of you that are just listening to the podcast, I'll try to describe what Jared is drawing. And then for those of you that are able to go to YouTube, you can actually see the video of this all posted on YouTube for folks., but essentially, yeah, if you want to draw sort of what that looks like for folks, we can kind of get an idea.

Okay, so essentially what we've drawn here is just an XY axis. So if you guys can see this here, so basically when we're looking at a curve, we're looking at these points that we talked about, right? So this one here would be 0, that's our origin point. Our first cow point would be about here, here, 3, 4. In potency, we do 5-point calibration. In pesticides, we do 8 points. It's totally up to the laboratory for how crazy they want to get on their cal points.

And cal point stands for calibration point?

Yes.

Is that correct? Okay.

Yep. Sorry for the slang.

That's okay. I was just guessing, but that sounded like what it might be. So is this line expected to be perfectly straight or should it have a curve to it?

Well, what ends up happening is there's linearity within a certain range. So what ends up happening is this will start to curve off one way or another at some point, kind of like this up here, if you guys can see that.

Okay. So it's like a 45-degree straight line that then curves at the end of it, kind of tails off in one direction or the other.

Yeah. And so it'll kind of look like a curvature. So that's why you kind of pick like a specific range for your curve to sit in where you know it's linear. And that's what we have right here down to zero.

So when you do this with, when you did this with all these different sample, all these different standards, sorry, and then put the exact same homogenized sample into it, what did the results look like? What was the variability there?

Well, basically what ended up happening was, uh, as we applied the samples, the unknowns to these separate curves, we saw on several of them that the lower the curve showed, the higher the concentration. So like Agilent had a curve that was lower compared to some of the others, and that gave a higher flower value, say 25% versus some of the others that gave it a 14. Now, keep in mind that these samples were prepared in exactly the same way, like we said earlier. So it all came down to just this difference between standards. So, you know, that to me was kind of eye-opening because as a laboratory, you try to do the best science you can. But what if the materials that you're working with aren't what you thought they were?

So just by switching the sample that you received or the standard that you received, that exact same sample could test at 25% THC or at 14% using all the same methodology in your lab.

Yeah. Yep. Essentially what we did is we took that HPLC vial that was, you know, extracted all the way through and prepared, you know, one to go for each calibration point. So you end up with like 30 to 35 HPLC vials of the same sample, you know, but then it can be replicated and ran several times to show that it's not just a one-off, that it is, you know— if I put this on the board, you guys will see this much easier. So between like absolute standards you know, Millipore Sigma, you end up with something that looks kind of like this, because when you get down to zero, they're all going to end at zero. But as you go up and up and up in concentration, you get up here to the point where you're testing, let's say, diamonds, right? Where you have something that's, you know, 99. Well, if you are testing that up here at the top range of your curve, That's where your labs are reporting out your 120s and your 110s and your 105s.

Well, you mean above 100% THC, which is impossible.

Exactly. But it's not impossible because the standards say, you know what I mean? Yeah. So that's, that's the hard part for the labs is like, unless you have the time and the energy and the money to figure this stuff out and do all that, because, you know, a lot of labs like here in Minnesota as they're starting up are just slammed with samples. So how are they going to find the time to figure this out?

So as a grower, this is really frustrating because we don't have any control over this process. Well, we don't know what samples you're using too. Well, yeah, you'll probably get a lot of flack from it, you know, for it. So how, what can we do as a grower about this? Or is this just a universal issue that people should just be aware of? So it's not necessary, I guess, I guess to me, this isn't, this is sort of passing the buck. It's saying, hey, it's not. Always the lab that's inflating the numbers. It's because the standards that they're using may not be accurate, which I hear. But how do we— what do we do about it?

Well, I think we need to perhaps educate some of the labs about it because a lot of them might not even know that this is happening. The other thing is talking with the regulators to see if we can get some sort of a solution figured out where a lot of labs are on the same set of approved standards through the state. You know what I mean? Like, uh, LGC is a great company, but there's lots of others.

Yeah.

