An overview is given on the manufacture of the different types of tea along with the most important phenolics present in tea and methods of analysis. Compositional data are presented for green, white and black teas. A differentiation of green and black tea by using the ratio between total phenolics and sum of the major catechins seems to be feasible.For white tea there is no general accepted definition. Possible approaches are geographic origin, the botanical variety and the manufacture or the appearance. The differentiation between green and white teas by the ratio mentioned above is not possible.Zusammenfassung: Es wird eine Übersicht über die Teemanufaktur und die resultierenden Arten von Tee gegeben, begleitet von einer Übersicht über einige wichtige Inhaltsstoffe (Flavanole, Zusammenstellung analytischer Methoden zur Bestimmung von (Poly)-phenolen und Daten über grüne, schwarze und weiße Tees). Derzeit scheint eine Differenzierung von grünem und schwarzem Tee über das Flavanol:Gesamtphenolverhältnis möglich.Für weißen Tee gibt es derzeit keine allgemein akzeptierte Definition. Mögliche Ansätze für diese sind die geographische Herkunft, die botanische Varietät oder die Art der Herstellung. Eine Differenzierung durch das Flavanol:Gesamtphenolverhält-nis von grünem und weißen Tee ist nicht realistisch.
The isolation and structural elucidation of the novel myricetin-3-O-[beta-D-glucopyranosyl-(1 --> 3)-alpha-L-rhamnopyranosyl-(1 --> 6)-beta-D-glucopyranoside] from tea (Camellia sinensis (L.) O. Kuntze) by means of HPLC-MS/MS and various NMR techniques is described. The compound was not present in all tea samples analysed. In the case of white tea, it was detected in 20 out of 40 samples analysed (35-255 mg kg(-1)), in green tea it was detected in 18 out of 35 samples in the same concentration range (37-205 mg kg(-1)), while it was found only in 1 sample (51 mg kg(-1)) of 5 black teas analysed.
The aim of this work was to develop and validate a rapid and low cost method for estimation of ibuprofen in pharmaceutical suspensions using Reverse-Phase High Performance Liquid Chromatography. The proposed method was conducted and validated according to International Conference on Harmonization (ICH) requirements. The chromatographic parameters were as follows: column of octyldecylsilyl C18 with dimensions (150 × 4.6) mm, mobile phase composed of acetonitrile with phosphoric acid with a ratio of 50 to 50 each using isocratic mode, flow rate of 1.5 mL/min and injection volume of 5 μL. The detection was carried out using UV detector at 220 nm. The method was validated and showed short retention time for ibuprofen peak at 7.651 min, with linearity in the studied range of 0.4 -1.6 mg/mL (R 2 = 0.9999) and with great accuracy ]percent recovery was (100.48%), percent relative error (-1.511-1.465)%[ and repeatability (RSD% = 0.112 for Retention time). The detection and quantitation limits were determined to be 0.036 and 0.110 mg/mL, respectively. This method was applied successfully to determine the content of ibuprofen in three commercial pharmaceutical products. Looking at the short time of analysis and the low limit detection, we recommend this method for routine assays in the quality control laboratories and as a good method for stability studies of ibuprofen.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.