Development of Gas-Chromatographic Method for Simultaneous Determination of Cannabinoids and Terpenes in Hemp

An original gas chromatographic method has been developed for simultaneous determination of major terpenes and cannabinoids in plant samples and their extracts. The main issues to be addressed were the large differences in polarity and volatility between both groups of analytes, but also the need for an exhaustive decarboxylation of cannabinoid acidic forms. Sample preparation was minimised, also by avoiding any analyte derivatisation. Acetone was found to be the most appropriate extraction solvent. Successful chromatographic separation was achieved by using a medium polarity column. Limits of detection ranged from 120 to 260 ng/mL for terpenes and from 660 to 860 ng/mL for cannabinoids. Parallel testing proved the results for cannabinoids are comparable to those obtained from established HPLC methods. Despite very large differences in concentrations between both analyte groups, a linear range between 1 and 100 µg/mL for terpenes and between 10 and 1500 µg/mL for cannabinoids was determined.