It would be great if everyone in the same state was at least using the same standard. I think that would— so that, you know, you could at least compare across each other. But then to further complicate this, didn't you say that you also saw variability from the same company on standards themselves, I believe?

Between lots. Yes.

Yeah.

Yep. So that's the other part of this expanded study that we're doing is looking at, okay, we see that there's variability between each of these manufacturers, but what about their internal process between lots? Is there variability, you know, between one Agilent THCA standard from a lot made in July and one made in August? So that's, that's the next phase of kind of what we're looking at. And what we found is yes, there is variability amongst some of the manufacturers between lots.

Now that's just, that's just crazy to me because it's something that we are so reliant on and we, we see it on a piece of pa— we see a THC number on a piece of paper and we just, as a grower, you just assume that's the amount of THC in there. But what I'm hearing is that it can actually be a pretty wide range of what, what's really in the product. We don't really know then.

Right. And so, uh, this issue of like lab shopping, that can come from dishonest labs doing, you know, all sorts of things. Who knows what they could do? But in— I'm guessing in a lot of cases, like if you're getting low potencies from a lab or, you know, it's something that happened all of a sudden, it's probably coming from this and they don't know it yet.

So the issue could be labs have the ability to manipulate data, I'm sure, and— or they may have processes that are inconsistent. Or that lead to more inconsistent results. That's for sure entirely possible. But some of it too is even if they're very, very strict about it, it could just be that their standards— maybe they move to the next lot of standards because they ran out of one standard and then now, well, right, you know, we have parameters that guarantee quality within the lab.

Every 10 samples you have a CCV that checks that calibration. If anything starts to waiver off of what it's supposed to be, those previous 10 samples need to get reran. And so if that's the case, that comes with a potential recalibration as well. And so, you know, every time you recalibrate, you're using up what standards you have left of that lot. So when you mentioned one thing that we're doing to combat this, the only thing I've come up with so far as a stopgap measure is to purchase enough standards of one lot from one manufacturer to basically last us an entire year. But then you get to that point at the end of that where you still have to then go and find some more that match up more closely with the curves that you've been reporting on, because all of each— the frustrating part is that when you look at these on the instrument, these are all scientifically valid curves.

It's not—

so you're saying it's not necessarily impropriety on the part of the standards company, it's just the variability of Right.

Yeah.

I don't think so. Do you see this with lead?

Less so with lead. See, you also have to consider the fact that these compounds that we're talking about in cannabinoids do convert into their neutral forms over time. Lead does not do that in the same way.

It's more stable.

Yeah, you could think of it that way. Exactly.

Okay.

Okay. And it's— it's— It's very interesting actually, in the individual standards you will see Delta-9 peaks in there as well. And that will tell you that, hey, maybe the material that they used to create this standard wasn't as pure as they thought. You know, you should not see a Delta-9 standard in a THCA standard if that's what it is.

That's all really interesting. Do you see the same issues with other secondary metabolites, terpenes, minor cannabinoids?

Yeah.

Is this a prevalent issue across the entire— like every aspect of flower testing?

The acidic compounds do present more of a problem than the neutral— their neutral forms in potencies, whether it's CBDA or, you know, CBGA, CBDVA. All of those A's tend to cause problems in one way or another. It's just they don't get the, the same limelight that THC gets.

So anything with an A stands for acid.

Acidic.

Acidic.

Okay.

Oh, that's interesting.

Okay.

Wow.

Well, that's, that's really tough to hear for growers. So lab shopping is still, I mean, unfortunately a thing because, you know, even if these two labs independently are doing really rigorous scientific laboratory work, they may just, one may just have a standard that's a little less concentrated or more concentrated leading to higher difference in results. I mean, how, You said about 10% difference, which is huge. Is that—

especially towards the high end of the curve when you're testing diamonds or something with that high of a concentration of THCA is where you really see that.

What about with just flour then? Would you expect a much lower? Because that's—

you know, we still saw it depending if it was closer to like a 15 or 18% on average, the variability was a little bit closer. Um, but the further you got up here to like, you know, a 30% flour, that was where the variability really kicked in.

