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Dr. Ed Askew
From The Lab

Quality Plans for Lab Services: Managing Risks as a Grower, Processor or Dispensary, Part 4

By Dr. Edward F. Askew
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Dr. Ed Askew

In the last three articles, I discussed the laboratory’s responses or defenses used to reply to your questions about laboratory results that place stress on the success of your business. The Quality Control (QC) results can cause this stress if they are not run correctly to answer the following questions:

  1. Are the laboratory results really true?
  2. Can the laboratory accurately analyze sample products like my sample?
  3. Can the laboratory reproduce the sample results for my type of sample?

Now let’s discuss the most important QC test that will protect your crop and business. That QC sample is the Matrix Sample. In the last article in this series, you were introduced to many QC samples. The Matrix Sample and Duplicate were some of them. Take a look back at Part 3 to familiarize yourself with the definitions.

The key factors of these QC sample types are:

  1. Your sample is used to determine if the analysis used by the laboratory can extract the analyte that is being reported back to you. This is performed by the following steps:
    1. Your sample is analyzed by the laboratory as received.
    2. Then a sub-sample of your sample is spiked with a known concentration of the analyte you are looking for (e.g. pesticides, bacteria, organic chemicals, etc.).
    3. The difference between the sample with and without a spike indicates whether the laboratory can even find the analyte of concern and whether the percent recovery is acceptable.
    4. Examples of failures are from my experiences:
      1. Laboratory 1 spiked a known amount of a pesticide into a wastewater matrix. (e.g. Silver into final treatment process water). The laboratory failed to recover any of the spiked silver. Therefore the laboratory results for these types of sample were not reporting any silver, but silver may be present. This is where laboratory results would be false negatives and the laboratory method may not work on the matrix (your sample) correctly. .
      2. Laboratory 2 ran an analysis for a toxic compound (e.g. Cyanide in final waste treatment discharge). A known amount of cyanide was spiked into a matrix sample and 4 times the actual concentration of that cyanide spike was recovered. This is where laboratory results would be called false positives and the laboratory method may not work on the matrix (your sample) correctly.
  2. Can the laboratory reproduce the results they reported to you?
    1. The laboratory needs to repeat the matrix spike analysis to provide duplicate results. Then a comparison of the results from the first matrix spike with its duplicate results will show if the laboratory can duplicate their test on your sample.
      1. If the original matrix spike result and the duplicate show good agreement (e.g. 20% relative percent difference or lower). Then you can be relatively sure that the result you obtained from the laboratory is true.
      2. But, if the original matrix spike result and the duplicate do not show good agreement (e.g. greater than 20% relative percent difference). Then you can be sure that the result you obtained from the laboratory is not true and you should question the laboratory’s competence.

Now, the question is why a laboratory would not perform these matrix spike and duplicate QC samples? Well, the following may apply:

  1. These matrix samples take too much time.
  2. These matrix samples add a cost that the laboratory cannot recover.
  3. These matrix samples are too difficult for the laboratory staff to perform.
  4. Most importantly: Matrix samples show the laboratory cannot perform the analyses correctly on the matrix.

So, what types of cannabis matrices are out there? Some examples include bud, leaf, oils, extracts and edibles. Those are some of the matrices and each one has their own testing requirements. So, what should you require from your laboratory?

  1. The laboratory must use your sample for both a matrix spike and a duplicate QC sample.
  2. The percent recovery of both the matrix spike and the duplicate will be between 80% and 120%. If either of the QC samples fail, then you should be notified immediately and the samples reanalyzed.
  3. If the relative percent difference between the matrix spike and the duplicate will be 20% or less. If the QC samples fail, then you should be notified immediately and the samples should be reanalyzed.

The impact of questionable laboratory results on your business with failing or absent matrix spike and the duplicate QC samples can be prevented. It is paramount that you hold the laboratory responsible to produce results that are representative of your sample matrix and that are true.

The next article will focus on how your business will develop a quality plan for your laboratory service provider with a specific focus on the California Code Of Regulations, Title 16, Division 42. Bureau Of Cannabis Control requirements.

Dr. Ed Askew
From The Lab

Quality Plans for Lab Services: Managing Risks as a Grower, Processor or Dispensary, Part 3

By Dr. Edward F. Askew
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Dr. Ed Askew

Editor’s Note: The views expressed in this article are the author’s opinions based on his experience working in the laboratory industry. This is an opinion piece in a series of articles designed to highlight the potential problems that clients may run into with labs. 


In the last two articles, I discussed the laboratory’s first line of defense (e.g. certification or accreditation) paperwork wall used if a grower, processor or dispensary (user/client) questioned a laboratory result and the conflicts of interest that exist in laboratory culture. Now I will discuss the second line of defense that a laboratory will present to the user in the paperwork wall: Quality Control (QC) results.

Do not be discouraged by the analytical jargon of the next few articles. I suggest that you go immediately to the conclusions to get the meat of this article and then read the rest of it to set you on the path to see the forest for the trees.

QC in a laboratory consists of a series of samples run by the laboratory to determine the accuracy and precision of a specific batch of samples. So, to start off, let’s look at the definitions of accuracy and precision.QC Charts can provide a detailed overview of laboratory performance in a well-run laboratory.

According to the Standard Methods for the Examination of Water and Wastewater:

Accuracy: estimate of how close a measured value is to the true value; includes expressions for bias and precision.

Precision: a measure of the degree of agreement among replicate analyses of a sample.

A reputable laboratory will measure the Accuracy and Precision of QC samples in a batch of user samples and record these values in both the analytical test report issued to the user and in control charts kept by the laboratory. These control charts can be reviewed by the user if they are requested by the user. These control charts record:

Accuracy (means) chart: The accuracy chart for QC samples (e.g., LRB, CCV, LFBs, LFMs, and surrogates) is constructed from the average and standard deviation of a specified number of measurements of the analyte of interest.

