Browsing by Author "G/medhin Tesfay"

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    Photo physical properties of Caffeine and cu (ii)-caffeine Complex
    (Addis Ababa University, 2007-09) G/medhin Tesfay; Asfaw Araya (PhD)
    In this thesis UV/Vis absorption spectra of caffeine in water and dichloromethane, copper sulphate, and mixture of caffeine and copper sulphate in water solution is investigated. UV/Vis absorption spectrum of Cu (II)-Caffeine complex is also investigated as a function of time during refluxing to check complex formation. The molar decadic absorption coefficient of caffeine is calculated. Fluorescence emission spectra of Cu (II)- Caffeine complex is also investigated and compared with its absorption band. Area normalization analysis method is used. Finally, a better derivative fluorescence method for determination of caffeine content of substances is recommended Key words: Absorbance, Molar decadic absorption coefficient, Reflux, Complex formation, Derivative Fluorescence, Is-emission point, Area normalization