High performance thin layer chromatographic determination of caffeine in energy drinks and it's corelation with frustration tolerance

High performance thin layer chromatographic (HPTLC) estimation of caffeine was carried out using HPTLC plate (silica gel 60 F254, 20 x 10 cm(2)), solvent system [EtOH- EtOAc, 1: 9 v/v] and scanned at lambda(max) 275 nm. Caffeine exhibited R(f) value of 0.12 +/- 0.01. Validation of the method in terms of linearity, accuracy and precision was carried out. For co-relating caffeine-frustration relationship single group repeated measures were designed for fifty subjects. Analysis of variance indicates that increase in unit dose (100 mg) of caffeine results into statistically significant increase in the frustration tolerance. However, more than 300 mg dose of caffeine showed no further increase in the frustration tolerance of the subjects. Our study reports that energy drinks selected for the study contains caffeine within prescribed WHO limit (300 mg/day).