Quantitative Analysis of Caffeine in Carbonated Beverages from the Bangladeshi Market Using Spectroscopy methods

This study explores the caffeine content in popular beverages using UV-visible spectroscopy as a cost-effective and accessible analytical method. Caffeine, a naturally occurring alkaloid, is widely consumed for its central nervous system stimulant properties, with sources including coffee, tea, and energy drinks. The analysis involved caffeine extraction using dichloromethane, followed by UV spectroscopy measurement at 260 nm, demonstrating a strong linear relationship (R² > 0.99) between absorbance and concentration. Among the tested beverages, Red Bull exhibited the highest caffeine content per serving (52.5 mg), followed by Nescafe (45 mg) and Tiger (25.5 mg), while Coca-Cola and Mojo had the lowest levels (21 mg each). Comparative data from published sources confirmed variations in caffeine content, with Stings (160 mg) and Red Bull (80 mg) leading in published caffeine data. Statistical analysis revealed weak negative correlations between total sample volume and caffeine content per serving (-0.456, p = 0.185) and per milliliter (-0.426, p = 0.220), suggesting inconclusive relationships. The findings underscore the significance of consumer awareness and regulatory measures for caffeine labeling, particularly for high-caffeine products like energy drinks. This study highlights UV-visible spectroscopy as an effective alternative to more resource-intensive methods for caffeine quantification in beverages.