Precision (range) chart: The precision chart also is constructed from the average and standard deviation of a specified number of measurements (e.g., %RSD or RPD) for replicate of duplicate analyses of the analyte of interest.

Now, let’s look at what should be run in a sample batch for cannabis analyses. The typical cannabis sample would have analyses for cannabinoids, terpenes, microbiological, organic compounds, pesticides and heavy metals.

Each compound listed above would require a specific validated analytical method for the type of matrix being analyzed. Examples of specific matrixes are:

  • Cannabis buds, leaves, oil
  • Edibles, such as Chocolates, Baked Goods, Gummies, Candies and Lozenges, etc.
  • Vaping liquids
  • Tinctures
  • Topicals, such as lotions, creams, etc.

Running QC analyses does not guarantee that the user’s specific sample in the batch was analyzed correctly.

Also, both ISO 17025-2005 and ISO 17025-2017 require the use of a validated method.

ISO 17025-2005: When it is necessary to use methods not covered by standard methods, these shall be subject to agreement with the customer and shall include a clear specification of the customer’s requirements and the purpose of the test and/or calibration. The method developed shall have been validated appropriately before use.

ISO 17025-2017: The laboratory shall validate non-standard methods, laboratory-developed methods and standard methods used outside their intended scope or otherwise modified. The validation shall be as extensive as is necessary to meet the needs of the given application or field of application.

Validation procedures can be found in a diverse number of analytical chemistry associations (such as AOACand ASTM) but the State of California has directed users and laboratories to the FDA manual “Guidelines for the Validation of Chemical Methods for the FDA FVM Program, 2nd Edition, 2015

The laboratory must have on file for user review the following minimum results in an analytical statistical report validating their method:

  • accuracy,
  • limit of quantitation,
  • ruggedness,
  • precision,The user must look beyond the QC data provided in their analytical report or laboratory control charts.
  • linearity (or other calibration model),
  • confirmation of identity
  • selectivity,
  • range,
  • spike recovery.
  • limit of detection,
  • measurement uncertainty,

The interpretation of an analytical statistical report will be discussed in detail in the next article. Once the validated method has been selected for the specific matrix, then a sample batch is prepared for analysis.

Sample Batch: A sample batch is defined as a minimum of one (1) to a maximum of twenty (20) analytical samples run during a normal analyst’s daily shift. A LRB, LFB, LFM, LFMD, and CCV will be run with each sample batch. Failure of any QC sample in sample batch will require a corrective action and may require the sample batch to be reanalyzed. The definitions of the specific QC samples are described later.

The typical sample batch would be set as:

  • Instrument Start Up
  • Calibration zero
  • Calibration Standards, Quadratic
  • LRB
  • LFB
  • Sample used for LFM/LFMD
  • LFM
  • LFMD
  • Samples (First half of batch)
  • CCV
  • Samples (Second half of batch)
  • CCV

The QC samples are defined as:

Calibration Blank: A volume of reagent water acidified with the same acid matrix as in the calibration standards. The calibration blank is a zero standard and is used to calibrate the ammonia analyzer

Continuing Calibration Verification (CCV): A calibration standard, which is analyzed periodically to verify the accuracy of the existing calibration for those analytes.

Calibration Standard: A solution prepared from the dilution of stock standard solutions. These solutions are used to calibrate the instrument response with respect to analyte concentration

Laboratory Fortified Blank (LFB): An aliquot of reagent water or other blank matrix to which known quantities of the method analytes and all the preservation compounds are added. The LFB is processed and analyzed exactly like a sample, and its purpose is to determine whether the methodology is in control, and whether the laboratory is capable of making accurate and precise measurements.

Laboratory Fortified Sample Matrix/Duplicate (LFM/LFMD) also called Matrix Spike/Matrix Spike Duplicate (MS/MSD): An aliquot of an environmental sample to which known quantities of ammonia is added in the laboratory. The LFM is analyzed exactly like a sample, and its purpose is to determine whether the sample matrix contributes bias to the analytical results. The background concentrations of the analytes in the sample matrix must be determined in a separate aliquot and the measured values in the LFM corrected for background concentrations (Section 9.1.3).Laboratories must validate their methods.

Laboratory Reagent Blank (LRB): A volume of reagent water or other blank matrix that is processed exactly as a sample including exposure to all glassware, equipment, solvents and reagents, sample preservatives, surrogates and internal standards that are used in the extraction and analysis batches. The LRB is used to determine if the method analytes or other interferences are present in the laboratory environment, the reagents, or the apparatus.

Once a sample batch is completed, then some of the QC results are provided in the user’s analytical report and all of the QC results should be recorded in the control charts identified in the accuracy and precision section above.

But having created a batch and performing QC sample analyses, the validity of the user’s analytical results is still not guaranteed. Key conclusion points to consider are:

  1. Laboratories must validate their methods.
  2. Running QC analyses does not guarantee that the user’s specific sample in the batch was analyzed correctly.
  3. QC Charts can provide a detailed overview of laboratory performance in a well-run laboratory.

The user must look beyond the QC data provided in their analytical report or laboratory control charts. Areas to look at will be covered in the next few articles in this series.

Terpene_KAS2
From The Lab

The Other Side of Cannabis: Terpenes

By Dr. Zacariah Hildenbrand, Allegra Leghissa, Dr. Kevin A. Schug
2 Comments
Terpene_KAS2

Have you ever wondered why all beers have that strong, characteristic smell? Or why you could tell the smell of cannabis apart from any other plant? The answer is simple – terpenes.

