| Abstract: | Chlorophyll pigments in 100% mrthanol extracts from ten axenic cultured diatoms and three green algae were examined using reverse phase HPLC with Jluoromelric detector and field desorption mass spectrometry to identify same unknown peaks tn HPLC chromatograms from natural phytoplankton samples. Characteristics of the HPLC chromatograms were the presence of chlorophyllide and two unknown peaks. Field desorption mass spectrometry of the oxidation products of authentic chlorophyll a suggested that the peaks were due to 10-hydroxy and 10-hydroxy lactone chlorophylls a and 10-methoxy and 10-methoxy lactone chlorophylls a fanned during each process of filtration, storage at -20°C and extraction in methanol. The present results indicated that a new type of chlorophyll c derivative may exist and, as far as we use filtration to collect phytoplankton and store the sample under air even at -20°C, the formation of oxidation products of chlorophyll pigments may he unavoidable. |
