Vertical distribution of pigments in a lake sediment as determined by paper chromatography

抄録

Paper chromatographic determination has been studied for plant pigments in core samples from Lake Kizaki-ko (maximum depth: 28.5 m, area: 1.413 km²). Eleven kinds of pigments were fractionated and determined by this method, and are called fractions No. 1 through No. 11 in order of their Rf values. Nos. 1 through 3 correspond to carotenoids, No. 4 to phaeophytin a, No. 6 to chlorophyll a, and other fractions to chlorophyll derivatives. Total amount of the pigments remarkably decreases with core depth from surface down to 20 cm, and remains practically uniform in deeper layers. Among the pigments, fractions No. 4 (phaeophytin a), No. 6 (chlorophyll a) and No. 11 are predominant with 159, 445, and 125 ppm as of dry samples respectively in surface sediments. Their concentrations strikingly decrease with depth in the upper layers from 74, 98, and 63 pprn at a depth of about 5 cm to 14, 6.7, and 12 ppm respectively at a depth of about 20 cm. Vertical distribution of various pigments as indicated by their percentage in total pigments shows that the net-decomposition rate (decomposition rate—production rate) of each pigment in the sediments is in the following order: Chlorophyll a (No. 6) > No. 8 > No. 1, No. 2, No. 3 > Phaeophytin a (No. 4), No. 11, No. 9, No. 10, No. 7 > No. 5.