Determination of caffeine in energy drinks available at local market using High Performance Liquid Chromatography (HPLC) with Diode Array Detector (DAD) / Nur Atiqah Ahmad

In recent years, the increase consumption of energy drinks has raised concerns among scientific community and public about the health effects of these products that related with its caffeine content. Hence, it is important to efficiently determine the caffeine concentration in the drinks. High Performance Liquid Chromatography (HPLC) method has been developed to determine the amount of caffeine in different brands of energy drink. In this method, the identification and determination of caffeine in energy drinks were carried out under constant flow rates which is 1.6 mL/min and at 272 nm wavelength detector. A mixture of water:acetonitrile (v/v) was used as mobile phase to separate caffeine in Hypersil GOLD CI8 column (25 cm x 4.6 cm x 5 urn). Peaks separation was best achieved using gradient elution of mobile phase within 6.0 min. Both samples and caffeine standard were analysed under the same conditions. Caffeine was detected at 1.9 min for both standard and energy drink samples. The concentration of caffeine in energy drinks was quantified using multiple point external standard method. Calibration curve gave a good correlation coefficient (R2) of 0.9986 while limits of detection (LOD) and quantitation (LOQ) were found to be 4.79 and 14.51 mg/L respectively. The results obtained shows that ED2 had the highest amount of caffeine. It was, however, noted that though most of the energy drinks had high caffeine content they had no label claim.