These 55,000 different molecules are responsible for a majority of the odors and fragrances around us, from a pine forest, to the air diffuser in your house 1–3. They all share the same precursor, isoprene, and because of that, they are all related and have similar molecular structures. Unfortunately, it is this uncanny similarity that makes their analysis so challenging; we still lack a complete list of which terpenes expected to be found in each given plant species 1,2.

Many different methods have been developed in an effort to provide a time-optimized and straightforward analysis. Gas chromatography (GC) is usually center stage due to the volatility of the terpenes. Therefore, there is significant concern with the type of GC detector used 2.

The flame ionization detector (FID) is a good quantitative detector for GC, but qualitatively it does not provide any information, except for retention time; the differentiation between terpene species is achieved solely by use of retention indices (RI), which are based on elution times from a particular GC stationary phase. The best part of the FID is its low cost, reliability, and relatively easy interface, which make it an effective tool for quality control (QC) but less so with respect to research and discovery 2.

The primary choice for a research setting is the mass spectrometer (MS) detector. It is more expensive and complicated than FID, but importantly, it provides both good quantitative capabilities, and it provides mass spectra for each species that elutes from the chromatograph. However, for terpene analysis, it may still not be the best detector choice. Since terpene class molecules share many structural and functional similarities, even their fragmentation and sub-sequential identification by MS may lead to inconsistent results, which need to be confirmed by use of RI. Still, MS is a better qualitative analysis tool than the FID, especially for distinguishing non-isobaric terpenes 2.

Recently, new technology based on vacuum ultraviolet spectroscopy (VUV) has been developed as a new GC detector. The VUV detector enables analysis of virtually all molecules; virtually all chemical compounds absorb light in the range in the 125-240 nm wavelength range probed by the detector, making it an essentially universal detector 4–11. Previously, spectroscopic absorption detectors for GC have lacked sufficient energy to measure absorption of most GC-amenable species. The VUV detector fills a niche, which is complementary to MS detection in terms of the qualitative information it provides.

Terpene_KAS2
Figure 1: A, Section of the chromatographic separation of a terpenes standard mix; B, highlight of the co-eluting terpenes, camphor and (-)-isopulegol; C, differences in the absorbance spectra of camphor and (-)-isopulegol.

With the VUV detector, each compound exhibits its own unique absorbance spectrum. Even isomers and isobars, which are prevalent in terpene mixtures and can be difficult to distinguish different species by their electron ionization mass spectra, can be well differentiated based on their VUV spectra 6,9,10.  Nevertheless, because analytes exhibit different spectra, it is not required to achieve a perfect chromatographic separation of the mixture components. Co-eluting peaks can be separated post-run through the use of library spectra and software inherent to the instrument 4,10. This ability is called “deconvolution”, and it is based on the fact that two co-eluting terpenes will give a peak with an absorbance spectrum equal to the sum of the two single absorbance spectra 4. Figure 1 shows the deconvolution process for two co-eluting terpenes, camphor and (-)-isopulegol. Due to their different absorbance spectra (Figure 1C), it is possible to fully separate the two peaks in post-run, obtaining sharp peaks for both analytes 6.

The deconvolution process has been shown to yield precise and accurate results. Thus, chromatographic resolution can be sacrificed in favor of spectroscopic resolution; this enables the development of methods with faster run times. With the ability to deconvolve unresolved peaks, a long temperature ramp to chromatographically separate all isomeric terpenes is not required 6. Additionally, the presence of coeluting components, which might normally go undetected with some GC detectors, can be easily judged based on comparison of the measured spectra with pure reference spectra contained in the VUV spectral library.

The other issue in terpenes analysis is the extraction process. Terpenes can be extracted with the use of solvents (e.g., methanol, ethanol, hexane, and cyclohexane, among others), but the process is usually time-consuming, costly and not so environmentally-friendly 2. The plant needs to be manually crushed and then aliquots of solvent are used to extract components from the plant, ideally at least 3 times and combined to achieve acceptable results. The problem is that some terpenes may respond better to a certain solvent, making their extraction easier and more optimized than for others 2. The choice of solvent can cause discrimination against the extraction some terpenes, which limits the comprehensiveness of analysis.

Headspace is another technique that can be used for the sample preparation of terpenes. Headspace sampling is based on heating the solid or liquid sample inside a sealed vial, and then analyzing the air above it after sufficient equilibration. In this way, only volatile analytes are extracted from the solid/liquid sample into the gas phase; this allows relatively interference-free sampling 12–14.

How do we know whether our extraction analysis methods are correct and comprehensive for a certain plant sample? Unfortunately, there is not a complete list of available molecules for each plant species, and even if two specimens may smell really similar to our nose, their terpenes profiles may be notably different. When working with a new plant material, it is difficult to predict the extraction efficiency for the vast array of terpenes that may be present. We can only perform it with different extraction and detection methods, and compare the results.

The route for a comprehensive and fast analysis of terpenes is therefore still long; however, their intoxicating aromas and inherent medicinal value has provided a growing impetus for researchers around the world. Considering the evolving importance of Cannabis and the growing body of evidence on the synergistic effects between terpenes and cannabinoids, it is likely that newly improved extraction and analysis methods will be developed, paving the way for a more complete list of terpene species that can be found in different cultivars. The use of new analytical technologies, such as the VUV detector for GC, should aid considerably in this endeavor.


References:

[1]          Breitmaier E., Terpenes: Flavors, Fragrances, Pharmaca, Pheromones. John Wiley & Sons 2006.

[2]          Leghissa A., Hildenbrand Z. L., Schug K. A., A Review of Methods for the Chemical Characterization of Cannabis Natural Products. J. Sep. Sci.2018, 41, 398–415 .

