Tag Archives: lab

October 17, 2016

Steep Hill Labs Expands to Pennsylvania, Washington, D.C.

By Aaron G. Biros

Last week, Steep Hill Labs, Inc. announced plans to expand on the East Coast, including licensing for laboratories in Washington, D.C. and Pennsylvania. The cannabis testing company now is operating or developing in seven states, the District of Columbia along with an official arrangement with a research university in Jamaica, according to Cathie Bennett Warner, director of public relations at Steep Hill.

The same team of physicians that oversees the Steep Hill laboratory in Maryland will operate the Pennsylvania and D.C. labs. Heading that team is chief executive officer Dr. Andrew Rosenstein, chief of the division of Gastroenterology at University of Maryland Saint Joseph Medical Center and assistant clinical professor of Gastroenterology and Hepatology at the University of Maryland Medical Center. Dr. Rosenstein has been recognized by Baltimore Magazine as a top doctor in the Baltimore area, according to a press release.

Dr. Andrew Rosenstein, CEO of Steep Hill Maryland, PA and D.C.

According to Dr. Rosenstein, they want to provide accurate clinical results for trials with patients using cannabis. “All clinical trials will require a competent, credible and reliable lab partner and that is what we are bringing to the field- and that is why we are working with Steep Hill,” says Dr. Rosenstein. With team members having backgrounds in pathology, molecular diagnostics, clinical chemistry, microbiology and genetics, it should come as no surprise that they plan to participate in clinical research.

Dr. Rosenstein’s vested interest in cannabis safety stems from prior experience with his patients using cannabis. “Over the past five years, we have seen an increased number of patients using cannabis, particularly for managing the side effects of Crohn’s disease and cancer treatment,” says Dr. Rosenstein. “They would bring it up to us and at the time I didn’t know much about it, but anecdotally it’s really clear that a lot of patients have great responses to it.” Not knowing much about the preparation or safety of cannabis at the time led Dr. Rosenstein to advise patients to be very careful if they are immunocompromised.

Examination of cannabis prior to testing- credit Steep Hill Labs, Inc. — Examination of cannabis prior to testing- credit: Steep Hill Labs, Inc.

“When a patient is immunocompromised, a bacterial or fungal infection can be lethal, so because we had patients using cannabis, we wanted to make sure it was safe,” says Dr. Rosenstein. So when Maryland legalized medical cannabis, Dr. Rosenstein and his team saw the need to protect patient safety and Steep Hill was a perfect fit. “We really didn’t want to reinvent the wheel so we looked for someone to partner with,” says Dr. Rosenstein. “Steep Hill has the best technology and the best credibility and we didn’t want to compromise on quality and safety issues. They felt the same way so we partnered with them and culturally it has been a great fit.”

Steep Hill Express in Berkeley, CA- MD,PA and D.C. will have a similar offering of instant potency analysis

The new laboratories plan to offer a similar range of services that are offered at other Steep Hill labs, such as rapid potency testing for THC-A, ∆-9-THC, CBD, CBD-A and moisture. But Dr. Rosenstein sees clinical opportunities in the East Coast medical hubs. “We want to provide the testing component for studies, providing clinical reproducibility and consistency, and those are the things as a top-notch lab that we are interested in doing.”

A petri dish of mold growth from tested cannabis- Photo credit: Steep Hill- — A petri dish of mold growth from tested cannabis- Photo credit: Steep Hill Labs, Inc.

With a physician-led group that has experience in molecular diagnostics, partnering with Steep Hill is about being medically focused, according to Dr. Rosenstein. “First and foremost, this is about patient safety.” Because of that, he emphasizes the need for required microbiological contaminant testing, particularly because of his experience with patients. “If you’re a cancer patient and you get a toxic dose of salmonella or E. coli, that can kill you, so testing for microbiologic contamination is of the highest priority.”

According to Warner, bridging the medical cannabis science gap with Steep Hill’s professionalism and experienced doctors practicing medicine is a big deal. “We are working very closely with their medical team to make sure these standards are medically superior,” says Warner. “To have these doctors with such a high level of knowledge in medicine working with us in cannabis analytics is a breakthrough.”

October 6, 2016

The Nerd Perspective

Detecting the Undetectable

By Amanda Rigdon

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In my last column, I took a refreshing step out of the weeds of the specifics behind cannabis analyses and took a broader, less technical look at the cannabis industry. I had envisioned The Nerd Perspective being filled with profound insights that I have had in the cannabis industry, but I have realized that if I restricted this column to insights most would consider profound…well…there would not be many articles. So in this article, I want to share an insight with you, but not one that is earth shattering. Instead, I want to talk about a simple concept in a way that might help you think a little differently about the results your lab generates, the results you have to pay for or even the results printed on a cannabis product you might purchase.

