Quantification of 7 cannabinoids in cannabis oil using GC-MS: Method development, validation and application to therapeutic preparations in Friuli Venezia Giulia region, Italy

The use of therapeutic cannabis preparations in Friuli Venezia Giulia is increasingly expanding. Even if cannabis oil finds its applications in several disorders affecting adults and children, it is not yet a standardized product and, to ensure the quality of the preparation, a quantitative analysis must be carried out before dispensing it to patients. Gas chromatography coupled to mass spectrometry (GC-MS) is a frequently used technique for quantification of cannabinoids, the active compounds of C. sativa. In this context, we developed a GC-MS method for the simultaneous quantification of 7 cannabinoids (CBD, CBDA, CBG, CBN, THCA, THCV and Δ(9)-THC) that is not time and sample consuming: 10 μL of cannabis oil were used for the sample preparation, that consists in derivatization of analytes through silylation. Calibration curves were built from 0.2 to 2 μg/mL. The percentage of accuracy and precision did not exceed the values recommended by validation guidelines. The limit of detection was 0.01 μg/mL; whereas the lower limit of quantification was 0.2 μg/mL. There was no carry over. The proposed GC-MS method showed good sensitivity, specificity, linearity, accuracy, precision and applicability to therapeutic preparations.