Tag Archives: concentration

Analytical Instruments You Need to Start a Cannabis Testing Laboratory

By Bob Clifford
2 Comments

The cannabis industry is growing exponentially, and the use of cannabis for medical purposes is being adopted across the nation. With this boom in cannabis consumers, there has been an increasing need for knowledge about the product.

The role of testing labs has become crucial to the process, which makes owning and operating a lab more lucrative. Scientists testing for potency, heavy metals, pesticides, residual solvents, moisture, terpene profile, microbial and fungal growth, and mycotoxins/aflatoxins are able to make meaningful contributions to the medical industry by making sure products are safe, while simultaneously generating profits and a return on investment.

Here are the key testing instruments you need to conduct these critical analyses. Note that cannabis analytical testing requirements may vary by state, so be sure to check the regulations applicable to the location of your laboratory.

Potency Testing

High-performance liquid chromatograph (HPLC) designed for quantitative determination of cannabinoid content.

The most important component of cannabis testing is the analysis of cannabinoid profiles, also known as potency. Cannabis plants naturally produce cannabinoids that determine the overall effect and strength of the cultivar, which is also referred to as the strain. There are many different cannabinoids that all have distinct medicinal effects. However, most states only require testing and reporting for the dry weight percentages of delta-9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD). It should be noted that delta-9-tetrahydrocannabinolic acid (Δ9-THCA) can be converted to THC through oxidation with heat or light.

For potency testing, traditional high-performance liquid chromatography (HPLC) is recommended and has become the gold standard for analyzing cannabinoid profiles. Look for a turnkey HPLC analyzer that delivers a comprehensive package that integrates instrument hardware, software, consumables and proven HPLC methods.

Heavy Metal Testing

ICP-MS instrument for detecting heavy metals in cannabis.

Different types of metals can be found in soils and fertilizers, and as cannabis plants grow, they tend to draw in these metals from the soil. Heavy metals are a group of metals considered to be toxic, and the most common include lead, cadmium, arsenic and mercury. Most labs are required to test and confirm that samples are under the allowable toxic concentration limits for these four hazardous metals.

Heavy metal testing is performed by inductively coupled plasma mass spectrometry (ICP-MS). ICP-MS uses the different masses of each element to determine which elements are present within a sample and at what concentrations. Make sure to include accompanying software that provides assistant functions to simplify analysis by developing analytical methods and automatically diagnosing spectral interference. This will provide easy operation and analytical results with exceptionally high reliability.

To reduce running costs, look for a supporting hardware system that reduces the consumption of argon gas and electricity. For example, use a plasma ignition sequence that is optimized for lower-purity argon gas (i.e., 99.9% argon as opposed to more expensive 99.9999%).

Pesticide Testing

The detection of pesticides in cannabis can be a challenge. There are many pesticides that are used in commercial cannabis grow operations to kill the pests that thrive on the plants and in greenhouses. These chemicals are toxic to humans, so confirming their absence from cannabis products is crucial. The number of pesticides that must be tested for varies from state to state, with Colorado requiring only 13 pesticides, whereas Oregon and California require 59 and 66 respectively. Canada has taken it a step further and must test for 96 pesticides, while AOAC International is developing methods for testing for 104 pesticides. The list of pesticides will continue to evolve as the industry evolves.

Testing for pesticides is one of the more problematic analyses, possibly resulting in the need for two different instruments depending on the state’s requirements. For a majority of pesticides, liquid chromatography mass spectrometry (LCMS) is acceptable and operates much like HPLC but utilizes a different detector and sample preparation.

With excellent sensitivity and ultra-low detection limits, LC-MS/MS is an ideal technique for the analysis of pesticides.

Pesticides that do not ionize well in an LCMS source require the use of a gas chromatography mass spectrometry (GCMS) instrument. The principles of HPLC still apply – you inject a sample, separate it on a column and detect with a detector. However, in this case, a gas (typically helium) is used to carry the sample.

Look for a LC-MS/MS system or HPLC system with a triple quadrupole mass spectrometer that provides ultra-low detection limits, high sensitivity and efficient throughput. Advanced systems can analyze more than 200 pesticides in 12 minutes.

