Ghada M Hadad et al.
Journal of chromatographic science, 52(7), 617-623 (2013-07-03)
A high-performance liquid chromatography method employing diode array detection was developed to determine levels of the major catechins, proanthocyanidin (procyanidin B2), caffeine, thymoquinone and carvacrol and its isomer, thymol, which are present in different natural complex matrices found in commercial