Description:
<p>Thymoquinone is a natural chemical found in the plant Nigella sativa. It can also be found insome cultivated Monarda fistulosa plants, which can be steam distilled to produce an essential oil. It hasbeen classified as a pan-assay interference compound, which binds to many proteins indiscriminately. It iscurrently being researched to identify its possible biological properties (Enoli and Hugh, 2018).In this study, essential oil was obtained from Nigella sativa by distillation of water vapour. The amount ofthymoquinone in the essential oil was analyzed by three different analytical methods using a high purityreference analytical standard of thymoquinone in order to compare the methods. In the present study, threechromatographic methods based on direct n-hexane extraction were validated for the thymoquinonequantification in Black Cumin Seed Oil samples, the first one by high-performance liquid chromatographycombined with tandem mass spectrometry (UHPLC-MS/MS), the second one is by gas chromatographymass spectrometry (GC-MSD) and the third one is by gas chromatography flame ionization detector (GCFID). All analytical methods showed good linearity in the calibration range (R² > 0.99). The recoveries ofthymoquinone were greater than 95 % with three techniques. The methods showed good precision,repeatability, and reproducibility. The LOD and LOQ values achieved for UHPLC-MS/MS were 0,299 and0,996 μg/mL, for GC-MSD were 0,348 and 1.161 μg/mL, while for GC-FID were 0,456 and 1,519 μg/mL.The results demonstrate that all three methods exhibit high selectivity for the determination ofthymoquinone. It can be concluded that all three methods are suitable for the determination ofthymoquinone content in black cumin oil, although analyses by UHPLC-MS/MS are one step ahead. </p>