Quantitative determination of CBD and THC and their acid precursors in confiscated cannabis samples by HPLC-DAD.

Analysis of cannabis has gained new importance worldwide, mainly for quality control within the legalized recreational and medical cannabis industry, but also for forensic differentiation between drug-type cannabis and legal products such as fiber hemp and CBD-rich/THC-poor cannabis. We herein present an HPLC-DAD method for quantitative analysis of major neutral and acidic cannabinoids in herbal cannabis and hashish: Δ-tetrahydrocannabinol (THC), Δ-tetrahydrocannabinolic acid A (THCA), cannabidiol (CBD), cannabidiolic acid (CBDA), and cannabinol (CBN). Plant material was dried, homogenized and extracted with a mixture of methanol/hexane. Chromatographic separation of the analytes was achieved on a core-shell C8 column using gradient elution with water/acetonitrile containing 0.1% formic acid. The analytical run time was 13 min and analytes were detected at 210 nm. The method is selective, sensitive, accurate, and precise, as confirmed through validation according to ICH and AOAC guidelines. Linearity in herbal cannabis ranged from 0.04 to 4.00% for the neutral cannabinoids, and from 0.40 to 20% for the acids. Linear ranges in hashish samples were 0.13-13.33% and 1.33-66.66%, respectively. The presented method was successfully applied to characterize 110 cannabis samples seized by the Swiss police, demonstrating its applicability for routine cannabis potency testing in the forensic setting

A preliminary investigation of lung availability of cannabinoids by smoking marijuana or dabbing BHO and decarboxylation rate of THC- and CBD-acids.

Highly potent cannabis concentrates obtained by butane or by supercritical carbon dioxide-extraction are gaining popularity. These extracts called butane hash oil (BHO) with Δ-tetrahydrocannabinolic acid A (THCA) contents above 60% are consumed by flash vaporization on a glowing titanium nail, followed by inhalation of the resulting vapor through a water pipe in a single puff - a technique referred to as "dabbing". We herein investigated the decarboxylation rate of THCA during artificial smoking of cannabis plant material and simulated dabbing, and the lung availability of Δ-tetrahydrocannabinol (THC) which we define as the recovery of THC in the smoke and vapor condensates. Preliminary smoking and dabbing experiments were performed using an apparatus built in-house. Due to availability of cannabidiol (CBD)-rich hemp in Switzerland, we included a sample of CBD flowers in our experiments and investigated the decarboxylation and recovery of cannabidiolic acid (CBDA) and CBD, respectively. Decarboxylation of THCA and CBDA during combustion of the plant material and vaporization of the BHO, respectively, was complete. The high recovery of total THC (75.5%) by dabbing cannot be achieved by smoking marijuana. Lung availability ranged from 12% for mixed cannabis material with a rather low THC content, to approximately 19-27% for marijuana flowers, similar for THC in marijuana as for CBD in CBD-rich marijuana. In reality, when smoking a joint, further losses in recovery must be assumed by additional sidestream smoke. The rather high lung availability of THC via dabbing can explain the increased psychoactive and adverse effects associated with this new trend of cannabis consumption

Development of a rapid column-switching LC-MS/MS method for the quantification of THCCOOH and THCCOOH-glucuronide in whole blood for assessing cannabis consumption frequency

The concentration of 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol (THCCOOH) in whole blood is used as a parameter for assessing the consumption behavior of cannabis consumers. The blood level of THCCOOH-glucuronide might provide additional information about the frequency of cannabis use. To verify this assumption, a column-switching liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the rapid and direct quantification of free and glucuronidated THCCOOH in human whole blood was newly developed. The method comprised protein precipitation, followed by injection of the processed sample onto a trapping column and subsequent gradient elution to an analytical column for separation and detection. The total LC run time was 4.5 min. Detection of the analytes was accomplished by electrospray ionization in positive ion mode and selected reaction monitoring using a triple-stage quadrupole mass spectrometer. The method was fully validated by evaluating the following parameters: linearity, lower limit of quantification, accuracy and imprecision, selectivity, extraction efficiency, matrix effect, carry-over, dilution integrity, analyte stability, and re-injection reproducibility. All acceptance criteria were analyzed and the predefined criteria met. Linearity ranged from 5.0 to 500 μg/L for both analytes. The method was successfully applied to whole blood samples from a large collective of cannabis consumers, demonstrating its applicability in the forensic field