[3]          Benvenuto E., Misra B. B., Stehle F., Andre C. M., Hausman J.-F., Guerriero G., Cannabis sativa: The Plant of the Thousand and One Molecules. Front. Plant Sci2016, 719, DOI: 10.3389/fpls.2016.00019.

[4]          Schug K. A., Sawicki I., Carlton D. D., Fan H.,Mcnair H. M.,Nimmo J. P., Kroll P.,Smuts J.,Walsh P., Harrison D., Vacuum Ultraviolet Detector for Gas Chromatography. Anal. Chem.2014, 86, 8329–8335 .

[5]          Fan H.,Smuts J., Walsh P.,Harrison D., Schug K. A., Gas chromatography-vacuum ultraviolet spectroscopy for multiclass pesticide identification. J. Chromatogr. A2015, DOI: 10.1016/j.chroma.2015.02.035.

[6]          Qiu C.,Smuts J., Schug K. A., Analysis of terpenes and turpentines using gas chromatography with vacuum ultraviolet detection. J. Sep. Sci.2017, 40, 869–877 .

[7]          Leghissa A., Smuts J., Qiu C., Hildenbrand Z. L., Schug K. A., Detection of cannabinoids and cannabinoid metabolites using gas chromatography-vacuum ultraviolet spectroscopy. Sep. Sci. Plus2018, 1.

[8]          Bai L.,Smuts J., Walsh P., Fan H., Hildenbrand Z., Wong D., Wetz D., Schug K. A., Permanent gas analysis using gas chromatography with vacuum ultraviolet detection. J. Chromatogr. A2015,1388, 244–250 .

[9]          Skultety L., Frycak P., Qiu C.,Smuts J., Shear-Laude L., Lemr K., Mao J. X., Kroll P., Schug K. A., Szewczak A., Vaught C., Lurie I., Havlicek V., Resolution of isomeric new designer stimulants using gas chromatography – Vacuum ultraviolet spectroscopy and theoretical computations. Anal. Chim. Acta2017, 971, 55–67 .

[10]       Bai L., Smuts J., Walsh P., Qiu C., McNair H. M., Schug K. ., Pseudo-absolute quantitative analysis using gas chromatography–vacuum ultraviolet spectroscopy–a tutorial. Anal. Chim. Acta2017, 953, 10–22 .

[11]       Schenk J., Nagy G., Pohl N. L. B., Leghissa A., Smuts J., Schug K. A., Identification and deconvolution of carbohydrates with gas chromatography-vacuum ultraviolet spectroscopy. J. Chromatogr. A2017, 1513, 210–221 .

[12]       Van Opstaele F., De Causmaecker B., Aerts G., De Cooman L., Characterization of novel varietal floral hop aromas by headspace solid phase microextraction and gas chromatography-mass spectrometry/olfactometry. J. Agric. Food Chem.2012, 60, 12270−12281 .

[13]       Hamm S., Bleton J., Connan J., Tchapla A., A chemical investigation by headspace SPME and GC-MS of volatile and semi-volatile terpenes in various olibanum samples. Phytochemistry2005,66, 1499–1514 .

[14]       Aberl A., Coelhan M., Determination of volatile compounds in different hop Varieties by headspace-trap GC/MS-in comparison with conventional hop essential oil analysis. J. Agric. Food Chem.2012, 60, 2785−2792 .

Swetha Kaul, PhD

Colorado vs. California: Two Different Approaches to Mold Testing in Cannabis

By Swetha Kaul, PhD
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Swetha Kaul, PhD

Across the country, there is a patchwork of regulatory requirements that vary from state to state. Regulations focus on limiting microbial impurities (such as mold) present in cannabis in order for consumers to receive a safe product. When cultivators in Colorado and Nevada submit their cannabis product to laboratories for testing, they are striving to meet total yeast and mold count (TYMC) requirements.In a nascent industry, it is prudent for state regulators to reference specific testing methodologies so that an industry standard can be established.

TYMC refers to the number of colony forming units present per gram (CFU/g) of cannabis material tested. CFU is a method of quantifying and reporting the amount of live yeast or mold present in the cannabis material being tested. This number is determined by plating the sample, which involves spreading the sample evenly in a container like a petri dish, followed by an incubation period, which provides the ideal conditions for yeast and mold to grow and multiply. If the yeast and mold cells are efficiently distributed on a plate, it is assumed that each live cell will give rise to a single colony. Each colony produces a visible spot on the plate and this represents a single CFU. Counting the numbers of CFU gives an accurate estimate on the number of viable cells in the sample.

The plate count methodology for TYMC is standardized and widely accepted in a variety of industries including the food, cosmetic and pharmaceutical industries. The FDA has published guidelines that specify limits on total yeast and mold counts ranging from 10 to 100,000 CFU/g. In cannabis testing, a TYMC count of 10,000 is commonly used. TYMC is also approved by the AOAC for testing a variety of products, such as food and cosmetics, for yeast and mold. It is a fairly easy technique to perform requiring minimal training, and the overall cost tends to be relatively low. It can be utilized to differentiate between dead and live cells, since only viable living cells produce colonies.

Petri dish containing the fungus Aspergillus flavus
Petri dish containing the fungus Aspergillus flavus.
Photo courtesy of USDA ARS & Peggy Greb.

