| Abstract [eng] |
In this study terpenes in extracts of hemp (Cannabis sativa L.) were determined by gas chromatography and mass spectrometry techniques. GC MS method has been developed and validated for the quantification of terpenes in cannabis plant material, mainly of β-caryophyllene, α-humulene, and caryophyllene oxide. The extraction method was optimized and the GC-MS method validated against reference standards of selected terpenes. During extraction optimization, 10 ml of n-hexane solvent, 5 min time, and 30 °C temperature were chosen. Samples were prepared by extraction of the plant material with n-hexane containing (+)-α-pinene solution as the internal standard. The concentration-response relationship for all analyzed terpenes using the developed method was linear with R2 values > 0.99. The average recoveries for α-humulene and β-caryophyllene in spiked indoor cultivated samples were between 91–116 %. The measured precisions (% relative standard deviation) in all varieties ranged from 1.0 to 7.7 %. The limit of detection and limit of quantitation for both sesquiterpenes were determined to be 0.28–0.30 ppm and 0.83–0.91 ppm, respectively. The proposed method is highly selective, reliable, and accurate and has been applied to the simultaneous determination of these major terpenes in the C. sativa L. biomass. Using this validated GC-MS method 7 terpenes and 4 cannabinoids were identified and 3 sesquiterpenes in all Cannabis sativa L. extracts quantitated: BCP (11.3–14.2 ppm), HUM (3.8 – 4.7 ppm), and BCPO (13.0–17.4 ppm). Using high-performance liquid chromatography analysis two cannabinoids were identified and quantitated: CBD (200.1–261.0 ppm) and CBDA (1847.3–2286.4 ppm). Total radical scavenging activity in Cannabis sativa L. extracts with DPPH method ranged from 87.9 to 123.1 %, and with ABTS method ranged from 162.6 to 197.0 %, and standards: β-caryophyllene (with DPPH: 5.1 % and with ABTS: 75.7 %), CBD (with DPPH: 6.2 % and with ABTS: 21.8 %) and CBDA (with DPPH: 7.8 % and with ABTS: 25.0 %). Better antioxidant activity of C. sativa L. extracts was get when it was used methanol for extracts, not n-hexane. For this reason, we checked the amount of pigments in Cannabis sativa L, which can give antioxidant activity too. Spectrophotometric analysis revealed, that the total amount of chlorophyll a and b, and carotenoids in all Cannabis sativa L. extracts was higher in extract with methanol. |
