RESUMO
Cannabidiol (CBD), a major non-psychoactive cannabinoid, has a lot of attention due to its potential relaxing properties and led the trend in commercial CBD aroma/oral hemp seed oil from the Japanese market. In this study, a routine assay for evaluating CBD oil samples was performed using LC coupled with tandem mass spectrometry (LC-MS/MS) and was used to apply the convertible tetrahydrocannabinol (THC) in acetic acid conditions. Based on the electrospray positive ion mode, the detection of cannabidiolic acid (CBDA; m/z 359 > 219), cannabigerolic acid (CBGA; m/z 361 > 343), cannabigerol (CBG; m/z 317 > 193), CBD (m/z 315 > 193), THC (m/z 315 > 193) and cannabinol (CBN; m/z 311 > 223) was performed by satisfying separation with high density of C18 column. Oil samples (50 mg) were diluted with isopropanol (5 mL), to which stable isotope internal standards were added by dilution with methanol/water (50/50), and accuracy rates ranged from 97.8 to 102.2%. This method was used to evaluate the CBD oil products (5 kinds) from the Japanese market. Our survey found obvious counterfeit (non-detectable CBD) CBD oil from Japanese market. Following that, we investigated the conversion of THC in CBD oil samples in simple conditions such as 10% acetic acid and 70 °C for 6 h and discovered that converts THC proportions are approximately 5% ((THC content/CBD content) × 100) and <1.0%. Thus, our developed LC-MS/MS assay could be applied to monitor the CBD concentration and convertible THC from CBD oil.