Development and Validation of Ultra Performance Liquid Chromatography (UPLC) Method for the Quantitative Estimation of Caffeine in Non-Alcoholic Soft and Energy Drinks

Abstract Background The popularity of beverages such as cold coffee, iced tea, and energy drinks has risen tremendously among athletes and youths. Energy drinks are used to enhance performance due to the presence of a high amount of caffeine (CFN) and sugars, as well as other constituents such as vitamins, amino acids, taurine, extracts of Ginkgo biloba, ginseng, guarana, and other herbal products. Commercial drinks are promoted as being beneficial to health; thus it is an important concern regarding adverse effects linked with these drinks or products. Objective The aim of the study is to develop and validate the ultra performance liquid chromatography-photodiode array detector (UPLC-PDA) method for the estimation of CFN in eight marketed non-alcoholic drinks including two soft drinks and six energy drinks. Method The chromatographic separation of CFN was achieved on Acquity UPLC® CSHTM C18 1.7 µm, 2.1 × 100 mm column, using isocratic mode, mobile phase comprising acetonitrile and water (30:70, v/v) at a flow rate 0.3 mL/min using injection volume 1 µL. Results The elution of CFN occurred at 1.06 min, and the calibration curve of the CFN was computed from the peak area ratio detected at 273 nm. All the validation parameters were found within the assay variability limits as per ICH guidelines. The obtained results revealed that the soft drinks SD1 and SD2 have 87.21 ± 1.28 and 101.81 ± 1.52% (w/w), whereas CFN concentration in energy drink brands ED1, ED2, ED3, ED4, ED5, and ED6 was 95.90 ± 1.62, 64.0 ± 1.07, 76.68 ± 1.95, 74.97 ± 2.33, 82.09 ± 2.43, and 88.04 ± 2.94% (w/w) of labeled claims, respectively. Conclusions The developed UPLC method was found suitable for the quality control of commercial soft and energy drinks containing CFN. Highlights The developed chromatographic method is very simple, cost effective and could be utilized for the routine analysis of caffeine in the soft and energy drinks.