HPTLC densitometric method for analysis of thymoquinone in Nigella sativa extracts and marketed formulations

ObjectiveTo develop a sensitive and accurate high-performance thin layer chromatography method and to determine the quantity of thymoquinone in in two different N. sativa extracts and marketed formulations.MethodsThymoquinone was seperated on aluminum-backed silica gel 60 F254 plates with n-hexane-ethyl acetate 8:2 (%, v/v) as mobile phase.ResultsA compact band was obtained for thymoquinone at Rf value of 0.48±0.04. The calibration plot was linear in the range of 50-700 ng/spot of thymoquinone and the correlation coefficient of 0.998 9 was indicative of good linear dependence of peak area on concentration. Limit of detection (8.67 ng/spot), limit of quantification (17.43 ng/spot) accuracy (less than 2) and recovery (ranging from 98.39-99.17) were found satisfactory.ConclusionsThe developed high-performance thin layer chromatography densitometric method was found cheap, selective, precise and accurate and can be used for routine analysis of N. sativa extracts and marketed formulations.