This article is all about the simple concept of concentration – the expression of how much of something there is in relation to something else. We use expressions of concentration all the time – calories per serving, percent alcohol in beer, even poll results in the presidential election circus. Cannabis is not excluded from our flippant use of concentration terms – percent cannabinoid content, parts-per-million (ppm) residual solvents, and parts-per-billion (ppb) pesticides. Most of us know the definition of percent, ppm, and ppb, and we use these terms all the time when discussing cannabis analytical methods. During my career in analytical chemistry, it has occurred to me that parts per billion is a really infinitesimal amount…I know that intellectually, but I have never tried to actually visualize it. So being the nerd that I am, I went about comparing these often-used concentration terms visually in my kitchen.

I started by preparing a 1% solution of food coloring paste in water. This was accomplished by weighing out 5g of the food coloring and dissolving it into 500mL of water (about one teaspoon into a pint). The resulting solution was so dark it was almost black:

The picture above expresses the low end of what we care about in terms of cannabinoid concentration and a pretty normal value for a high-concentration terpene in cannabis.

I then took one teaspoon of that mixture and dissolved it into 1.32 gallons of water (5mL into 5000mL), resulting in a 10ppm solution of green food coloring in water:

I did not expect the resulting solution to be so light colored given the almost-black starting solution, but I did dilute the solution one thousand times. To put this into perspective, 10ppm is well above many state regulatory levels for benzene in a cannabis concentrate.

I then took one teaspoon of the almost-colorless 10ppm solution and dissolved that into another 1.32 gallons of water, resulting in a very boring-looking 10ppb solution of green food coloring in water:

Obviously, since I diluted the almost-colorless 10ppm solution a thousand times, the green food coloring cannot be seen in the picture above. As a reference, 10ppb is on the low end of some regulations for pesticides in food matrices, including – possibly – cannabis. I know the above picture is not really very compelling, so let’s think in terms of mass. The picture above shows eleven pounds of water. That eleven pounds of water contains 50 micrograms of food coloring…the weight of a single grain of sand.

To expand on the mass idea, let’s take a look at the total mass of cannabis sold legally in Colorado in 2015 – all 251,469 pounds of it. To express just how staggeringly small the figure of 10ppb is, if we assume that all of that cannabis was contaminated with 10ppb of abamectin, the total mass of abamectin in that huge amount of cannabis would be just 1.143g – less than half the mass of a penny.

To me, that is an extremely compelling picture. The fact is there are instruments available that can measure such infinitesimal concentrations. What’s more, these tiny concentrations can be measured in the presence of relatively massive amounts of other compounds – cannabinoids, terpenes, sugars, fats – that are always present in any given cannabis sample. The point I’d like to make is that the accurate measurement of trace amounts of cannabis contaminants including pesticides and residual solvents is an astounding feat that borders on magical. This feat is not magic though. It requires extremely delicate instrumentation, ultra-pure reagents, expert analysts, and labor-intensive sample preparation. It is far from trivial, and unlike magic, requires a large investment on the part of the laboratories performing this feat of science. Other industries have embraced this reality, and the cannabis industry is well on its way toward that end…hopefully this article will help put the job of the cannabis analytical lab into perspective.

September 14, 2016

Automated Solutions for Cannabis Laboratories: Part I

By Danielle Mackowsky

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rsz_96_well_plate-1-1 — Using well plates for dSPE sorbents can help expedite sample clean up.

Sample volume remains to be the primary influence on whether an automated solution is a logical investment for a cannabis testing facility. Due to both the complexity of the material being tested and the extraction approach at hand, it may be difficult to find an automated platform that can fully accommodate your laboratory’s needs. Hamilton Robotics in collaboration with United Chemical Technologies (UCT) has developed a solution that allows for automation of specific sample clean up steps commonly utilized in cannabis pesticide testing schemes. The MPE² Positive Pressure Extraction/Evaporation Module is a standalone manifold that can also be incorporated into a number of automated liquid handling decks. Used in tandem with dispersive solid phase extraction (dSPE) salts/sorbents packed into a 96 well plate, this combination provides laboratories with high throughput extraction convenience with comparable results to traditional dSPE for the analysis of over forty pesticides.

As states continue to expand testing requirements for pesticides, it is vital that your laboratory is equipped with a method that allows versatility for the addition of new compounds without burdening your extraction team. There are a variety of dSPE salt and sorbent blends readily available that have been optimized for cannabis extractions. This allows for the use of a reliable extraction technique that can be adapted for the automation age. Hamilton is widely recognized throughout both clinical and forensic laboratory settings and the MPE² platform is an excellent first system for laboratories beginning to automate/semi-automate their processes.

MPE2 Positive Pressure Extraction/Evaporation Module

Following an initial QuEChERS extraction, additional cleanup is typically recommended for extracts that are being analyzed for pesticide content due to the low detection limits often required. dSPE provides the necessary sample clean up to obtain those thresholds, but often burdens a laboratory staff with additional time consuming preparation steps. Traditionally, dSPE salts are packed into 2 mL centrifugation tubes that require a cumbersome supernatant pipetting step followed by additional vortex, spin and transfer steps. By packing the dSPE sorbents into a well plate format, the user is able to completely automate this above described clean up ultimately saving time and adding convenience without jeopardizing any recovery data.