What do you think is truly the limit of flour, like the genetic potential of the plant based on the results you're seeing? Just out of curiosity.

Uh, I would say on average, probably low to mid-20s, but we, as people have dialed in their grow facilities in South Dakota, we have seen higher potencies come through and we can say that because we're using the exact same lot from the exact same manufacturer, and we have, you know, 20 ampules of that.

Is there a direct correlation then? As THC goes up, other secondary metabolites go down. You typically see less minor cannabinoids or terpene expression.

You can, but those things happen much more slowly than, than the time that that sample spends getting prepared. For extraction in the lab.

Okay, and if a grower gets a surprising result, like lower than expected THC percentage, is it worth actually retesting? What can they do?

It is possible. It is possible because, as we said in the sample collection aspect, it is possible to get better data and better potency results based off of a resampling. So that's one good tool that growers can use to get potentially better flower result. Because like I always tell our customers, I can only tell you what goes in the sample bottle about this batch. So that's one important aspect. When you're looking at labs, I would say maybe ask them for their PT results so that you can see where they landed on the, on the ranges that we talked about. And they, they should have that ready and willing to give it to you.

And that's their proficiency results.

Yes. Yep. For potency.

So what it sounds like we need as an industry is like a single universally mandated standard that would go across the country. Yeah, that would, that would really be the only solution that could fix this potency issue that you're seeing.

Yeah, exactly. Because another aspect of what we've done is, you know, we've purchased practice proficiency tests where we get the known values with the sample., and we've ran those against these multiple curves. And yeah, there's more data to support that the slope of these curves is actually very important when it comes to reporting unknowns on, on people's livelihood for how they make money.

So what, what did you use in determining what standard to go with?

You don't have to say the name of the company necessarily, but how did you determine?

Yeah, so essentially what I did is after comparing all of these curves and overlaying them. It compared the practice PTs. I compared the THCA diamonds that we had in-house to kind of check out the top line here. And so essentially what I did is I found anything with THCA that I could check along the curve all the way down and compare it to previous results. So, uh, diamonds, I checked those out at the top. Any of the higher concentration flour I could get my hands on. Kief would be another good one. And then going down the line to just lower grade flour all the way down to hemp was kind of how I approached it. And so what I did is I just found that average line that was right in the middle of all of these for the slope, and that's the one I went with because in my mind, that's the, the middle, that's the average, that's the Goldilocks zone. And then I bought, you know, 20 ampules of that one lot.

So you as a lab owner didn't even choose the highest reporting standard?

No, no. Our goal has always been to report the most accurate data for all of— for everything that we do, especially when it comes to labeling potency. Because if somebody takes a flower or, you know, whatever it is, something with THC in it and ingests it, they're going to be really disappointed if they bought it at 30% and it feels more like 12% or, you know, vice versa. You know, what we do is we are like integrity. We guard that very seriously.

In theory, though, a lab could go through this process and then pick the standard that produced the highest THC results. And then they could scientifically defend those numbers based off of this process that you're describing here, because it is considered an accredited standard or accept universally accepted standard.

Well, the other thing I'll mention also about why we chose the middle is that we also do a lot of testing for law enforcement as well. And so, you know, you have to find the. The correct one that is gonna be the fairest and most, what's the word I'm trying to come up with, but—

Representative, maybe?

Yeah. Representative of the entire mess of standards that we have to deal with.

And how, how does this vary then when we talk about flour versus say, like gummies or other edibles and things like that? Like if my, if I buy something in a store that says that this gummy contains 10 milligrams of THC. What's the actual range that could be expected?

So in your head, in that, for that gummy, that's a good question because that brings up the, all, all of the neutral forms. Like when you convert to THCA and decarb it into distillate, let's say, you're kind of eliminating that problem for us because now we're just testing the neutrals and the variability on those is quite a bit lower than what it is on THCA specifically.

So you feel like those are a lot more accurate?

Yeah, but that's not to say that they, they're more accurate than this is what I'm saying.

Okay.

Yep. Their, their spread is much tighter, more of a rifle than a shotgun.