There is a 24 to 48-hour incubation period associated with TYMC and this impedes speed of testing. Depending on the microbial levels in a sample, additional dilution of a cannabis sample being tested may be required in order to count the cells accurately. TYMC is not species-specific, allowing this method to cover a broad range of yeast and molds, including those that are not considered harmful. Studies conducted on cannabis products have identified several harmful species of yeast and mold, including Cryptococcus, Mucor, Aspergillus, Penicillium and Botrytis Cinerea. Non-pathogenic molds have also been shown to be a source of allergic hypersensitivity reactions. The ability of TYMC to detect only viable living cells from such a broad range of yeast and mold species may be considered an advantage in the newly emerging cannabis industry.

After California voted to legalize recreational marijuana, state regulatory agencies began exploring different cannabis testing methods to implement in order to ensure clean cannabis for the large influx of consumers.

Unlike Colorado, California is considering a different route and the recently released emergency regulations require testing for specific species of Aspergillus mold (A. fumigatus, A. flavus, A. niger and A. terreus). While Aspergillus can also be cultured and plated, it is difficult to differentiate morphological characteristics of each species on a plate and the risk of misidentification is high. Therefore, positive identification would require the use of DNA-based methods such as polymerase chain reaction testing, also known as PCR. PCR is a molecular biology technique that can detect species-specific strains of mold that are considered harmful through the amplification and analysis of DNA sequences present in cannabis. The standard PCR testing method can be divided into four steps:

  1. The double stranded DNA in the cannabis sample is denatured by heat. This refers to splitting the double strand into single strands.
  2. Primers, which are short single-stranded DNA sequences, are added to align with the corresponding section of the DNA. These primers can be directly or indirectly labeled with fluorescence.
  3. DNA polymerase is introduced to extend the sequence, which results in two copies of the original double stranded DNA. DNA polymerases are enzymes that create DNA molecules by assembling nucleotides, the building blocks of DNA.
  4. Once the double stranded DNA is created, the intensity of the resulting fluorescence signal can uncover the presence of specific species of harmful Aspergillus mold, such as fumigatus.

These steps can be repeated several times to amplify a very small amount of DNA in a sample. The primers will only bind to the corresponding sequence of DNA that matches that primer and this allows PCR to be very specific.

PCR testing is used in a wide variety of applications
PCR testing is used in a wide variety of applications
Photo courtesy of USDA ARS & Peggy Greb.

PCR is a very sensitive and selective method with many applications. However, the instrumentation utilized can be very expensive, which would increase the overall cost of a compliance test. The high sensitivity of the method for the target DNA means that there are possibilities for a false positive. This has implications in the cannabis industry where samples that test positive for yeast and mold may need to go through a remediation process to kill the microbial impurities. These remediated samples may still fail a PCR-based microbial test due to the presence of the DNA. Another issue with the high selectivity of this method is that other species of potentially harmful yeast and mold would not even be detected. PCR is a technique that requires skill and training to perform and this, in turn, adds to the high overall cost of the test.

Both TYMC and PCR have associated advantages and disadvantages and it is important to take into account the cost, speed, selectivity, and sensitivity of each method. The differences between the two methodologies would lead to a large disparity in testing standards amongst labs in different states. In a nascent industry, it is prudent for state regulators to reference specific testing methodologies so that an industry standard can be established.

dSPE cleanups

The Grass Isn’t Always Greener: Removal of Purple Pigmentation from Cannabis

By Danielle Mackowsky
1 Comment
dSPE cleanups
strains
Cannabis strains used (clockwise from top left): Agent Orange, Tahoe OG, Blue Skunk, Grand Daddy and Grape Drink

Cannabis-testing laboratories have the challenge of removing a variety of unwanted matrix components from plant material prior to running extracts on their LC-MS/MS or GC-MS. The complexity of the cannabis plant presents additional analytical challenges that do not need to be accounted for in other agricultural products. Up to a third of the overall mass of cannabis seed, half of usable flower and nearly all extracts can be contributed to essential oils such as terpenes, flavonoids and actual cannabinoid content1. The biodiversity of this plant is exhibited in the over 2,000 unique strains that have been identified, each with their own pigmentation, cannabinoid profile and overall suggested medicinal use2. While novel methods have been developed for the removal of chlorophyll, few, if any, sample preparation methods have been devoted to removal of other colored pigments from cannabis.

QuEChERS
Cannabis samples following QuEChERS extraction

Sample Preparation

Cannabis samples from four strains of plant (Purple Drink, Tahoe OG, Grand Daddy and Agent Orange) were hydrated using deionized water. Following the addition of 10 mL acetonitrile, samples were homogenized using a SPEX Geno/Grinder and stainless steel grinding balls. QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) non-buffered extraction salts were then added and samples were shaken. Following centrifugation, an aliquot of the supernatant was transferred to various blends of dispersive SPE (dSPE) salts packed into centrifugation tubes. All dSPE tubes were vortexed prior to being centrifuged. Resulting supernatant was transferred to clear auto sampler vials for visual analysis. Recoveries of 48 pesticides and four mycotoxins were determined for the two dSPE blends that provided the most pigmentation removal.