For most compounds, the recovery was greater than 65% for both methods of dSPE. The mean recoveries for traditional dSPE were 98.0%, 99.2% and 97.9% at pesticide concentrations of 50 ng/mL, 100 ng/mL and 200 ng/mL, respectively. For comparison, the mean recoveries at the same concentrations for well plate dSPE were 85.0%, 88.9% and 89.1%. Therefore, there was typically about a 10-11% absolute difference in recovery between the two methods, which can be corrected for by implementing the use of internal standards. When comparing the recovery differences between the two methods, there are six compounds with noticeably larger discrepancies across all three concentrations, namely: chlorpyrifos, cyprodinil, diazinon, spinetoram, spiromesifen 278 and trifloxystrobin. If these data sets are excluded, then the average absolute differences in recovery between the two methods decrease to 8.8%, 6.4% and 5.8% for concentrations of 50 ng/mL, 100 ng/mL and 200 ng/mL, respectively.

Overall, laboratories can estimate on saving 40-60 minutes per 96 samples processed using the Hamilton MPE² in conjunction with a UCT dSPE plate. When a liquid handling robot is also available, this time saving estimation is potentially doubled. Time spent per sample, including the training of laboratory scientists, is an important factor to consider when setting up your laboratory. Automation is in an investment that can greatly reduce a laboratory’s overall labor costs in the long run.

September 12, 2016

Oregon Cannabis Lab Accreditation Program Gets Help, Problems Addressed

By Aaron G. Biros

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Last week, news of problems facing Oregon’s cannabis laboratory accreditation program surfaced, leading some to speculate about possible delays for the recreational cannabis market. According to The Register-Guard, ORELAP administrator Gary Ward believed the program was “on the precipice of collapse.”

According to Jonathan Modie, spokesman for the Oregon Health Authority (OHA), the Oregon Environmental Laboratory Accreditation Program (ORELAP) was anticipating over 30 cannabis laboratories applying for accreditation and they doubled their staff from two to four to prepare for the uptick in applications.

In June, the agency had zero labs applying for accreditation but within two months, 37 labs applied. However, the Oregon Department of Environmental Quality (DEQ) just provided three additional staff members on Monday to help with the application process, says Modie.

Some believe the issues could mean the state may not have enough accredited labs by October 1^st, when the recreational cannabis market is expected to go into full swing. “It is difficult to say exactly how many labs we can accredit by October 1,” says Modie. “We have seven labs today which would bring it to nine labs waiting for assessment, but our goal is to get as many labs assessed and hopefully accredited as soon as possible.”

With the additional staff members, Modie is hopeful this will jumpstart the program. “We really appreciate our collaboration with the DEQ and look forward to boosting our capacity a bit to help us get through this busy time,” says Modie.

Part of the reason some laboratories might have trouble meeting prerequisites is simply because the requirements are very strict. “The process involves submitting a quality manual, standard operating procedures, method validation, submitting proficiency testing data and finally undergoing an ORELAP assessment by our staff, so it is a very rigorous process,” says Modie. “This speaks to our concern for making sure they have the right systems in place so public health is protected.” Modie said there were at least three labs that did not pass the assessment.

Roger Voelker, lab director at OG Analytical

Bethany Sherman, chief executive officer of OG Analytical, believes the hardest part of the process involves getting accredited for testing pesticides. OG Analytical, based in Eugene, Oregon, has already received their accreditation, one of the first to do so. “The pesticide testing requires our most expensive instrumentation and the sample preparation for testing pesticides is the most time consuming,” says Sherman. “Not only does it require very specific instrumentation, it also requires a real know-how and expertise to ensure we are cleaning samples appropriately, minimizing background noise and looking at the pesticides in trace quantities.” According to Sherman, laboratories are also left to their own devices to develop methodologies specifically for the cannabis matrix, adding to the difficulties.

Rodger Voelker, Ph.D., lab director at OG Analytical, seems confident that the state will be able to handle it. “It is a relief they were able to get some resources from the DEQ and I think the state will not allow a program with this kind of importance to fall apart,” says Voelker. He believes after this initial phase of putting the program in place, the workload will go down. “It is easier to maintain a program than it is to implement,“ adds Voelker. In his eyes, it is crucial for the program to require rigorous science. “People are forced to reconcile that there is a tremendous amount of controls to be considered to produce legally defensible data and I think it is great that the requirements are so strict.”

The OHA’s job is to essentially safeguard public health and they do not want to leave any stone unturned when it comes to potential contamination, says Modie. “This is not just about getting as many labs accredited as possible, this is about protecting public health.”

