Matrix-specific challenges in cannabinoid determination

Abstract

Due to an increased interest in medical cannabis over the years, efficient and reproducible extraction and determination of cannabinoids from different matrices has gained importance. The aim of this study was to identify challenges related to the extraction and analysis of cannabinoids from different matrices. The methodology was divided into 2 phases. Phase 1: Literature review was conducted comparing different matrices in which cannabinoids may be extracted from, sample preparation techniques, and analytical methods used in cannabinoid determination. Phase 2: Visits at the Pharmaceutical Synthesis and Technology laboratory were conducted, where the analysis of cannabinoids in medium chain triglyceride (MCT) oil, hemp seed oil and cosmetics was observed and challenges identified. From 49 articles identified, the most common cannabinoid analysed included tetrahydrocannabinol (THC) (n=41). The most common matrix from which cannabinoids were analysed were oils (n=24). The most common sample preparation technique was solid phase extraction (n=12). High performance liquid chromatography was the chromatographic technique most commonly identified (n=35). The most common detector used was the mass spectrometer (n=38). Challenges identified included difficulty with obtaining clear/unwanted peaks on the chromatogram (n=16) and composition of matrices interfering with extraction (n=12). Phase 2: In the laboratory, challenges encountered included inefficient separation of THC from MCT oil, difficulty with obtaining favourable resolution of chromatographic peaks and the matrix effect. Effective quantification of cannabinoids is highly dependent on overcoming challenges posed by sample preparation and analysis. The wide variety of product types such as oils, balms, and emulsions introduces matrix-specific complexities that influence extraction efficiency and measurement accuracy. Lipid-rich oils can co-extract interfering compounds that suppress analytical signals, balms may entrap cannabinoids within waxy or fatty structures, and emulsions present phase partitioning issues that limit analyte recovery. These matrix effects can compromise both sensitivity and reproducibility, necessitating tailored extraction strategies and rigorous method validation to ensure reliable cannabinoid determination across diverse formulations. By recognizing these matrix-specific issues, analysts can optimize methods for better solvent use, improved analyte recovery, and reduced interference, leading to more accurate and precise results.