Determination of Caffeine Content in Non-Alcoholic Beverages and Energy Drinks Using Hplc-Uv Method.

Abstract

The purpose of this study was to determine the amount of caffeine in non-alcoholic energy drinks and prepared teas using reverse phase HPLC. Caffeine was extracted from 19 different types of non-alcoholic beverages and prepared teas sampled from supermarkets in Nairobi Central Business District, Kenya. These were analyzed alongside a caffeine standard of 99 % purity by use of HPLC-UV detector at the wavelength of 272nm, Supelco HS C18 column 25 cm x 4.6 cm x 5 μm, oven temperature of 40 oC, mobile phase 80:20 (v/v) of methanol: water and mobile phase flow rate of 1.5mL/min. For quantitation purposes, serial dilution of the caffeine standard gave correlation coefficient (r) of 0.9993 and the retention time of 2.11±0.03 minute. Percentage recovery of caffeine from the column ranged from 89.78 to 105.59%. Limits of detection and quantitation were found to be 0.279 and 0.931 μg/mL respectively. It was found that Burn®, XL energy drink® and Red Bull® had the highest amount of caffeine. It was however noted that though most of the non-alcoholic beverages had high caffeine content they had no label claim. Key Words: Reverse Phase High Performance Liquid chromatography (HPLC), Ultra violet visible (UV/VIS), caffeine, non-alcoholic beverages