September 6, 2016

The Nerd Perspective

‘Instant’ Cannabis Potency Testing: Different Approaches from Different Manufacturers

By Amanda Rigdon

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This is the first piece of a regular column that CIJ has been so kind to allow me to write for their publication. Some readers might recognize my name from The Practical Chemist column in this publication. Since the inception of that column, I’ve finally taken the plunge into the cannabis industry as chief technical officer of Emerald Scientific. Unlike The Practical Chemist, I will not spend the entire first article introducing the column. The concept is simple: while I find the textbook-esque content of The Practical Chemist scintillating, I have a feeling that the content is a little too heavy to spring on someone who is looking for engaging articles over their precious coffee break. Instead, The Nerd Perspective will consist of less-technical writing focusing on my experience and insights for the cannabis industry as a whole. But don’t worry – I’m sure I will not be able to refrain from technical jargon altogether.

To kick off the column, I want to talk about instrumentation for ‘instant’ cannabis potency testing. At this point, it’s common knowledge in the cannabis analytics industry that the most accurate way to test cannabis potency is through extraction then analysis by HPLC-UV. I agree wholeheartedly with that sentiment, but HPLC analyses have one drawback: they can be either inexpensive or fast – not both. There are some instruments entering the market now that– while not as directly quantitative as HPLC-UV – promise to solve the inexpensive/fast conundrum. During my most recent trip to California, I was able to spend some quality time with two well-known instrument manufacturers: SRI Instruments and PerkinElmer, both of whom manufacture instruments that perform fast, inexpensive cannabis potency analyses. From my previous home at the heights of The Ivory Tower of Chromatography: Home of the Application Chemists, SRI and PE couldn’t be more different. But as seen through the eyes of a company who deals with a wide range of customers and analytical needs, it turns out that SRI and PE are much the same – not only in their open and honest support of the cannabis industry, but also in terms of their love of all things technical.

My first stop was SRI Instruments. They are a relatively small company located in an unassuming building in Torrance, CA. Only a few people work in that location, and I spent my time with Hugh Goldsmith (chief executive officer) and Greg Benedict (tech service guru). I have worked with these guys for a few years now, and since the beginning, I have lovingly referred to them as the MacGyvers of chromatography. Anyone familiar with SRI GCs knows that what they lack in aesthetics, they make up for in practicality – these instruments truly reflect Hugh and Greg’s character (that’s meant as a compliment).

SRI specializes in relatively inexpensive portable and semi-portable instruments that are easy to set up, easy to operate, and most importantly – engineered for a purpose. It’s actually really hard to manufacture an instrument that meets all three of these criteria, and the folks at SRI accomplish this with their passionate and unique approach to problem solving. What I love about these guys is that for them, nothing is impossible. Here’s an example: the price of the portable GC-FID instruments SRI builds is inflated because the instruments require separate – and pricey – hydrogen generators. That’s a big problem – hydrogen generators are all pretty much the same, and none of them are cheap. This didn’t faze SRI: they just decided to design their own super small on-board hydrogen generator capable of supplying hydrogen to a simple GC system for six hours with just 20mL of distilled water from the grocery store! I’m not kidding – I saw it in action on their new Model 420 GC (more on that in some future pieces). Was the final product pretty? Not in the least. Did it work? Absolutely. This kind of MacGyver-esque problem solving can only be done successfully with a deep understanding of the core principles behind the problem. What’s more, in order to engineer instruments like these, SRI has to have mastery over the core principles of not only chromatographic separation, but also of software development, electrical engineering, and mechanical engineering – just to name a few. These quirky, unassuming guys are smart. SRI is a company that’s been unapologetically true to themselves for decades; they’ll never be a contender for beauty queen, but they get the job done.

On the surface, PerkinElmer (PE) contrasts with SRI in almost every way possible. With revenue measured in billions of dollars and employees numbering in the thousands, PE is a behemoth that plays not only in the analytical chemistry industry but also in clinical diagnostics and other large industries. Where SRI instruments have a characteristic look of familiar homeliness, PE instruments are sleek and sexy. However, PerkinElmer and SRI are more alike than it would seem; just like the no-frills SRI, the hyper-technical PE instruments are engineered for a purpose by teams of very smart, passionate people.

With its modest price tag and manual sample introduction, the SRI Model 420 is engineered for lower throughput users to be a fast, simple, and inexpensive approach to semi-quantitative process control. The purpose of the instruments manufactured by PE is to produce the highest-quality quantitative results as quickly as possible for high-throughput labs. PE instruments are built using the best technology available in order to eke out every last ounce of quantitative accuracy and throughput possible. Fancy technology is rarely inexpensive, and neither is rigorous product development that can last years in some cases. In a way, PE is Doogie Howser to SRI’s MacGyver. Like MacGyver, Doogie is super smart, and his setting is a sterile hospital rather than a warzone.

