I feel sorry for anyone that has never seen a plant with 20% THC, and I do mean dry weight. I have been testing Cannabis for over 25 years now and I can assure you, you are wrong! I use or have used both GC/FID, GC/MS, HPLC, HPLC/MS, as well as various qualitative TLC systems including one we designed and built ourselves. I understand the difference between qualitative and quantitative, I understand if a test result is repeatable reproducible or not, and if the results are the same at your lab and several leading experienced Cannabis labs others have run worldwide for decades. Not for testing by the public. How many years have you been testing Cannabis? What methodology? Is it your years of experience that led you to this conclusion that there is no Cannabis with 20% THC?
Sure THC % can be express as dry weight of a manicured bud, what the smoker would smoke, That is how we normally did it. Or as the % in a wet plant, unmanicured. Or as a % of the total Cannabinoids in a plant wet or dry, manicured or not.That said, almost all test for dry weight, manicured bud.
Headspace SorptionThe fragrance concentration problem presented by direct headspace sampling is eliminated in headspace sorption by the accumulative trapping of volatiles over a time period onto an adsorbant. Headspace sorption is undoubtedly the most efficient technique for collecting volatiles from flowers, especially those which release only small amounts. It is also the principal method that has been used for pollen odors. The popularity of headspace sorption lies in the efficacy of volatile collection, the reliable and accurate representation of actual volatile emissions, and the relative ease of applicability in both laboratory and field.
Licensed Producer’s under Canada’s MMPR regulations are required to test potency, and label two Cannabinoids: THC and Cannabidiol. However, the methodology for measuring the presence of these Cannabinoids, and the resulting consequences for patients and medical practioners are not widely understood.The methodologies involve the use of two different instruments.HPLC (Liquid Chromotography) and GC (Gas Chromotography)Gas Chromotography measures the Cannabinoids *after* combustion, while liquid chromotography measures the actual amount of Cannabinoids in the product that is received by the patient. Liquid chromatography is able to detect all forms of the cannabinoids, whether in acid or neutral form. Whereas in gas chromatography the sample must pass through a high temperature inlet which will decarboxylate the acid forms to their neutral state. The conversion is variable from instrument to instrument and method to method and therefore can result in discrepancies in the results from the true values.With CBD vaporization, there are concerns about the percentage of the product which is actually delivered to the patients. A study from October 2014 published by the University of Woolongong and co-authored by Arno Hazencamp of Bedrocan B.V. indicates that a substantially lower % of CBD is delivered at 210C vs 230C, and yet many commercial vaporizers, such as popular and portable PAX Ploom, has a maximum temperature setting of 210C.Dr. Jeff Raber, from the WercShop has argued for years, that GC testing of potency, should never be used, particularly with edibles because of gross inaccuracyWhile others such as Green Leaf Labs in Oregon have argued that GC is the preferable method for testing:Health Canada currently permits potency testing under both methods and Licensed Producers are using both methods. In fact, a recent recall at Peace Naturals involved the use of an HPLC at Peace Naturals and an audit at Health Canada using GC.
Determination of Cannabinoids, Terpenes, and Moisture in Cannabis Buds by Mid-Infrared FTIR Spectroscopy
J Agric Food Chem. 2015 Oct 7Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy on Intact Dried Leaves of Sage (Salvia officinalis L.): Accelerated Chemotaxonomic Discrimination and Analysis of Essential Oil Composition.AbstractSage (Salvia officinalis L.) is cultivated worldwide for its aromatic leaves, which are used as herbal spice, and for phytopharmaceutical applications. Fast analytical strategies for essential oil analysis, performed directly on plant material, would reduce the delay between sampling and analytical results. This would enhance product quality by improving technical control of cultivation. The attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) method described here provides a reliable calibration model for quantification of essential oil components [EOCs; R(2) = 0.96; root-mean-square error of cross-validation (RMSECV) = 0.249 mL 100 g(-1) of dry matter (DM); and range = 1.115-5.280 mL 100 g(-1) of DM] and main constituents [e.g., α-thujone/β-thujone; R(2) = 0.97/0.86; RMSECV = 0.0581/0.0856 mL 100 g(-1) of DM; and range = 0.010-1.252/0.005-0.893 mL 100 g(-1) of DM] directly on dried intact leaves of sage. Except for drying, no further sample preparation is required for ATR-FTIR, and the measurement time of less than 5 min per sample contrasts with the most common alternative of hydrodistillation followed by gas chromatography analysis, which can take several hours per sample.