So if I were to consume that 10 milligram gummy, I'm probably getting somewhere between 9 to 11 milligrams of THC, or am I getting somewhere between like 5 to 15? How tight is that?

It's going to be tighter. It's going to be tighter than that because these manufactured products are, are dosed off of calculators. They're very— if they're manufactured correctly at 10, they should come back at approximately 10 per unit.

Okay, well, that's good to hear. Okay. Well, is there anything else you want to talk about in terms of flower or cannabinoid testing that we didn't cover?

I guess You know, stay tuned because I'm going to continue to do research on this and figure out more in terms of, you know, within these manufacturers, if they'll talk to me about it, how are they manufacturing these standards, and then try to figure out where the differences are between each of these different processes that we are— that all labs are purchasing.

Yeah, and last question then on this topic then would be, is everyone using ICP-MS, like the same machine? And then does the age of the machine make a difference in terms of results?

Yes and no. The machine itself is there to pump solvent and water at a specified rate and then to detect it on the back end where the flow cell is. The column that we place inside of that instrument is what does all the separations for the cannabinoids. That's how we're able to split them apart and see each one individually. In terms of instrumentation, you know, I can run potencies on an Agilent 1100, which is a model that's been around since the early 2000s. And then I could also run it on one of our new UPLCs here in Hutchinson, and with the exact same column, get very similar results based off of that. It really comes down to column chemistry and what your, what your mobile phases are within the instrument.

Okay. Yeah, I'm not going to lie, you lost me on that one, but—

Sorry.

No, it's fine. So as everyone, everyone is using ICP-MS though for this type of testing.

No, ICP-MS is for heavy metals.

Oh, for heavy metals.

Okay.

Sorry, I switched over.

So yeah, HPLC or UPLC. Are the terms for those two.

Got it. And they're testing though, in terms of the accuracy or precision of these tests, they're to parts per million, to parts per billion?

Parts per million.

Parts per million for cannabinoid testing or potency testing. And then when we see— I'm much more familiar with the heavy metal side. Yeah, there we're talking, you have the accuracy or precision to go down to parts per billion for that, correct?

Yes. And the difference between that actually has to do with the detectors. So on the UPLCs and HPLCs, we're looking at changes in wavelengths of light, whereas over here on the MS side, we're looking at literally the mass-to-charge ratio of the ions that we're pushing through.

Mass spectrometry, if I can—

Yes.

If I said that correctly. All right.

Yep.

So let's jump over to heavy metals, which is something that I've— you and I have talked about quite a bit about, and we've done a ton of testing with you, with you guys on. Where, where are you seeing issues happen for growers in terms of heavy metals, in terms of, you know, specific inputs? And I'm not talking like brand name products, but things like alfalfa meal or soy meal or things like that.

Fishbone meal.

Fishbone meal.

That's a huge— I've seen that come up in South Dakota. So when it comes to inputs on heavy metals, one thing we found is that it doesn't really have to do so much with the water that's coming in. And what we've tested, you know, usually the water has been pretty clean. Hmm. What it really comes from in what we've tested and seen is a lot of the inputs that go into the soil when you're trying to regenerate some of the nutrients that have been taken out by a previous harvest, or if you're trying to amend the soil, you know, as you're going along with the harvest, any of those kinds of inputs can add heavy metals to that soil substrate, which then become available every time you add water to the plants themselves, and they love to take it up. So fish bone meal for arsenic has been definite no-go for the people in South Dakota.

And I want to be clear, all— pretty much all, not all, but almost all fertilizers and inputs have heavy metals. They're ubiquitous. We're surrounded by heavy metals all the time. We're exposed to them all the time in our environment. However, some of the regulations in various states are very, very tight for heavy metals. Cannabis is a hyperaccumulator, so it's going to pull these up. Really quickly. And there's, there's things we can do to reduce the amount of heavy metals that are taken up, whether it's by adjusting pH or the environment itself. However, by the biggest thing that a grower can do is reduce the amount of heavy metals in the media or in the soil. And that's through this testing that you're talking about.