I had a wonderful conversation with Tim Ruppel, PE’s headspace-GC specialist, on the sample introduction technology incorporated into the TurboMatrix Headspace Sampler, where I also learned that the basic technology for all PerkinElmer headspace-GC instruments was designed by the men who wrote The Book on headspace gas chromatography: Bruno Kolb and Leslie Ettre**. Later, I was able to get a much-needed lesson on FT-IR and the Spectrum Two IR Spectrometer from Brian Smith, PE’s spectroscopy expert, who actually wrote the book on quantitative spectroscopy***. Tim and Brian’s excitement over their technology mirrored that of Hugh and Greg. It turns out that SRI and PerkinElmer are more alike than I thought.

These two instrument manufacturers have addressed the fast/inexpensive conundrum of cannabis potency testing in two different ways: SRI’s instrument is extremely inexpensive, easy to operate, and will provide semi-quantitative values for THC, CBD, and CBN in just a few minutes; PE’s instrument is more expensive up front, but provides quantitative (though not directly quantitative) values for all of the major cannabinoids almost instantly, and requires almost no maintenance or consumables. These two instruments were designed for specific uses: one for inexpensive, easy use, and the other for more comprehensive results with a higher initial investment. The question consumers have to ask themselves is “Who do I need to solve my problem?” For some, the answer will be MacGyver, and for others, Doogie Howser will provide the solution – after all, both are heroes.

** B. Kolb, L. Ettre, Static Headspace-Gas Chromatography: Theory and Practice, John Wiley & Sons, Hoboken, NJ, 2006.

*** Brian C. Smith, Quantitative Spectroscopy: Theory and Practice, Elsevier, Boston, MA, 2002.

September 6, 2016

Quality From Canada

The Devil is in the Detail – Changes to Canada’s Cannabis Regs to Encourage Patient Independence and Business Competition

By Tegan Adams, Elfi Daniel-Ivad MSc

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Canada’s new ACMPR was launched late last month on August 24^th. The key change that most notice is that Canadians may now again grow their own cannabis at home for medical purposes. In addition, more strict guidelines for product testing and labeling requirements for Licensed Producers (LPs) were released.

Short term pain for long term gain. While the combination of allowing patients to grow at home and more strict regulations for LPs may at first seem like a business disadvantage; overtime LPs will be thankful for the combination switch. Health Canada’s new requirements encourage a leveling of the playing field globally between LPs and large scale product manufacturers of pharmaceuticals, therapeutics and natural health products. The steps Health Canada is taking to regulate our producers, is exactly what they need to get ready for mass production that will be necessary for recreational markets, scheduled for release in Spring 2017.

Picture rows of Tylenol bottles on the shelf at your favorite pharmacy. Now picture rows of cannabis bottles on the shelf beside them. This is what medical cannabis will look like in Canada perhaps as early as 2018, if not sooner. With just under forty LPs on the map and a projected sales volume of modest billions, Canada’s LPs’ eyes are widening with dollar signs as they lube up their oil production and more to see what shelves in Canada will hold.

Curious to know more? Our regulatory department manager Elfi Daniel-Ivad is an expert in regulatory change. She has worked on close to 150 submissions for cannabis licensees in Canada and beyond. Here are a few key changes from her department’s overview to better understand.

MMPR	ACMPR (Updated)
No personal production or designated production available to patients (aside from that grandfathered in by MMAR).	Personal production and designated production available. Patients may grow 5 indoor plants OR 2 outdoor plants at any given time per gram prescribed to them.
Licensed Producers were not required to label THC or CBD amounts in dried cannabis, though most producers did for sales and educational purposes. Oils had to be labeled with THC and CBD amounts.	Licensed Producers must label their percent THC and CBD for dried and fresh cannabis products.
For the labelling of oils, the total quantity of THC, CBD and oil in a container had to be shown. Restrictions on THC allowed no more than 10mg/mL THC per capsule and no more than 30mg/mL THC per mL oil to be distributed.	In addition, oil labels must now include information on “carrier” oil and allergen information. Containers must be labelled with number of capsules, the net weight and volume of each capsule. .
No reference to validation of analytical testing methods.	Analytical testing must be completed using validated testing methods; confirming reliability and consistency in results for contaminants, disintegration, residues and THC, THC-A, CBD and CBD-A
Accredited labs can only test products as received from Licensed Producers.	In addition to Licensed Producers, patients growing their own or having a designated grower growing for them may also test their products at an accredited lab.

In addition to these changes, it is important to note that if an individual or company has an MMPR proposal already submitted they can now revise it to include oil production (previously, it was first dried bud only). If a company submits a new ACMPR proposal, they can include oil production on their application right away. Interested in submitting your own application? Or need help with one in the USA? Our regulatory department would be happy to answer any questions you might have about the process.

August 24, 2016

The Practical Chemist

Building the Foundation of Medical Cannabis Testing – Understanding the Use of Standards and Reference Materials – Part 1

By Joe Konschnik

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In previous articles, you may recall that Amanda Rigdon, one our contributing authors, stated that instrument calibration is the foundation of all data quality. In this article, I would like to expand on that salient point. A properly calibrated instrument will, in fact, produce reliable data. It is the foundation we build our data upon. All foundations are comprised of building blocks, and our laboratory is no exception. If we take this analogy further, the keystone to the laboratory foundation, the stone that all data relies upon, is the analytical reference material. Proper calibration means that it is based on a true, accurate value. That is what the reference material provides. In this article, I would like to expand on the use and types of reference materials in analytical testing.

