Determination of Chlorophyll in Tea

For determining chlorophyll-a and -b in made tea or tea leaf, the following experiments were performed.1. To extract chlorophyll completely from made tea, three or more successive extractions with acetone containing 10% water were necessary, but when the sample was fresh leaf, undild. acetone should be used at the first time and never had to give heating before extraction, unless otherwise the decomposition of chlorophyll could not be avoided.2. By circular paper chromatography of the acetone extract with the mixed solvents of petroleum ether : benzene (4 : 1) or benzene : carbon tetrachloride : ether (10: 10 : 1), chlorophyll-a, -b, carotenoids and two unidentified pigments were separated clearly, and these pigments could be eluted by ether.3. The ether solution of chlorophyll was estimated by measuring the optical density with a spectral monochromate near 660 mμ. The measurement was greatly interfered by the unidentified pigments but not by the carotenoids.4. The two unidentified pigments which were contained in an appreciable quantity in made tea seemed to be the degradation pro-ducts of chlorophyll-a, and -b whose absorption spectra agreed well with those of phaeophorbide-a, and -b and the color was greyish green and yellowish green respectively.5. In Gyokuro, some amounts of chloro-phyll-a and -b were contained, but in Seneha and pan-parched tea a trace of chlorophyll-a and a small amount of chlorophyll-b. were merely detected and in black tea both chlorophyll-a and -b completely disappeared.It was presumed that the fresh green color of Gyokuro and.Tencha was due to the undecomposed chlorophyll but the dark green color of Sencha and pan-parched tea was characterized by the phaeophorbide-like pigments.