Seven dSPE blends were evaluated for their ability to remove both chlorophyll and purple pigmentation from cannabis plant material:

  • 150 mg MgSO4, 50 mg PSA, 50 mg C18, 50 mg Chlorofiltr®
  • 150 mg MgSO4, 50 mg C18, 50 mg Chlorofiltr®
  • 150 mg MgSO4, 50 mg PSA
  • 150 mg MgSO4, 25 mg C18
  • 150 mg MgSO4, 50 mg PSA, 50 mg C18
  • 150 mg MgSO4, 25 mg PSA, 7.5 mg GCB
  • 150 mg MgSO4, 50 mg PSA, 50 mg C18, 50 mg GCB

Based on the coloration of the resulting extracts, blends A, F and G were determined to be the most effective in removing both chlorophyll (all cannabis strains) and purple pigments (Purple Drink and Grand Daddy). Previous research regarding the ability of large quantities of GCB to retain planar pesticides allowed for the exclusion of blend G from further analyte quantitation3. The recoveries of the 48 selected pesticides and four mycotoxins for blends A and F were determined.

dSPE cleanups
Grand Daddy following various dSPE cleanups

Summary

A blend of MgSO4, C18, PSA and Chlorofiltr® allowed for the most sample clean up, without loss of pesticides and mycotoxins, for all cannabis samples tested. Average recovery of the 47 pesticides and five mycotoxins using the selected dSPE blend was 75.6% were as the average recovery when including GCB instead of Chlorofiltr® was 67.6%. Regardless of the sample’s original pigmentation, this blend successfully removed both chlorophyll and purple hues from all strains tested. The other six dSPE blends evaluated were unable to provide the sample clean up needed or had previously demonstrated to be detrimental to the recovery of pesticides routinely analyzed in cannabis.


References

(1)           Recommended methods for the identification and analysis of cannabis and cannabis products, United Nations Office of Drugs and Crime (2009)

(2)            W. Ross, Newsweek, (2016)

(3)            Koesukwiwat, Urairat, et al. “High Throughput Analysis of 150 Pesticides in Fruits and Vegetables Using QuEChERS and Low-Pressure Gas Chromatography Time-of-Flight Mass Spectrometry.” Journal of Chromatography A, vol. 1217, no. 43, 2010, pp. 6692–6703., doi:10.1016/j.chroma.2010.05.012.

Sunrise Genetics Partners With RPC, Begins Genetic Testing in Canada

By Aaron G. Biros
No Comments

Sunrise Genetics, Inc., the parent company of Marigene and Hempgene, announced their partnership with New Brunswick Research & Productivity Council (RPC) this week, according to a press release. The company has been working in the United States for a few years now doing genomic sequencing and genetic research with headquarters based in Fort Collins, CO. This new partnership, compliant with Health Canada sample submission requirements, allows Canadian growers to submit plants for DNA extraction and genomic sequencing.

Sunrise Genetics researches different cannabis cultivars in the areas of target improvement of desired traits, accelerated breeding and expanding the knowledge base of cannabis genetics. One area they have been working on is genetic plant identification, which uses the plant’s DNA and modern genomics to create authentic, reproducible, commercial-ready strains.

Matt Gibbs, president of Sunrise Genetics, says he is very excited to get working on cannabis DNA testing in Canada. “RPC has a long track record of leadership in analytical services, especially as it relates to DNA and forensic work, giving Canadian growers their first real option to submit their plant samples for DNA extraction through proper legal channels,” says Gibbs. “The option to pursue genomic research on cannabis is now at Canadian cultivator’s fingertips.”

Canada’s massive new cannabis industry, which now has legal recreational and medical use, sales and cultivation, previously has not had many options for genetic testing. Using their genetic testing capabilities, they hope this partnership will better help Canadian cultivators easily apply genomic testing for improved plant development. “I’m looking forward to working with more Canadian cultivators and breeders; the opportunity to apply genomics to plant improvement is a win-win for customers seeking transparency about their Cannabis product and producers seeking customer retention through ‘best-in-class’ cannabis and protectable plant varieties,” says Gibbs. The partnership also ensures samples will follow the required submission process for analytical testing, but adding the service option of genetic testing so growers can find out more about their plants beyond the regular gamut of tests.

RPC is a New Brunswick provincial research organization (PRO), a research and technology organization (RTO) that offers R&D testing and technical services. With 130 scientists, engineers and technologists, RPC offers a wide variety of testing services, including air quality, analytical chemistry of cannabis, material testing and a large variety of pilot facilities for manufacturing research and development.

They have over 100 accreditations and certifications including an ISO 17025 scope from the Standards Council of Canada (SCC) and is ISO 9001:2008 certified. This genetic testing service for cannabis plants is the latest development in their repertoire of services. “This service builds on RPC’s established genetic strengths and complements the services we are currently offering the cannabis industry,” says Eric Cook, chief executive officer of RPC.

Using Cloud-Based LIMS To Improve Efficiency In Cannabis Labs

By Shonali Paul
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Cannabis testing laboratories around the country are expanding quickly, taking on new clients and growing their business incrementally. Many of these labs are receiving a large number of test requests from growers for potency testing, terpene profiling, pesticide screening, residual solvent screening, heavy metal testing, microbial analysis and even genetic testing. To keep pace with the number of test requests received, efficient data, sample and test management is imperative.

Considering the magnitude of cannabis testing, data management using spreadsheets is a serious impediment to quality assurance. Data being recorded in spreadsheets is error-prone and difficult to manage. Furthermore, using spreadsheets does not allow labs to adhere to regulatory guidelines that demand strict accounting for every gram of the sample, right from reception, consumption for testing, to disposal.

Log samples, keep track of Chain of Custody(CoC), track samples from initial location in the lab through disposal by recording location, custodians and other metadata

To overcome such data management challenges and improve the operational efficiency of cannabis testing laboratories, a Laboratory Information Management System (LIMS) plays a significant role. LIMS are much more capable than spreadsheets and paper-based tools for managing analytical and operational activities. LIMS enhances the productivity and quality by eliminating the manual data entry. With its built-in audit trail capability, LIMS helps labs adhere to regulatory standards.

LIMS can provide companies with a method to manage samples, records and test results, and ensures regulatory compliance by increasing traceability. LIMS can also be integrated with other lab instrumentation and enterprise systems, enabling easier transmission of information across the lab and the organization, reducing manual efforts and improving decision-making.