To develop sound analytical data, it is important to understand the significance of reference materials and how they are properly used. The proper selection and use of reference materials ensures the analytical certainty, traceability and comparability necessary to produce scientifically sound data. First, let’s take a moment to define the types of commonly used reference materials. According to the International Vocabulary of Metrology (VIM), a Reference Standard (RS) is something that is reused to measure against, like a balance or a set of weights. A Reference Material (RM) is a generic term. It is described as something that is prepared using a RS that is homogeneous, stable and is consumed during its use for measurement. An example of an RM is the solutions used to construct a calibration curve, often referred to as calibration standards, on your GC or LC. Due to the current state of cannabis testing, reference materials can be hard to find and, even more critical, variable in their accuracy to a known reference standard. Sometimes this is not critical, but when quantifying an unknown, it is paramount.

RMs can be either quantitative or qualitative. Qualitative RMs verify the identity and purity of a compound. Quantitative RMs, on the other hand, provide a known concentration, or mass, telling us not only what is present, and its purity, but also how much. This is typically documented on the certificate that accompanies the reference material, which is provided by the producer or manufacturer. The certificate describes all of the properties of the starting materials and steps taken to prepare the RM. For testing requirements, like potency, pesticides, etc., where quantitation is expected, it is important to use properly certified quantitative RMs.

Now, the pinnacle of reference materials is the Certified Reference Material (CRM). VIM defines a Certified Reference Material (CRM) as an RM accompanied by documentation issued by an authoritative body and provides one or more specified property values, with associated uncertainties and traceability using valid procedures. A CRM is generally recognized as providing the highest level of traceability and accuracy to a measurement – the strongest keystone you can get for your foundation. It is also important to recognize that the existence of a certificate does not make a reference material a CRM. It is the process used in manufacturing that makes it a CRM, and these are typically accreditations earned by specific manufacturers who have invested on this level of detail.

Now that we understand the types of reference materials we can choose, in the next article of this series we will describe what a CRM provider must do to ensure the material and how we can use them to develop reliable data. Without properly formulated and prepared CRMs, instrument calibration and the use of internal standards are less effective at ensuring the quality of your data.

If you have any questions please contact me, Joe Konschnik at (800) 356-1688 ext. 2002 by phone, or email me at joe.konschnik@restek.com.

June 29, 2016

The Practical Chemist

Internal Standards– Turning Good Data Into Great Data

By Amanda Rigdon

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Everyone likes to have a safety net, and scientists are no different. This month I will be discussing internal standards and how we can use them not only to improve the quality of our data, but also give us some ‘wiggle room’ when it comes to variation in sample preparation. Internal standards are widely used in every type of chromatographic analysis, so it is not surprising that their use also applies to common cannabis analyses. In my last article, I wrapped up our discussion of calibration and why it is absolutely necessary for generating valid data. If our calibration is not valid, then the label information that the cannabis consumer sees will not be valid either. These consumers are making decisions based on that data, and for the medical cannabis patient, valid data is absolutely critical. Internal standards work with calibration curves to further improve data quality, and luckily it is very easy to use them.

So what are internal standards? In a nutshell, they are non-analyte compounds used to compensate for method variations. An internal standard can be added either at the very beginning of our process to compensate for variations in sample prep and instrument variation, or at the very end to compensate only for instrument variation. Internal standards are also called ‘surrogates’, in some cases, however, for the purposes of this article, I will simply use the term ‘internal standard.’

Now that we know what internal standards are, lets look at how to use them. We use an internal standard by adding it to all samples, blanks, and calibrators at the same known concentration. By doing this, we now have a single reference concentration for all response values produced by our instrument. We can use this reference concentration to normalize variations in sample preparation and instrument response. This becomes very important for cannabis pesticide analyses that involve lots of sample prep and MS detectors. Figure 1 shows a calibration curve plotted as we saw in the last article (blue diamonds), as well as the response for an internal standard added to each calibrator at a level of 200ppm (green circles). Additionally, we have three sample results (red triangles) plotted against the calibration curve with their own internal standard responses (green Xs).

Figure 1: Calibration Curve with Internal Standard Responses and Three Sample Results

In this case, our calibration curve is beautiful and passes all of the criteria we discussed in the previous article. Lets assume that the results we calculate for our samples are valid – 41ppm, 303ppm, and 14ppm. Additionally, we can see that the responses for our internal standards make a flat line across the calibration range because they are present at the same concentration in each sample and calibrator. This illustrates what to expect when all of our calibrators and samples were prepared correctly and the instrument performed as expected. But lets assume we’re having one of those days where everything goes wrong, such as:

We unknowingly added only half the volume required for cleanup for one of the samples
The autosampler on the instrument was having problems and injected the incorrect amount for the other two samples

Figure 2 shows what our data would look like on our bad day.