Exactly. That's been the most successful strategy that we've seen work for soil growers in South Dakota.

And you say fishbone meal is tough because it's higher in arsenic. You know, there's been a big push towards, by some companies towards not using meat industry byproducts because they're quote unquote, you know, dirty in the meat industry is horribly unethical. How clean are those products like blood and bone and feather that you've tested relative to ocean-based? So meat-based inputs versus slaughterhouse waste versus fish— fisheries waste?

Yeah, well, what I'll say is we've had more exposure to the fisheries waste than we have to the blood and bone meal. But from what we have tested, I would say that that is cleaner than what I saw coming from the fish bone meal from a heavy metal perspective. Yeah. And then the limited testing that we've done for some of the other ones, like I say, the fish bone one is what a lot of people were using.

And that aligns pretty closely with the testing I've seen, research I've seen as well.

So that does, that does align there.

And I just want to throw out there to people, and you can comment on this as well, that compost, while a wonderful input, it contains a lot of good microbiology, is probably the most contaminating input in a grow if you're using living soil or things like that because you're using such a high volume of it. So the application rate tends to be higher., but it also tends to have more contaminants, whether that's heavy metals in this case or other things.

Yeah, absolutely. Yeah, because anything that you add to that soil is going to find its way to the roots eventually. So yeah, any amendments you do, I would highly recommend screening them for heavy metals before you apply them.

And then one of the things that I found is been very, very clean across the board has been insect frass.

Yes.

Have you had the same result too?

Yes, that has been very clean. Yeah.

So hopefully people do their research around this. You know, we've worked really hard with you with coming up with soils that contained a lot of fertility, but, you know, still contain fertility, but were very, very low in heavy metals.

So that's been really challenging but worthwhile.

Yeah, it's been a really good process. But it is, like you said, it is a challenge. Have you tested any like ferments or, you know, like fermented plant juice products or things like that? Extracts or something, or even compost tea? I mean, I was thinking more of these anaerobic ones, but have you tested— or let's just say commercially available products in general without naming brands, any like—

as, as for the micro— as for the microbiology, I haven't seen much of that come through the lab for heavy metals. Testing. Most of the inputs that we've seen come through the lab are more nutrient-based.

Have you had, you know, without naming names, any commercially available nutrients that were shockingly high in heavy metals, or has everything been pretty good?

It's not that we've seen any that are shockingly high outside of the fish bone meal. That one was quite a bit higher than what we see in the others. It's that through— you're not going to fertilize just once with this material. And so essentially what we're seeing is, you know, it's present. And so if you continue to apply with that fertilizer, it's going to continue to be present and then build up in your soil. So we don't— like, when we run heavy metals tests, we don't tell people whether we think it's high or low. We leave that for them and their judgment. We just tell them, this is what we found in your sample.

So you do see variability though across different commercial products or commercial lines. And, and you bring up a very good point in that, uh, yeah, we should, we can expect to see a little bit of heavy metals and everything, but the application rate and the concentration of those heavy metals over time, especially if you're reusing your media, can build up or cause, more likely cause a fail.

Now, if I saw something in the, you know, 50s to 100s, you know, part per billion. You know, when it came to the Fishbone Meal stuff, I called them right away and told them, you know, huck it in the trash. But when it comes to this other stuff, the levels are low enough that you can apply it, but then you have to keep in mind that it's going to accumulate in your soil.

Well, and there's no, there's no number. We can't say at 5 ppm of arsenic you will absolutely pass or fail, right? That just does not exist. So Genetics, environment.

Yeah, the roots are doing their own thing and taking up what they need. So if they take up arsenic at that point in their life cycle, then that's what happens. You just hope that you can get to it before that happens.

Yeah, it's a, it's a complicated, multifaceted equation, I guess, in terms of how plants accumulate heavy metals.

And so, yeah, we really just got to take a more holistic approach. Yeah, holistic and look at your strategies. You know, what can you do to limit what can go into that plant?

And have you tested— well, you have tested plants for heavy metals because you have to do that part of your testing. Can you touch on how different parts of the plant contain different levels of heavy metals?

