HPTLC determination of caffeine in stimulant herbal products and power drinks.

摘要

The caffeine content of selected herbal products and energy drinks available in the Saudi market was determined by HPTLC-UV densitometric analysis. Pre-coated HPTLC silica gel plates (20cm x 10cm) were used for the analysis. The solvent system consisted of ethyl acetate-methanol (85:15, v/v), and caffeine was detected at 275nm. The developed method was validated for specificity, repeatability (C.V. < 5%), recovery (98.90 +/- 3.46), and accuracy (99.84 +/- 2.87). The levels of caffeine were 4.76-13.29% (w/w) and 0.011-0.032% (w/v), for the herbal products and the energy drinks, respectively.