First Measurements on Triple Oxygen Isotopes of Dissolved Inorganic Phosphate in the Hydrosphere.

Although dissolved inorganic phosphate (DIP) is an important nutrient in the hydrosphere, it is difficult to quantitatively clarify the dynamics of DIP in the hydrosphere using the δO value of DIP as a tracer. In this study, we quantified the triple oxygen isotopic compositions (Δ'O) of DIP relative to VSMOW with the reference line with a slope of 0.528 as an additional tracer to clarify the sources and dynamics of DIP in the hydrosphere.