Yeah, so one thing that's been interesting is, uh, you know, between the leaves, stems, all of that material into the flower A lot of the heavy metals sticks with that biomass. So we've had, you know, home growers say, okay, well, I grew this, it has some heavy metals in it. I'm going to try to press that into like a live rosin and then bring it back for testing. They did that and the heavy metals concentration was almost zero. So it's not to say that this material is like totally unusable. But when you do have heavy metals, it does accumulate in the biomass itself. So the flower gets it. But one strategy that I have heard work is if you leave the lower leaves on the plant, the more mature ones, they can act as sinks across the plant for heavy metals to accumulate in versus traveling up to the flower.

Yeah, from the research I've seen, Older growth, older tissue, as well as roots will accumulate heavy metals at higher concentrations than new materials, similar to say like a mobile nutrient.

Yes. Unless you're trimming those off, then, then it has to go somewhere. Sure.

So the idea being that by at harvest, removing the majority of the root mass, removing those old leaves rather than dropping them onto your soil would be a good practice from a heavy metal perspective, mitigation perspective. Mitigation.

Yeah.

Okay.

Yeah, I think it— I think when it comes to heavy metals, it's all about just mitigation strategies because you're never going to be able to eliminate it.

Yeah. So the way we approach it at Kiss Organics is first off is exclusion. So we try to limit the amount of heavy metals making it into the media. The second thing we do is we test everything going in so we know what levels we're adding. And then we can, you know, we, we use— and we use input specifically to manage heavy metals in terms of biochar in terms of pH, what pH range we like to stay in, all of these things. And then the, you know, practices that are going to help reduce heavy metals over time, which would be things like removing of, of, you know, organic matter, leaf matter, all biomass, all of that from the system. And then the biggest thing is we say, okay, so here's, it's kind of like a mass flow equation. So here's the level coming in at, you know, let's say this level and I'll just give it an arbitrary number of 10, right? So let's say we're at 10, and at 10, we're passing heavy metals by the state. It's not ever going to be zero. So let's say we're at 10, and 10 passes. Well, what we want to do is have our inputs that are going in not push us above 10, and have our outputs coming out in the flour, in that biomass, either help us maintain a 10 or drop the levels over time to maybe, maybe 5 is the sustainable level. You know, again, these are just made-up numbers, but The idea being that what comes in is less than what's going out, right? What is in there all the time is below the threshold for— yeah, the action point, or, you know, what allows you to pass with your flower, right?

Exactly.

And so that's, that's worked for us, but it is, it is a challenge, you know, in some of these states, then it's very low. So we have to start from a very, very clean product. And there's a lot of things that people don't think of that can contaminate a grow.

And so far as I'm aware, you guys are one of the only producers of soil that are going to these lengths to make sure that people can pass heavy metals, you know, doing the work.

Yeah, I can't speak to—

I know there are other companies that are doing some testing around it too. I can't speak to it too deeply.

But just from the lab's perspective, I'm impressed by how much you guys do.

That's because we do all of our testing with you guys. You see it all. But no, I appreciate that. And it's been, it's been great working with you on that because it does give me a lot more confidence every time we get another test result, you know, specifically for the growers that are also working with you to get their flower tested. Then you have, we have data showing what our levels are at and then how that's translating into, you know, the plant tissue. So that's been really useful for us as a metric for determining if we can confidently say, hey, you know, we can never guarantee, you know, if you're in a tight state that you're going to pass. But we can say, hey, we have a lot of confidence that this methodology works and we've done it with a variety of different growers across a variety of different states.

So that's, that's kind of where I stack the deck in your favor as much as you can.

Yeah. So I really appreciate that. Is there anything else that you would like cultivators to understand about lab, lab testing, lab practices?

I think I would say. That your laboratories are probably doing the best they can with what they have. And so if there's more information that, you know, a lab has time to figure out, that's why we're here talking about it. We're not trying to gatekeep any of this information because we feel that people need to know about it so that we can make better informed decisions from a lab perspective for our customers. And then the end result of that is, you know, the people purchasing the product.

