Near Infrared Spectra of Caffeine and its Related Compounds and their Application to Determination of Caffeine Content in Green Tea

Abstract

Near infrared reflectance spectra of caffeine and its related compounds such as xanthine, theophylline and theobromine were studied in connection with their chemical structures. A major difference in the spectra was characterized with a difference in the number of CH3 groups contained in the compounds. It has been verified that the near infrared reflectance spectroscopy can be applied to the quantitative analysis of caffeine in green tea.