For GCMS analysis, consider an instrument that utilizes a triple quadrupole mass spectrometer to help maximize the capabilities of your laboratory. Select an instrument that is designed with enhanced functionality, analysis software, databases and a sample introduction system. Also include a headspace autosampler, which can also be used for terpene profiles and residual solvent testing.

Residual Solvent Testing

Residual solvents are chemicals left over from the process of extracting cannabinoids and terpenes from the cannabis plant. Common solvents for such extractions include ethanol, butane, propane and hexane. These solvents are evaporated to prepare high-concentration oils and waxes. However, it is sometimes necessary to use large quantities of solvent in order to increase extraction efficiency and to achieve higher levels of purity. Since these solvents are not safe for human consumption, most states require labs to verify that all traces of the substances have been removed.

Testing for residual solvents requires gas chromatography (GC). For this process, a small amount of extract is put into a vial and heated to mimic the natural evaporation process. The amount of solvent that is evaporated from the sample and into the air is referred to as the “headspace.” The headspace is then extracted with a syringe and placed in the injection port of the GC. This technique is called full-evaporated technique (FET) and utilizes the headspace autosampler for the GC.

Look for a GCMS instrument with a headspace autosampler, which can also be used for pesticide and terpene analysis.

Terpene Profile Testing

Terpenes are produced in the trichomes of the cannabis leaves, where THC is created, and are common constituents of the plant’s distinctive flavor and aroma. Terpenes also act as essential medicinal hydrocarbon building blocks, influencing the overall homeopathic and therapeutic effect of the product. The characterization of terpenes and their synergistic effect with cannabinoids are key for identifying the correct cannabis treatment plan for patients with pain, anxiety, epilepsy, depression, cancer and other illnesses. This test is not required by most states, but it is recommended.

The instrumentation that is used for analyzing terpene profiles is a GCMS with headspace autosampler with an appropriate spectral library. Since residual solvent testing is an analysis required by most states, all of the instrumentation required for terpene profiling will already be in your lab.

As with residual solvent testing, look for a GCMS instrument with a headspace autosampler (see above). 

Microbe, Fungus and Mycotoxin Testing

Most states mandate that cannabis testing labs analyze samples for any fungal or microbial growth resulting from production or handling, as well as for mycotoxins, which are toxins produced by fungi. With the potential to become lethal, continuous exposure to mycotoxins can lead to a buildup of progressively worse allergic reactions.

LCMS should be used to qualify and identify strains of mycotoxins. However, determining the amount of microorganisms present is another challenge. That testing can be done using enzyme linked immunosorbent assay (ELISA), quantitative polymerase chain reaction (qPCR) or matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), with each having their advantages and disadvantages.

For mycotoxin analysis, select a high-sensitivity LC-MS/MS instrument. In addition to standard LC, using an MS/MS selective detector enables labs to obtain limits of detection up to 1000 times greater than conventional LC-UV instruments.

For qPCR and its associated needs, look for a real-time PCR amplification system that combines thermal cyclers with optical reaction modules for singleplex and multiplex detection of fluorophores. These real-time PCR detection systems range from economical two-target detection to sophisticated five-target or more detection systems. The real-time detection platform should offer reliable gradient-enabled thermal cyclers for rapid assay optimization. Accompanying software built to work with the system simplifies plate setup, data collection, data analysis and data visualization of real-time PCR results.

Moisture Content and Water Activity Testing

Moisture content testing is required in some states. Moisture can be extremely detrimental to the quality of stored cannabis products. Dried cannabis typically has a moisture content of 5% to 12%. A moisture content above 12% in dried cannabis is prone to fungal growth (mold). As medical users may be immune deficient and vulnerable to the effects of mold, constant monitoring of moisture is needed. Below a 5% moisture content, the cannabis will turn to a dust-like texture.

The best way to analyze the moisture content of any product is using the thermogravimetric method with a moisture balance instrument. This process involves placing the sample of cannabis into the sample chamber and taking an initial reading. Then the moisture balance instrument heats up until all the moisture has been evaporated out of the sample. A final reading is then taken to determine the percent weight of moisture that was contained in the original sample.

A moisture balance can provide accurate determination of moisture content in cannabis.