Figure 2: Calibration Curve with Internal Standard Responses and Three Sample Results after Method Errors

We experienced no problems with our calibration curve (which is common when using solvent standard curves), therefore based on what we’ve learned so far, we would simply move on and calculate our sample results. The sample results this time are quite different: 26ppm, 120ppm, and 19ppm. What if these results are for a pesticide with a regulatory cutoff of 200ppm? When measured accurately, the concentration of sample 2 is 303ppm. In this example, we may have unknowingly passed a contaminated product on to consumers.

In the first two examples, we haven’t been using our internal standard – we’ve only been plotting its response. In order to use the internal standard, we need to change our calibration method. Instead of plotting the response of our analyte of interest versus its concentration, we plot our response ratio (analyte response/internal standard response) versus our concentration ratio (analyte concentration/internal standard concentration). Table 1 shows the analyte and internal standard response values for our calibrators and samples from Figure 2.

Table 1: Values for Calibration Curve and Samples Using Internal Standard

The values highlighted in green are what we will use to build our calibration curve, and the values in blue are what we will use to calculate our sample concentration. Figure 3 shows what the resulting calibration curve and sample points will look like using an internal standard.

Figure 3: Calibration Curve and Sample Results Calculated Using Internal Standard Correction

We can see that our axes have changed for our calibration curve, so the results that we calculate from the curve will be in terms of concentration ratio. We calculate these results the same way we did in the previous article, but instead of concentrations, we end up with concentration ratios. To calculate the sample concentration, simply multiply by the internal standard amount (200ppm). Figure 4 shows an example calculation for our lowest concentration sample.

Figure 4: Example Calculation for Sample Results for Internal-Standard Corrected Curve

Using the calculation shown in Figure 4, our sample results come out to be 41ppm, 302ppm, and 14ppm, which are accurate based on the example in Figure 1. Our internal standards have corrected the variation in our method because they are subjected to that same variation.

As always, there’s a lot more I can talk about on this topic, but I hope this was a good introduction to the use of internal standards. I’ve listed couple of resources below with some good information on the use of internal standards. If you have any questions on this topic, please feel free to contact me at amanda.rigdon@restek.com.

Resources:

When to use an internal standard: http://www.chromatographyonline.com/when-should-internal-standard-be-used-0

Choosing an internal standard: http://blog.restek.com/?p=17050

June 2, 2016

A2LA, Americans for Safe Access Announce Cannabis-Specific Lab Accreditation

By Aaron G. Biros

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The American Association for Laboratory Accreditation (A2LA) and Americans for Safe Access (ASA) announced yesterday a collaboration to develop a cannabis-specific laboratory accreditation program based upon the requirements of ISO/IEC 17025 and ASA’ s Patient Focused Certification (PFC) Program. Accreditation under this program will offer the highest level of recognition and provide the most value to the laboratory and users of the products tested, according to a press release published yesterday. ASA is the largest medical cannabis patient advocacy group in the United States. “A2LA is pleased to partner with ASA to offer a cannabis testing laboratory accreditation program to ISO/IEC 17025 as well as the additional laboratory requirements from ASA’s Patient Focused Certification Program,” says Roger Brauninger, biosafety program manager at A2LA.

PFC-A2LA — Pictured left to right: Kristin Nevedal, Program Manager, PFC at ASA;
Jahan Marcu, Ph.D Chief Scientist, PFC at ASA;
Roger Brauninger, BioSafety Program Manager, A2LA;
Michelle Bradac, Senior Accreditation Officer, A2LA

The program affirms that cannabis laboratories are compliant with state and local regulations and ensures that they adhere to the same standards that are followed by laboratories used and inspected by the Environmental Protection Agency (EPA), the United States Department of Agriculture (USDA), and the U.S. Consumer Product Safety Commission (CPSC) among other regulatory bodies. The two non-profit organizations will offer their first joint training course at A2LA’s headquarters in Maryland from July 11^th to the 15^th. During this course, participants will receive training on PFC’s national standards for the cultivation, manufacture, dispensing, and testing of cannabis and cannabis products, combined with ISO/IEC 17025 training.

The guidelines for cannabis operations that serve as the basis for this accreditation program were issued by the American Herbal Products Association (AHPA) Cannabis Committee, an industry stakeholder panel, and have already been adopted by sixteen states. “We are very excited to see the PFC program join the ISO/IEC 17025 accreditation efforts to help fully establish a robust and reliable cannabis testing foundation,” says Jeffrey Raber, chief executive officer of The Werc Shop, a PFC-certified cannabis testing laboratory. “It is a great testament to ASA’s commitment to quality in their PFC program by partnering with a world-renowned accrediting body to set a new standard for cannabis testing labs.”

