Evaluation of different extraction procedures for the quantification of seven cannabinoids in cannabis-based edibles by the use of LC-MS

Abstract

Although still illegal in many countries, food products containing cannabis or marijuana extracts have become very popular in recent years. In the present study, an LC-MS method was developed for the quantitative analysis of seven cannabinoids in various solid and liquid cannabis-based goods. The proposed analytical approach demonstrated satisfactory performance characteristics in terms of linearity (R2≥0.995), accuracy (recovery: 70.0–110 %), precision (intraday RSD: 0.950–6.03 %, interday RSD: 1.02–6.94 %), sensitivity (LOD≤2.19 ng/mL, LOQ≤6.59 ng/mL) and carry-over effect (average carryover signals ≤3.90 %). Solid-phase extraction (SPE), and ultrasound-assisted extraction (UAE) were utilized for the extraction of the analytes from liquid cannabis edibles (beer and energy drink), while Soxhlet and ultrasound-assisted extraction (UAE) were used for solid products (chocolates, hemp seeds, hemp tea). Infusion and decoction processes were followed for cannabis hemp tea and roasted coffee, respectively. UAE provided higher extraction efficiencies for cannabis-based edibles in solid form, while infused-cannabis beverages were extracted more efficiently using the SPE procedure. Cannabidiol (CBD) and cannabigerol (CBG) were the most detectable cannabinoids in all examined samples. Significantly high levels of cannabinoids were detected in cannabis tea extract prepared by the UAE procedure (total cannabinoids: 5440 μg/g). According to the suppliers, all examined samples were supposed to be free of Δ9-tetrahydrocannabinol (Δ9-THC). However, five products were found to contain considerable amounts of this compound (0.600–180 μg/g). Only in the case of cannabis beer, cannabis roasted coffee, and cannabis energy drink, Δ9-THC was not detected.