1988 Volume 29 Issue 2 Pages 136-140_1
A simple and practical method for the determination of caffeine in coffee, black tea and green tea is described. It is based on the extraction and clean-up of caffeine using an Extrelut column and analysis by means of high performance liquid chromatography with an ultraviolet detector (275nm). A column of Lichrosorb Si60 (silica gel) and H2O-saturated dichloromethane-ethanol (97:3) as a mobile phase are used.
In this method, the average recoveries of caffeine from several samples were 98-102%, the relative standard deviations for the whole procedure were 0.61-7.8%, and the limit of determination for caffeine in sample solution was about 1μg per ml. The proposed method was applied to the determination of caffeine in coffee, canned coffee, black tea and green tea.