According to Kristin Nevedal, program director of PFC, this is an important first in the industry. “This new, comprehensive accreditation program affirms laboratory operations are meeting existing standards and best practices, adhering to the ISO/IEC 17025 criteria, and are compliant with state and local regulations,” says Nevedal. “This program is the first of its kind developed specifically for the cannabis industry, giving confidence to patients as well as regulators that their test results on these products are accurate and consistent.”

“The program will combine the expertise and resources of the country’s largest accreditation body with the scientific rigor and knowledge base of the nation’s largest medical cannabis advocacy group, benefitting the myriad of laboratories tasked with analyzing cannabis products,” says Nevedal. According to Brauninger, a cannabis-specific accreditation program is vital to the industry’s constantly shifting needs. “The ability to now offer a cannabis testing laboratory accreditation program that is tailored to address the unique concerns and issues of the industry will help to add the necessary confidence and trust in the reliability and safety of the cannabis products on the market,” says Brauninger. “Those laboratories that gain accreditation under this program will be demonstrating that they adhere to the most comprehensive and relevant set of criteria by their compliance to both the underlying framework of the internationally recognized ISO/IEC 17025:2005 quality management system standard and the specific guidelines issued by the AHPA Cannabis Committee.” This type of collaboration could represent a milestone in progress toward achieving a higher level of consumer safety in the cannabis industry.

June 1, 2016

The Practical Chemist

Calibration Part II – Evaluating Your Curves

By Amanda Rigdon

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Despite the title, this article is not about weight loss – it is about generating valid analytical data for quantitative analyses. In the last installment of The Practical Chemist, I introduced instrument calibration and covered a few ways we can calibrate our instruments. Just because we have run several standards across a range of concentrations and plotted a curve using the resulting data, it does not mean our curve accurately represents our instrument’s response across that concentration range. In order to be able to claim that our calibration curve accurately represents our instrument response, we have to take a look at a couple of quality indicators for our curve data:

correlation coefficient (r) or coefficient of determination (r²)
back-calculated accuracy (reported as % error)

The r or r² values that accompany our calibration curve are measurements of how closely our curve matches the data we have generated. The closer the values are to 1.00, the more accurately our curve represents our detector response. Generally, r values ≥0.995 and r² values ≥ 0.990 are considered ‘good’. Figure 1 shows a few representative curves, their associated data, and r² values (concentration and response units are arbitrary).

Figure 1: Representative Curves and r2 values

Let’s take a closer look at these curves:

Curve A: This represents a case where the curve perfectly matches the instrument data, meaning our calculated unknown values will be accurate across the entire calibration range.

Curve B: The r² value is good and visually the curve matches most of the data points pretty well. However, if we look at our two highest calibration points, we can see that they do not match the trend for the rest of the data; the response values should be closer to 1250 and 2500. The fact that they are much lower than they should be could indicate that we are starting to overload our detector at higher calibration levels; we are putting more mass of analyte into the detector than it can reliably detect. This is a common problem when dealing with concentrated samples, so it can occur especially for potency analyses.

Curve C: We can see that although our r² value is still okay, we are not detecting analytes as we should at the low end of our curve. In fact, at our lowest calibration level, the instrument is not detecting anything at all (0 response at the lowest point). This is a common problem with residual solvent and pesticide analyses where detection levels for some compounds like benzene are very low.

Curve D: It is a perfect example of our curve not representing our instrument response at all. A curve like this indicates a possible problem with the instrument or sample preparation.

So even if our curve looks good, we could be generating inaccurate results for some samples. This brings us to another measure of curve fitness: back-calculated accuracy (expressed as % error). This is an easy way to determine how accurate your results will be without performing a single additional run.

Back-calculated accuracy simply plugs the area values we obtained from our calibrators back into the calibration curve to see how well our curve will calculate these values in relation to the known value. We can do this by reprocessing our calibrators as unknowns or by hand. As an example, let’s back-calculate the concentration of our 500 level calibrator from Curve B. The formula for that curve is: y = 3.543x + 52.805. If we plug 1800 in for y and solve for x, we end up with a calculated concentration of 493. To calculate the error of our calculated value versus the true value, we can use the equation: % Error = [(calculated value – true value)/true value] * 100. This gives us a % error of -1.4%. Acceptable % error values are usually ±15 – 20% depending on analysis type. Let’s see what the % error values are for the curves shown in Figure 1.

Table 1: % Error for Back-Calculated Values for Curves A – D

Our % error values have told us what our r² values could not. We knew Curve D was unacceptable, but now we can see that Curves B and C will yield inaccurate results for all but the highest levels of analyte – even though the results were skewed at opposite ends of the curves.

There are many more details regarding generating calibration curves and measuring their quality that I did not have room to mention here. Hopefully, these two articles have given you some tools to use in your lab to quickly and easily improve the quality of your data. If you would like to learn more about this topic or have any questions, please don’t hesitate to contact me at amanda.rigdon@restek.com.