Simultaneous determination of cannabidiol, cannabinol, and \gD9-tetrahydrocannabinol in human hair by gas chromatography-mass spectrometryin human hair by gas chromatography-mass spectrometry

An analytical method was developed for evaluating the cannabidiol (CBD), cannabinol, (CBN), and \gD9-tetrahydrocannabinol (\gD9-THC) level in human hair using gas chromatography-mass spectrometry (GC-MS). hair samples (50 mg) were washed with isopropyl alcohol and cut into small fragments (<1 mm). After adding a deuterated internal standard, the hair, samples were incubated in 1.0 M NaOH for 10 min at 95°C. The analytes from the resulting hydrolyzed samples were extracted using a mixture ofn-hexane-ethyl acetate (75:25,v/v). The extracts were then evaporated, derivatized, and injected into the GC-MS. The recovery ranges of CBD, CBN and \gD9-THC at three concentration levels were 37.9–94.5% with good correlation coefficients (r2>0.9989). The intra-day precision and accuracy ranged from −9.4% to 17.7%, and the inter-day precision and accuracy ranged from −15.5% to 14.5%, respectively. The limits of detection (LOD) for CBD, CBN, and \gD9-THC were 0.005, 0.002, and 0.006 ng/mg, respectively. The applicability of this method of analyzing the hair samples from cannabis abusers was demonstrated.