Zlatko Mehmedic

Potency Trends of Δ9‐THC and Other Cannabinoids in Confiscated Cannabis Preparations from 1993 to 2008*

Abstract:  The University of Mississippi has a contract with the National Institute on Drug Abuse (NIDA) to carry out a variety of research activities dealing with cannabis, including the Potency Monitoring (PM) program, which provides analytical potency data on cannabis preparations confiscated in the United States. This report provides data on 46,211 samples seized and analyzed by gas chromatography‐flame ionization detection (GC‐FID) during 1993–2008. The data showed an upward trend in the mean Δ9‐tetrahydrocannabinol (Δ9‐THC) content of all confiscated cannabis preparations, which increased from 3.4% in 1993 to 8.8% in 2008. Hashish potencies did not increase consistently during this period; however, the mean yearly potency varied from 2.5–9.2% (1993–2003) to 12.0–29.3% (2004–2008). Hash oil potencies also varied considerably during this period (16.8 ± 16.3%). The increase in cannabis preparation potency is mainly due to the increase in the potency of nondomestic versus domestic samples.

Potency Trends of Δ9-THC and Other Cannabinoids in Confiscated Marijuana from 1980–1997

The analysis of 35,312 cannabis preparations confiscated in the USA over a period of 18 years for delta-9-tetrahydrocannabinol (delta9-THC) and other major cannabinoids is reported. Samples were identified as cannabis, hashish, or hash oil. Cannabis samples were further subdivided into marijuana (loose material, kilobricks and buds), sinsemilla, Thai sticks and ditchweed. The data showed that more than 82% of all confiscated samples were in the marijuana category for every year except 1980 (61%) and 1981 (75%). The potency (concentration of delta9-THC) of marijuana samples rose from less than 1.5% in 1980 to approximately 3.3% in 1983 and 1984, then fluctuated around 3% till 1992. Since 1992, the potency of confiscated marijuana samples has continuously risen, going from 3.1% in 1992 to 4.2% in 1997. The average concentration of delta9-THC in all cannabis samples showed a gradual rise from 3% in 1991 to 4.47% in 1997. Hashish and hash oil, on the other hand, showed no specific potency trends. Other major cannabinoids [cannabidiol (CBD), cannabinol (CBN), and cannabichromene (CBC)] showed no significant change in their concentration over the years.

Changes in Cannabis Potency Over the Last 2 Decades (1995–2014): Analysis of Current Data in the United States

BACKGROUND Marijuana is the most widely used illicit drug in the United States and all over the world. Reports indicate that the potency of cannabis preparation has been increasing. This report examines the concentration of cannabinoids in illicit cannabis products seized by the U.S. Drug Enforcement Administration over the last 2 decades, with particular emphasis on Δ(9)-tetrahydrocannabinol and cannabidiol. METHODS Samples in this report were received over time from materials confiscated by the Drug Enforcement Administration and processed for analysis using a validated gas chromatography with flame ionization detector method. RESULTS Between January 1, 1995, and December 31, 2014, 38,681 samples of cannabis preparations were received and analyzed. The data showed that although the number of marijuana samples seized over the last 4 years has declined, the number of sinsemilla samples has increased. Overall, the potency of illicit cannabis plant material has consistently increased over time since 1995 from ~4% in 1995 to ~12% in 2014. The cannabidiol content has decreased on average from ~.28% in 2001 to <.15% in 2014, resulting in a change in the ratio of Δ(9)-tetrahydrocannabinol to cannabidiol from 14 times in 1995 to ~80 times in 2014. CONCLUSIONS There is a shift in the production of illicit cannabis plant material from regular marijuana to sinsemilla. This increase in potency poses higher risk of cannabis use, particularly among adolescents.

Assessment of cannabinoids content in micropropagated plants of Cannabis sativa and their comparison with conventionally propagated plants and mother plant during developmental stages of growth.

Gas chromatography-flame ionization detection (GC-FID) was used to assess the chemical profile and quantification of cannabinoids to identify the differences, if existing, in the chemical constituents of in vitro propagated plants (IVP), conventionally grown plants (VP) and indoor grown mother plants (MP-Indoor) of a high THC yielding variety of Cannabis sativa L. during different developmental stages of growth. In general, THC content in all groups increased with plant age up to a highest level during the budding stage where the THC content reached a plateau before the onset of senescence. The pattern of changes observed in the concentration of other cannabinoids content with plants age has followed a similar trend in all groups of plants. Qualitatively, cannabinoids profiles obtained using GC-FID, in MP-indoor, VP and IVP plants were found to be similar to each other and to that of the field grown mother plant (MP field) of C. sativa. Minor differences observed in cannabinoids concentration within and among the groups were not found to be statistically significant. Our results confirm the clonal fidelity of IVP plants of C. sativa and suggest that the biochemical mechanism used in this study to produce the micropropagated plants does not affect the metabolic content and can be used for the mass propagation of true to type plants of this species for commercial pharmaceutical use.