Account for the entire quantity of sample received, used and disposed

Multiple resources are also available to assist labs in preparing for quality assurance and accreditation, LIMS being one of them. LIMS can help cannabis labs with instrument integration, and automate reporting to help improve efficiencies and reduce errors. LIMS, such as CloudLIMS Lite, a cloud-based LIMS, automates cannabis-testing workflows right from sample collection, data recording, managing test chain of custody, sample weight accounting to report generation. With data security and audit trails, a LIMS provides traceable documentary evidence required to achieve ISO 17025 accreditation for highly regulated labs. Above all, cloud-enabled systems are often low in the total cost of acquisition, have maintenance outsourced, and are scalable to help meet the ever-changing business and regulatory compliance needs.

Incorporate all tests, instruments, sample information and result data (etc.) in one place

Cloud-based products are secure, easy to deploy and scalable. A cloud product is typically hosted on a server with a guaranteed uptime of 99.5%, allowing for a reliable system, accessible 24×7. Cloud-based LIMS have automatic data backup mechanism that allow for quick turnarounds in case of a server failure or in the eventuality of a natural disaster.

With LIMS in place, cannabis labs can manage sample and requisition-centric records, track sample quantity and location, integrate the test data, and provide online reports to clients. This in turn, reduces the turnaround time for testing and improves the operational efficiency. Besides, audit trail of each and every activity performed by the lab personnel is recorded in the system to ensure that the lab follows regulatory compliance.


Editor’s Note: This is a condensed version of a poster that was submitted and displayed at this year’s Cannabis Science Conference in Portland, Oregon. The authors of the original poster are Arun Apte, Stephen Goldman, Aditi Gade and Shonali Paul.

JCanna Boot Camp Educates Portland Attendees

By Aaron G. Biros
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On Monday, August 28th, attendees of the Cannabis Science Conference descended on Portland, Oregon for a week of educational talks, networking and studying the science of cannabis. On Monday, Chalice Farms, an extracts and infused products company, hosted the full-day JCanna Boot Camp focused on a deep dive behind the scenes of a cannabis production facility. The Cannabis Science Conference, hosted by Josh Crossney, founder of JCanna, takes place August 28th to 30th.

Attendees touring an extraction setup

Attendees were split into five groups where they listened to a variety of educational sessions and toured the facility. A track focused on cultivation, led by Autumn Karcey, president of Cultivo, Inc., detailed all things facility design for cannabis cultivation, including an in-depth look at sanitation and safety. For example, Karcey discussed HVAC cleanliness, floor-to-ceiling sanitation and the hazards associated with negative pressure. These principles, while applicable to most cultivating facilities, applies particularly to commercial-scale grows in a pharmaceutical setting.

Sandy Mangan and Tristan DeBona demonstrating the grinding technique for sample prep

During one session, Sandy Mangan, accounts manager at SPEX Sample Prep and Tristan DeBona, sales specialist at SPEX Sample Prep, demonstrated the basics of sample preparation for detecting pesticides in infused products, such as gummies. That required using their GenoGrinder and FreezerMill, which uses liquid nitrogen to make gummies brittle, then pulverizing them to a powder-like substance that is more conducive for a QuEChERS preparation.

Joe Konschnik and Susan Steinike demonstrate the QuEChERS method

Joe Konschnik, business development manager at Restek, Susan Steinike, product-marketing manager at Restek and Justin Steimling, an analytical chemist at Restek, gave a demonstration of a full QuEChERS extraction of a cannabis sample for pesticide analysis, with attendees participating to learn the basics of sample preparation for these types of tests.

Following those were some other notable talks, including a tour of the extraction instruments and equipment at Chalice Farms, a look inside their commercial kitchen and a discussion of edibles and product formulation. Dr. Uma Dhanabalan, founder of Uplifting Health and Wellness, a physician with over 30 years of experience in research and patient care, led a discussion of physician participation, patient education and drug delivery mechanisms.

Amanda Rigdon, Emerald Scientific, showing some complex matrices in cannabis products

Amanda Rigdon, chief technical officer of Emerald Scientific, offered a demonstration of easy and adaptable sample preparation techniques for potency testing of infused product matrices. Rigdon showed attendees of the boot camp how wildly diverse cannabis products are and how challenging it can be for labs to test them.

The JCanna Canna Boot Camp is a good example of an educational event catered to the cannabis industry that offers real, hands-on experience and actionable advice. Before the two-day conference this week, the boot camp provided a bird’s eye view for attendees of the science of cannabis.

Judging a Craft Cannabis Competition

By Aaron G. Biros
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Willamette Week, a Portland-based publication, is hosting the 2017 Cultivation Classic with Farma, Cascadia Labs, Phylos Bioscience and the Resource Innovation Institute on May 12th. The event is a benefit for the Ethical Cannabis Alliance, an organization that promotes sustainability, labor standards and education surrounding the integrity and ethics of growing cannabis. Cultivation Classic is a competition for pesticide-free cannabis grown in Oregon, according to a press release.

Congressman Earl Blumenauer speaking at last year’s Cultivation Classic
Photo: Bridget Baker, 92bridges.com

While the event’s focus is on the competition, it is just as much a celebration of the craft cannabis community in Oregon. This year’s competition incorporates scientific collaboration like genetic sequencing for the winners by Phylos Bioscience and carbon accounting for all competitors. Keynote speakers include Ethan Russo, medical director of PHYTECS and Dr. Adie Po, co-founder of Habu Health. Congressman Earl Blumenauer, a prominent cannabis legalization advocate in Oregon, will also be speaking at the awards ceremony. You can check out the full schedule and speaker lineup here.