Look for a moisture balance that offers intuitive operation and quick, accurate determination of moisture content. The pan should be spacious enough to allow large samples to be spread thinly. The halogen heater and reflector plate should combine to enable precise, uniform heating. Advanced features can include preset, modifiable measurement modes like automated ending, timed ending, rapid drying, slow drying and step drying.

Another method for preventing mold is monitoring water activity (aW). Very simply, moisture content is the total amount of water available, while water activity is the “free water” that could produce mold. Water activityranges from 0 to 1. Pure water would have an aW of 1.0. ASTM methods D8196-18 and D8297-18 are methods for monitoring water activity in dry cannabis flower. The aW range recommended for storage is 0.55 to 0.65. Some states recommend moisture content to be monitored, other states monitor water activity, and some states such as California recommend monitoring both.

Final Thoughts

As you can see, cannabis growers benefit tremendously from cannabis testing. Whether meeting state requirements or certifying a product, laboratory testing reduces growers’ risk and ensures delivery of a quality product. As medicinal and recreational cannabis markets continue to grow, analytical testing will ensure that consumers are receiving accurately

labeled products that are free from contamination. That’s why it is important to invest in the future of your cannabis testing lab by selecting the right analytical equipment at the start of your venture.

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:

rsz_percent2

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:

rsz_ppm

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:

rsz_1ppb

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.

Colorado Rule Changes Increase Costs for Edibles Producers

By Aaron G. Biros
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Cannabis processors and dispensaries in Colorado were hit with new rule changes over the weekend, going into effect on October 1st. The rule changes affect those producing edibles and dispensaries that sell retail and medical cannabis products.

The universal symbol required on all cannabis products in Colorado
The universal symbol required on all cannabis products in Colorado

As of October 1st, all cannabis edibles must be marked with the universal THC symbol, according to a bulletin posted by the Colorado Department of Revenue’s Marijuana Enforcement Division (MED). Both medical and retail cannabis products require labeling that includes a potency statement and a contaminant testing statement.

The rules also set “sales equivalency requirements” which essentially means a resident or non-resident at least 21 years of age can purchase up to one ounce of cannabis flower or up to 80 ten-milligram servings of THC or 8 grams of concentrate, according to the MED. The packaging must also include: “Contains Marijuana. Keep out of the reach of children.”

The universal symbol printed on products from Love's Oven.
The universal symbol printed on products from Love’s Oven.

It seems that cannabis edible manufacturers have two clear choices for complying with the new rule requiring the THC symbol: They can use a mold to imprint the symbol on their product or they can use edible ink. Peggy Moore, board chair of the Cannabis Business Alliance and owner of Love’s Oven, a Denver-based manufacturer of cannabis baked goods, uses edible ink to mark each individual serving. The printer uses similar technology and ink used to print on m&m’s, according to Moore. “Baked goods are difficult to find a solution for marking them because they are a porous product, not smooth.” Complying with the new rules almost certainly means added costs for processors and edibles producers.

Moore said she updated all of their labels to include the appropriate information in compliance with the rules. “In terms of regulatory compliance, there have been some disparities for labeling and testing requirements between medical and retail cannabis products, however they are coming into alignment now,” says Moore. “The testing statement rule has been in place for some time on the retail side, but now we are seeing this aligned with both medical and retail markets.” This new rule change could be seen as a baby step in making the different markets’ regulations more consistent.

jMackaypic
BEST Extractions

Defining BEST Extraction

By John A. Mackay, Ph. D.
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jMackaypic

Over the next few months, I would like to walk through a series of articles to cover the number of ways to extract potentially pharmaceutically active compounds from cannabis plants. However, in the first article I would like to review concerns being addressed in state regulations: contamination in concentrates with pesticides, mycotoxins, and residual solvents. The next article will cover the most common extraction with two different modes: CO2 versus hydrocarbons.

Currently, there is a lot of focus on the cannabis strain of hemp. This is defined as having less than 0.3% of THC, (the psychoactive compound). To be clear, the science of extraction is eons old, but the current revitalization is due to new scientific inquiry regarding the applications of the cannabis plant.

