This effect is also clearly seen in the spectral
bands of caffeine in coffee seeds (Fig. 5) dissolved in water.
Hence, it is not suitable to determine the percentage of caffeine
in coffee seeds due to overlapping of these interfering
bands. In order to overcome this difficulty coffee was first
dissolved in water and caffeine extracted from solution
using dichloromethane. Dichloromethane is the most commonly
employed method for extraction of caffeine from
green coffee beans