The caffeine content in energy drinks ranges from 6 to 242 mg per servings according to a consumer report findings in 2012.

caffeine ratings

A series of caffeine standards will be prepared to develop a calibration curve. The amount of caffeine in the Red Bull sample will then be analyzed from the least square analysis of the calibration curve. The structure of caffeine is shown below (Fig. 1) along with its UV absorption spectrum (Fig. 2). In HPLC, we chose the λ_max of the analyte (273 nm for caffeine) to detect the peak. In the event, that the λ_max is not found, a common wavelength for the detection of organic molecules is 254 nm and 280 nm for proteins.

caffeine molecule

Fig. 1

caffeine UV absorption spectrum

Fig. 2