I am often asked, “What is the ‘best’ extraction for a natural product?” The BEST extraction? The key to this answer is that you must assume unintended consequences until you can prove that they are at least minimized compared to the intended consequences.

I have a suggestion for you to consider and I look forward to your response to it. I also assume the right to adapt and revise it.

Botanical integrity from seed to shelf

Efficacy of the process beyond efficiency, economics, effectiveness

Safety of people and product

Testing for confirmation at each step of process

The hemp industry has changed significantly over the past few years. Just casually flipping through the channels on television, reading a newspaper or magazine, (on any topic – news, business, sports, food and science) and there is some facet of hemp’s value being examined. The reduction of traditional pulmonary intake (smoking) in the legal marketplace can be tracked by sales of these products in the states where it is legal. The balance of ingestion is drastically tipping toward what might still be considered smoking with vaporizer products as well as toward edible consumables. The ingredients in these products come not from just adding the plant to the formulation, but rather a concentrated mixture. This is the difference between adding a raw vanilla and a teaspoon of vanilla extract. The compound getting the most coverage is cannabidiol (CBD), which is the compound derived from cannabidiolic acid (CBDA). The effects of the other compounds in the plant are being studied as well.

Unintended consequences from the concentration – extraction – are something we need to consider seriously as consumers. The labeled use of “natural” is one that is critical, but can be totally nullified by the unintended contamination in the extraction workflow. Years of making sure the hemp adheres to strict growing environment can be destroyed in seconds with the addition of polycyclic aromatic hydrocarbons (PAH’s) by the use of solvent that has these toxic chemicals in them. These come not through intended consequences, but not knowing the stabilizers and other additives in material being added to these previously pure plants.

What if I pour sour milk on a natural granola for breakfast? What if I use water with high lead or contaminated water to pour over natural coffee grind? Not a great way to start the day, but it is no different than using the most premium hemp and unknowingly adding low grade solvents or adding components from cleaning the surfaces of instruments that come in contact with hemp.

Note that, by definition, we are concentrating the material from the hemp plant. From 4,000 grams, we are getting 400 grams of CBDA if it is 10% by weight (and later converted to CBD). That compound is 10 times more concentrated in a solution. What other compounds are now also 10 times or 5 times or 100 times more concentrated? Maybe no “bad” ones, but how do you know that something else is not also in the mixture?

figure1 extract
Figure 1. With each step of concentration of the green balls, so it could be with other components in the mixture.

This is illustrated in the filtering of green balls in Figure 1. As the green balls become a greater and greater percentage of the solution, it is possible that other compounds like pesticides are also increasing in percentage of the extraction solution. The solution is more concentrated and “simpler” versus all of the other things in the original mixture.

The simple answer is in the testing of the components. The labeling of major compounds is only the beginning of what is on the label that you read. Heavy metals? PAH’s? Residual solvents? Pesticides? Molds? And a long list of other material that could come into the process after the plant left its pristine organic farm. Many studies can be read about slip agents in bags, contamination from workers in the workflow, and other sources of inconsistency.

There are a significant number of companies that I have seen that take this very seriously. New companies are being formed that have safety of product at the top of the list of importance. They are building facilities that are sterile and putting standard operating procedures in place that continually test the product along every step to ensure that they are in compliance.

ecxtractionfig2
Figure 2. Science and economics merge when considering all the possible uses of concentrated compounds to final product formulations

Supercritical fluid extraction is GRAS (generally regarded as safe). It is, only as long as the solvent specifications are known, the vendor meets those standards, and the instrument surfaces meet any necessary standards.

Supercritical carbon dioxide is used to clean surfaces of electronics and bones for skin grafts. It is used for the decaffeination of coffee as well as pulling trace amounts of pesticides from soil. It is used to extract antioxidants from krill and the active ingredients from algae as well as oil from core samples deep below the earth. It also extracts the terpenes and CBDA from hemp – as well as possibly anything that has been added to it.

The key take away from this article is to know the BEST extraction.

Botanical integrity from seed to shelf

Efficacy of the process beyond efficiency, economics, effectiveness

Safety of people and product

Testing for confirmation

Taking each of these into consideration will bring the best results for concentrations of hemp products. I hope you can extract the best from your day.