Quantitative Determination of Cannabinoids in Cannabis and Cannabis Products Using Ultra-High-Performance Supercritical Fluid Chromatography and Diode Array/Mass Spectrometric Detection.

Ultra‐high‐performance supercritical fluid chromatography (UHPSFC) is an efficient analytical technique and has not been fully employed for the analysis of cannabis. Here, a novel method was developed for the analysis of 30 cannabis plant extracts and preparations using UHPSFC/PDA‐MS. Nine of the most abundant cannabinoids, viz. CBD, ∆8‐THC, THCV, ∆9‐THC, CBN, CBG, THCA‐A, CBDA, and CBGA, were quantitatively determined (RSDs < 6.9%). Unlike GC methods, no derivatization or decarboxylation was required prior to UHPSFC analysis. The UHPSFC chromatographic separation of cannabinoids displayed an inverse elution order compared to UHPLC. Combining with PDA‐MS, this orthogonality is valuable for discrimination of cannabinoids in complex matrices. The developed method was validated, and the quantification results were compared with a standard UHPLC method. The RSDs of these two methods were within ±13.0%. Finally, chemometric analysis including principal component analysis (PCA) and partial least squares‐discriminant analysis (PLS‐DA) were used to differentiate between cannabis samples.

Determination of 11 Cannabinoids in Biomass and Extracts of Different Varieties of Cannabis Using High-Performance Liquid Chromatography.

An HPLC single-laboratory validation was performed for the detection and quantification of the 11 major cannabinoids in most cannabis varieties, namely, cannabidiolic acid (CBDA), cannabigerolic acid (CBGA), cannabigerol (CBG), cannabidiol (CBD), tetrahydrocannabivarin (THCV), cannabinol (CBN), Δ9-trans-tetrahydrocannabinol (Δ9-THC), Δ8-trans-tetrahydrocannabinol (Δ8-THC), cannabicyclol (CBL), cannabichromene (CBC), and Δ9-tetrahydrocannabinolic acid-A (THCAA). The analysis was carried out on the biomass and extracts of these varieties. Methanol-chloroform (9:1, v/v) was used for extraction, 4-androstene-3,17-dione was used as the internal standard, and separation was achieved in 22.2 min on a C18 column using a two- step gradient elution. The method was validated for the 11 cannabinoids. The concentration-response relationship of the method indicated a linear relationship between the concentration and peak area with r2 values of >0.99 for all 11 cannabinoids. Method accuracy was determined through a spike study, and recovery ranged from 89.7 to 105.5% with an RSD of 0.19 to 6.32% for CBDA, CBD, THCV, CBN, Δ9-THC, CBL, CBC, and THCAA; recovery was 84.7, 84.2, and 67.7% for the minor constituents, CBGA, CBG, and Δ8-THC, respectively, with an RSD of 2.58 to 4.96%. The validated method is simple, sensitive, and reproducible and is therefore suitable for the detection and quantification of these cannabinoids in different types of cannabis plant materials.

Quantitative Determination of Δ9-THC, CBG, CBD, Their Acid Precursors and Five Other Neutral Cannabinoids by UHPLC-UV-MS

Cannabinoids are a group of terpenophenolic compounds in the medicinal plant Cannabis sativa (Cannabaceae family). Cannabigerolic acid, Δ9-tetrahydrocannabinolic acid A, cannabidiolic acid, Δ9-tetrahydrocannabinol, cannabigerol, cannabidiol, cannabichromene, and tetrahydrocannabivarin are major metabolites in the classification of different strains of C. sativa. Degradation or artifact cannabinoids cannabinol, cannabicyclol, and Δ8-tetrahydrocannabinol are formed under the influence of heat and light during processing and storage of the plant sample. An ultrahigh-performance liquid chromatographic method coupled with photodiode array and single quadruple mass spectrometry detectors was developed and validated for quantitative determination of 11 cannabinoids in different C. sativa samples. Compounds 1:  - 11: were baseline separated with an acetonitrile (with 0.05% formic acid) and water (with 0.05% formic acid) gradient at a flow rate of 0.25 mL/min on a Waters Cortec UPLC C18 column (100 mm × 2.1 mm I. D., 1.6 µm). The limits of detection and limits of quantitation of the 11 cannabinoids were below 0.2 and 0.5 µg/mL, respectively. The relative standard deviation for the precision test was below 2.4%. A mixture of acetonitrile and methanol (80 : 20, v/v) was proven to be the best solvent system for the sample preparation. The recovery of all analytes was in the range of 97 - 105%. A total of 32 Cannabis samples including hashish, leaves, and flower buds were analyzed.