Yeah. So As a grower, if I get a result that I'm not happy with from a lab like yours, what steps would you want us to take as a grower to try and remediate or fix, you know, come up with a solution that makes sense for everyone?

The first thing that I always suggest is a resampling of flower to see if the original sample may have contained more stems, twigs, whatever, more or less than what the original batch is. By getting a second crack at that, you're really giving yourself the chance to have an entirely new potency number. I've seen one sample collector collect it and it come back at 15. Another sample collector collect it and it'll come back at, you know, 18, maybe 19. So we're not talking huge swings here, but we are talking You know, and it can also go the other way too. So you got to be careful.

Yeah, I think the biggest takeaway for me is that none of this is static. It's— these numbers are not etched in stone, even though we see them on a piece of paper and we kind of treat them as such.

Right.

It's important to understand that there's some variability there.

Well, everything we do, when you think about it, is built on averages. We're taking an average of that, unless we were going to pulverize the entire— in South Dakota, it's 50 pounds is the batch limit. If we were gonna pulverize that entire 50 pounds, we could tell you with 100% certainty what the potency value is, but we can't do that 'cause then you don't have anything left to sell. So what we're doing in analytical testing is we're essentially taking averages of that batch, taking increments of that within the lab with another set of averages, running it through extractions that all have their own set of standard errors in bottle-top dispensers and everything else, all the way down to the instrument and to these cal curves. So if you have, you know, potency issue on flour, if it's a THCA issue specifically, I think a resampling would be a good strategy. If it's a concentrate product or something like an infused product, those are probably going to be exactly what they are. If you send them to another lab, they're probably going to come back pretty close. If they're over their dosage limit, um, then somebody probably had an issue in manufacturing. So, but that's to say for those infused products. When it comes to concentrates and you get a lab that reports back 120, everything I just told you about these cal curves is what's going on with that. So if that's the case, I would send it to another lab and see if their cal curve will match up with it. The lab shouldn't report something over 100%, but we've seen it done. So that— those are the suggestions I would have. If, if it's flower, I would submit for a resampling. If it's concentrates, I would take it to another lab. And infused products are generally going to be very stable between labs.

Great.

Well, I really appreciate you taking the time today to kind of explain the lab perspective to all of this and help growers better understand just sort of the variability in all this process and how we can reduce it as an, as an industry to get more accurate numbers and potentially get, you know, better numbers for, for flower and for selling.

And if there are any labs watching, just, you know, find the standard that works good for you and buy, you know, a year's supply of it and you, you won't have problems for a year, at least to be more consistent. After that year's up, you know, then you're back to square one. But at least we can sort of limit the variability from the standards perspective by purchasing bulk. Standards and having one lot that you use throughout the entire growth year.

Do you tell growers when you're switching standards then so people will know that, so they're aware of that, hey, your numbers might fluctuate now?

Yes, when we get down to that last ampule, you know, that's when we start saying, okay everybody, we have to do some research here and figure out, you know, we, and we've gone with, you know, Millipore Sigma and LGC, and those two have been the most accurate between lots and also between each other.

Great. Well, again, thank you for your time today. And for folks that are interested, you do do heavy metal testing, like you said. So it doesn't matter what state you live in for that. But if you— so, and we, we sell those tests directly on our website. It's $99 per sample, which is a very reasonable price for heavy metal testing. And then if you are looking for potency testing, your labs are currently in South Dakota and Minnesota.

Hutchinson. Yep, Hutchinson, Minnesota.

Nice. Well, thanks again, and we'll stay in touch.

Awesome. Thank you, Tad.

That was Jared Neuenhuis, and you were listening to the Cannabis Cultivation and Science Podcast. If you like the podcast, please leave us a rating review and give us a follow on Instagram and YouTube. And don't forget, at KISS Organics, we have a wide array of products we offer on our website, ranging from soils, amendments, beneficial insects to soil test analysis and commercial consulting. We carefully research all the products we offer and manufacture to make sure they are science-based and meet our highest standards of quality. Thanks for listening.