Thin layer chromatographic method for determining plant pigments in marine particulate matter, and ecological significance of the results

Abstract

Thirty to 100 liters of sea water sample containing MgC03 powder was filtered through a glass fiber filter in order to collect particulate matter. Soon after the filtration, this glass fiber filter was kept in a deep freezer (-20°C) for later use. The following pigment analysis was carried out within a week. Plant pigments in the collected particulate matter were extracted with 90% acetone in a dark refrigerator. Pigments in the acetone extract were separated by thin layer chromatography using a mixture of cellulose powder and soluble starch as an adsorbent. The developing solvent was 1.2% n-propanol in petroleum ether. According to this procedure, 9 kinds of pigments were fractionated. Each of the fractionated pigments was eluted with 90% acetone and determined by measuring fluorescence of the acetone extracts after acidification with a small amount of hydrochloric acid. The analyses of sea water samples from the central Pacific showed the following facts: (1) Vertical distribution of chlorophyll a had a peak at a depth of 100 m or 150m and its amount remarkably decreased with depth in parallel with the total pigments. (2) The percentage of chlorophyll a in the total pigments was more than 60% for the sea water samples examined, even at the depth of 1,000m. (3) The absence of phaeophytin a was made clear for the samples examined. © 1971, GEOCHEMICAL SOCIETY OF JAPAN. All rights reserved.