Abstract
By carring out acid-hydrolysis, photo-oxidation and autoclave wet-oxidation for sea water, it became possible to determine some chemical forms of dissolved phosphate to some extent; the concentrations of organic monophosphate and dissolved total phosphate were determined by photo-oxidation and autoclave wet-oxidation, respectively. By combining photo-oxidation with autoclave wet-oxidation, the concentration of dissolved polyphosphate was determined. In addition of acid-hydrolysis to these reactions, it was found that the concentrations of organic and inorganic polyphosphate could be separately evaluated. The above technique was applied to natural sea water and river water near Hiroshima city, and the chemical forms of phosphate measured in these waters were discussed. The determination of the chemical forms of dissolved phosphate is considered to give an important clue for the elucidation of dynamic aspect of phytoplankton in coastal marine.