Raymond Bowser, breeder at Home Grown Natural Wonders, is a judge for this year’s Cultivation Classic. He speaks at cannabis conferences around the country and his business created a number of different strains, so he has experience with a myriad of growers and strains. “This time around everyone has really stepped up their game,” says Bowser. “The entries are noticeably better than last year.” When looking at the different samples sent to him, he sees a few key factors as most important in judging the quality. “What I am looking for is simple; a nice smell and a decent look, generally speaking,” says Bowser. “Aesthetics can tell you a lot about how it was grown, temperature changes and the overall care taken in cultivating and curing the flower.” For him, flavor, smell and aesthetics are the big variables to consider.

Photo: Bridget Baker, 92bridges.com

Those are factors that his company holds to high standards in their work, so he judges the samples based on the same variables. “It is what we strive for in our gardens and so far the samples I have tried are fantastic in that regard,” says Bowser. In other competitions that Bowser has judged in the past, they sent him between 40 and 60 strains to judge in seven days. “That is not conducive to a fair evaluation,” says Bowser. “Here, we are getting fourteen or so different strains, so we can sample one strain a day which is how I personally like to do it.”

Bowser is supportive of Cultivation Classic because of their emphasis on the craft industry. “We talk about craft cannabis and breeding craft cultivars at conferences around the country,” says Bowser. “With the rec industry growing so much, we see so many people cutting corners to save money, that it is refreshing to see growers take pride in the craft.” He also stresses the need for good lab testing and sound science in the trade. “I am big on lab testing; it is very important to get all the right analytics when creating strains,” says Bowser. “Cascadia is a solid choice for the competition; they have been a very good, consistent lab.” Emphasizing the local, sustainability-oriented culture surrounding the craft market, Bowser is pleased that this competition supports that same message. “We need to stay true to our Oregon roots and continue to be a clean, green, granola-eating state.”

Photo: Bridget Baker, 92bridges.com

Cascadia Labs is conducting the pesticide and cannabinoid analytics for all submissions and Phylos Bioscience will perform testing for the winners. According to Julie Austin, operations manager at Cascadia Labs, pesticide testing for the Oregon list of analytes was of course a requirement. “Some of the samples submitted had previous tests from us or from other accredited labs, but if they didn’t have those results we did offer a comprehensive pesticide test,” says Austin. The competition’s fee for submission includes the potency and terpenes analysis.

Jeremy Sackett, director of operations at Cascadia Labs, says they test for 11 cannabinoids and 21 terpenes. The samples are divided into groups of THC-dominant samples, CBD-dominant samples and samples with a 1:1 ratio of the two. “The actual potency data will be withheld from judges and competitors until the day of the event,” says Sackett. “We are data driven scientists, but this time we want to have a little fun and bring the heart of this competition back to the good old days: when quality cannabis was gauged by an experience of the senses, not the highest potency number.” The event will take place on May 12th at Revolution Hall in Portland, Oregon. Click here to get tickets to the event.

Annual AOCS Meeting Spotlights Cannabinoid Analytics

By Aaron G. Biros
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The AOCS Annual Meeting is an international science and business forum on fats, oils, surfactants, lipids and related materials. The American Oil Chemist’s Society (AOCS) is holding their meeting in Orlando, Florida from April 30 to May 3, 2017. Last year’s meeting included discussions on best practices and the pros and cons of different extraction techniques, sample preparation, proficiency testing and method development, among other topic areas.

Posters on display for the duration of the Annual Meeting will discuss innovative solutions to test, preparing samples, discovering new compounds and provide novel information about the compounds found in cannabis. David Egerton, vice president of technical operations at CW Analytical (a cannabis testing laboratory in Oakland, CA), is preparing a poster titled Endogenous Solvents in Cannabis Extracts. His abstract discusses testing regulations focusing on the detection of the presence of solvents, despite the fact that endogenous solvents, like acetone and lower alcohols, can be found in all plant material. His study will demonstrate the prevalence of those compounds in both the plant material and the concentrated oil without those compounds being used in production.rsz_am17-editorialpic-cij

The conference features more than 650 oral and poster presentations within 12 interest areas. This year’s technical program includes two sessions specifically designed to address cannabinoid analytics:

Lab Proficiency Programs and Reference Samples

How do you run a lab proficiency program when you cannot send your samples across state lines? What constituents do you test for when state requirements are all different? Are all pesticides illegal to use on cannabis? What pesticides should be tested for when they are mostly illegal to use? How do you analyze proficiency results when there are no standard methods? Learn about these and other challenges facing the cannabis industry. This session encourages open and active discussion, as the cannabis experts want to hear from you and learn about your experiences.

Method Development

The need for high-quality and safe products has spurred a new interest in cannabinoid analytics, including sample preparation, pesticide, and other constituent testing. In this session, a diverse group of scientists will discuss developing analytical methods to investigate cannabis. Learn the latest in finding and identifying terpenes, cannabinoids, matrix effects, and even the best practice for dissolving a gummy bear.

Cynthia Ludwig speaking at last year's meeting
Cynthia Ludwig speaking at last year’s meeting

Cynthia Ludwig, director of technical services at AOCS, says they are making great progress in assembling analytical methods for the production of the book AOCS Collection of Cannabis Analytical Methods. “We are the leading organization supporting the development of analytical methods in the cannabis industry,” says Ludwig. “Many of the contributors in that collection will be presenting at the AOCS Annual Meeting, highlighting some of the latest advances in analyzing cannabis.” The organization hopes to foster more collaboration among those in the cannabis testing industry.

In addition to oral and poster sessions, the 2017 Annual Meeting will feature daily networking activities, more than 70 international exhibitors, two special sessions, and a Hot Topics Symposia which will address how current, critical issues impact the future of the fats and oils industry.