What Do We Test?
Classic Analytical Labs performs the required tests per the Michigan Marijuana Regulatory Agency (MRA) safety compliance facility guidelines. Test methods are selected based upon many factors including both internally and externally validated performance characteristics and statistics. Method performance must be documented and verified to meet all required performance criteria and must be evaluated by an independent, third-party ISO 17025:2017 accreditation body.
Cannabinoids Analysis (Potency)
Cannabinoid concentration or “Potency” is routinely determined using High-Performance Liquid Chromatography (HPLC) with UV detection. We are equipped with a photodiode-array (PDA) based UV detector. The PDA detector offers advanced capabilities compared to a single wavelength or variable wavelength UV detectors. A PDA allows simultaneous acquisition of many wavelengths not just one or two. This additional information along with retention time adds confidence to compound identification. It can help verify that detection of cannabinoids is not interfered with by other compounds like terpenes that we know will be in the sample.
Cannabinoids analysis involves precisely weighing a portion of homogenized sample, following a matrix-specific solvent extraction, and sample clean-up process. With a wide array of sample types available in today’s market, Classic Analytical Labs uses optimized extraction techniques tailored to each of the commodity groups (e.g. flower, chocolate, wax, gummy, oil, baked goods, tinctures, etc.). These techniques use various extraction solvents and solvent mixtures to achieve the highest extraction efficiencies.
Raw data from the HPLC software is transferred into our Laboratory Information Management Software (LIMS), which calculates final results in the form of either weight percent or mg/dose, by taking initial weight, dilution factors, and dose weight (if applicable) into account.
Consistency in production of Marijuana Infused Products (MIPs) is important to patients and regulators. Homogeneity of THC and CBD products ensures that the patient will get consistent medication with every purchase. Some ingredients can separate during production, causing inconsistent cannabinoid content. Homogeneity testing is required on all initial batches of Marijuana Infused Products (MIPs) and every six months thereafter to verify that the dose of THC and CBD are consistent. The allowable variation of THC and CBD is to be within + or – 15% of the intended dose. Homogeneity requires that the lab test 10 different doses or servings at random from the same batch of MIP. If the product is sampled as individual serving/dose then the results will be reported as such. If sampled as a package, the results will be reported as the total THC/CBD per package will be reported. Homogeneity is only required for MIPs, however it is a good idea to ensure that the source oil used is also homogeneous.
Chemical Residue (Pesticides)
Chemical residues, collectively referred to as pesticides, may be analyzed in several ways but nearly all methods use gas and liquid tandem mass spectrometry. Screening methods focus on testing a wide range and number of chemical residues and is common to the food safety industry. This typically involved both GC and LC based technologies. Targeting methods focus on specific pesticides that are needed for compliance testing and have an associated maximum residue limit or action level. Our pesticide testing is focused on meeting the regulatory requirements in Michigan. This allows us to customize our methods and achieve high sensitivity and confident compound identification. We used US FDA and European Union chemical methods guidelines when developing and validating our chemical residue methods. 1st Choice Labs uses both LC-MS/MS and GC-MS/MS instrumentation.
Samples are weighed and prepared in solvent before being filtered and further diluted. SPE, Solid Phase Extraction preparation technique is used for the sample preparation. This allows us to clean-up the sample by removing potential interferences and still preserve our analytes of interest. This is a commonly used prep technique for pesticide residue analysis in food and the environment.
Residual Solvents Analysis
We test residual solvents using headspace gas chromatography with mass spectrometry (HSGC-MS) detection. Solvents are volatile and evaporate easily so we introduce then to the GC-MS using a headspace autosampler. The headspace sampler applies heat to the sample and residual solvents become a vapor and collect in the headspace of the vial. The vapor is then sampled and introduced into the GC. GC-MS allows for low detection limits and enhanced compound identification compared to other detector like FID (flame ionization detection). The mass spectrometer also allows for the detection of multiple compounds that may otherwise coelute, separating them by fragment mass to charge ratio.
Heavy Metals Analysis
Metals analysis is performed using Inductively Coupled Plasma ionization coupled with a mass spectrometer, ICP-MS. The ICP-MS system allows for the simultaneous analysis of multiple elements at low detection limits. Detection limits for this technology are much lower than what are achievable using more common and less expensive Atomic Absorption technology.
Sample preparation for metals involves the processing of sample materials in concentrated acid. Acid digestion involves the weighing of a specific amount of pre-homogenized sample material into a digestion vessel and the addition of various types of acids. Microwave processing allows for digestion to take place inside of a pressure-controlled vessel. This has the potential to improve analyte recoveries, particularly of volatile elements (e.g. As, Hg) along with improving safety and reducing chemical consumption and hazardous waste.
Our heavy metals assay constantly monitors internal standards to ensure the accuracy of results. Sample blanks and laboratory controlled spikes are analyzed with each batch.
Water activity (Aw) testing is performed on a water activity meter. Water activity is the available water vapor of a sample to its environment. In cannabis water activity is an indicator of quality. An Aw value below 0.65 is an indication that mold and other microbial growth is limited. Water activity is a routine and simple test that has been used in food testing for decades.
Foreign Matter Contamination
Foreign matter is examined for by dissecting each node of cannabis flower and examining the surface area of that flower for mold, hair, insect fragments, and inorganic materials. Microscopy is used for the detection of foreign matter within samples. Each sample is fully inspected at both 4X and 40X magnifications, and pictures are taken at each of these magnifications. If any foreign matter is found, the pictures are annotated and marked accordingly.
Analysts are trained to spot specific contamination.
Vitamin E Acetate
Vitamin E acetate (VEA) is a common additive in foods and is considered safe to eat. However, when vaporized VEA is thought to be hazardous to the respiratory system. Processors are required to test any marijuana product intended to be vaporized for VEA (i.e. vape cartridges). 1st Choice utilizes LC-MS/MS for this assay.
qPCR Option – To achieve a colony count in CFU/gram, the sample is prepared in buffer and the DNA is immediately extracted. The amount of target organism DNA found in each sample is relative to the original colony count present in the sample. The DNA is quantified by the Cq or cycle quantitation value. Each cycle in this reaction doubles the amount of DNA present. qPCR instruments continuously measures each sample so that we receive a real time analysis of the DNA present, which is then used to calculate the amount of DNA in the original sample. We plan to quantify CFU counts for Total Yeast and Mold and Total Coliforms. qPCR batches will have positive and NTC, no template controls, analyzed with each sample. An internal standard is built into each assay so that each sample will demonstrate proper analysis.
Plating Option – We may also utilize selective plating technology for the enumeration of total yeast and mold and total coliforms. Specifically, the 3M Petrifilm system may be used. Samples preparation involves weighing out an initial sample and diluting with sterile water or a buffer solution, which may change based on matrix and target microbe. The samples diluents are dispensed onto a 3M Petrifilm plate for the given contaminant, the upper sheet is rolled down and the liquid is spread to fill the entire plate.
The plates are incubated for 24 or 48 hours. When incubation is complete, the plates are removed and analyzed. For each individual analyte, specific biomarkers are noted and a colony count of the plate is acquired. The initial colony count is then processed, taking initial weights and dilutions into account. A final value of CFU/g is compared against the individual State’s limits to provide a pass/fail status. Quality control for microbial testing consists of blank plates for each individual analyte per batch of tests. Sterility checks of the laboratory are performed daily and sampling sterility checks will be performed quarterly.