Potency testing of up to sixteen cannabinoids in hemp-infused edibles using liquid chromatography diode array detector with optional confirmation of identity by electrospray ionization time-of-flight mass spectrometry

Abstract

A LC-DAD method for potency testing of up to sixteen cannabinoids has been developed, validated, and applied for analysis of twenty hemp-infused edibles encompassing a broad range of complex matrices. The method was validated according to ISO 17025 guidelines and met requirements. Samples or their uniform water-dispersions were extracted by methanol under homogenization through pulverization and/or ultrasonication. By spiking abnormal cannabidiol, a cannabinoid not naturally present in hemp, into each sample, extraction recovery was tracked in real time, obtaining 90 to 108% in triplicates with relative standard deviations of 0.5 to 6.5%. The linear calibration range was between 0.008 and 10% (w/w) for each cannabinoid using a 250 µg/mL solution of hemp-infused edibles, except for drinks (sparkling water and tea), where it was between 0.0008 and 1% (w/w) using a 2.5 mg/mL solution. ESI/TOFMS confirmed a good method specificity, i.e., without any false positive identification of individual cannabinoid.

Keywords: Cannabinoid; Diode array detector; Edible; Electrospray ionization time-of-flight mass spectrometry; Hemp; Liquid chromatography.