Quantification of Caffeine in Energy Drinks and Carbonated Beverages Retailed to Students in Ile-Ife, Osun State

Caffeine is a widely consumed psychoactive stimulant found in significant concentrations in energy drinks and carbonated soft drinks. The increasing popularity of these beverages among Nigerian university students raises public health concerns about excessive caffeine intake, particularly given inconsistent or absent labelling of actual caffeine content. This study quantified caffeine concentrations in twelve energy drink and carbonated beverage brands commonly purchased by students in Ile-Ife, Osun State, South West Nigeria. UV-Visible spectrophotometry at 273 nm and HPLC with UV detection were both employed, and results were compared with declared values where available. Mean caffeine concentrations ranged from 18 to 162 mg per 250 ml serving. Three energy drink brands contained caffeine levels exceeding the 200 mg per serving threshold considered potentially harmful by the European Food Safety Authority. Label claims were accurate within 10% for only five of the twelve products. Carbonated cola beverages contained lower but consistent caffeine levels. Students in focus groups reported consuming multiple servings daily. The study concludes that energy drinks widely available to students in Ile-Ife contain caffeine at pharmacologically significant levels with inadequate labelling transparency. Regulatory action to mandate clear caffeine labelling and enforce maximum caffeine content standards is recommended. Keywords: caffeine, energy drinks, HPLC, spectrophotometry, Ile-Ife.