Abstract
The popularity of energy beverages among young adult population is high. These drinks are claimed to boost energy and performance and contain high concentration of caffeine as one of the several ingredients. Discrepancies have been encountered by some of the previous studies between the actual quantity of caffeine present in the product and the amount mentioned on the label, making the determination of caffeine content in these drinks very important. Thus, in this study, we analyzed the caffeine concentration in most popular energy drinks available in Saudi Arabia. The energy drink samples (n = 9) were procured from retail outlets. Sample solutions were prepared in methanol and analyzed for caffeine content by GC-MS. Chromatographic parameters were optimized to achieve optimum resolution and various validation parameters were evaluated. The method was successfully applied for the quantification of caffeine in energy drinks by directly injecting the multifold diluted samples in methanol. The method was linear (r(2) = 0.999) over a concentration range of 5-25 mu g/mL, specific, precise (%RSD of peak area = 0.56-0.78), and accurate (%recovery = 99.3-101.2%). The amounts of caffeine determined were found in the range of 20.82-33.72 mg/100 mL (52.05-84.3 mg/pack). Results revealed that the amount of caffeine actually present in the tested drinks varied within +/- 10% range from the amount specified on the product labels. The amounts of caffeine detected in tested beverages were within the USFDA safe upper limit of per-day caffeine consumption, which has indicated that the consumption of one serving of energy drink is unlikely to produce any adverse health effect.