Spectrophotometric determination of Caffeine in Nescafe, Cacao, Cappuccino and Coffee samples collected from some Libyan Markets

الملخص

Coffee is one of the most popular beverages that are widely consumed in the world. This study aimed to determine the caffeine in Nescafe, Cacao, Cappuccino, Coffee, using a UV-Visible spectrophotometer. In addition, studied caffeine stability in water. In the presented study, seventeen samples were collected from some Libyan markets. A simple, rapid, and, reliable extraction method for the determination of caffeine in the samples using dichloromethane, n-hexane, and methanol as the extracting solvents. The method is validated over a wide linear range of 2 – 10 μg/ml with correlation coefficients being consistently greater than 0.999. The minimum caffeine level was observed in the Nesquik (Cacao), Nestle Italian S.P.A sample (8.66 μg/ml), while the Nestle (Nescafe), Asbania sample showed the highest caffeine content (461.87ppm).The study of caffeine stability indicates that caffeine is stable in water for more than two weeks.