Development and Validation of a Cannabinoid Quantification Method in Oil and Marijuana by UHPLC-MS

Cannabis sativa L. is an ancient species that has been cultivated over the years for various applications, including recreational and medicinal use. Nowadays, the demand for its products has grown significantly, leading to an increase in the search for medicinal oils and a rise in smuggling, making it the main trafficked drug. In this context, our work optimized the extraction process of six cannabinoids in Cannabis oil and marijuana samples, as well as an analytical validation of a quantitative and qualitative method for seven cannabinoids using ultra-performance liquid chromatography coupled with low-resolution mass spectrometry (UHPLC-LTQ-MS). The optimization showed that ethyl acetate is the most suitable solvent for oil extraction. For the marijuana sample, the extraction was performed using the same solvent and sonication and vortex agitation for 10 and 7.5 min, respectively. In the presented method, no matrix effect was observed, where LOQ ranged between 1 and 5 ng mL^-1 and LOD between 0.3 and 1.5 ng mL^-1. Recovery ranged from 84.6 to 107.6% in oil and from 80.6 to 105.9% in marijuana. Precision was evaluated in three ways: within a single day (RSD: 3.14-10.87% in oil, 3.25-10.14% in marijuana), across different days with a second analyst (RSD: 1.98-10.71% in oil, 4.65-12.81% in marijuana), and laboratories with a third analyst (RSD: 5.59-13.94% in oil, 4.65-13.56% in marijuana). The proposed method offers high sensitivity, selectivity, and precision, being adequate and satisfactory for the quantification of CBD, CBN, CBC, CBDA, Δ⁹-THC, and Δ⁹-THCA.