RICE-W (Radiocarbon Intercomparison on Chemical Experiments, Water series) program; An Examination of the precipitation method

Minami, Masayo*; Takahashi, Hiroshi*; Aramaki, Takafumi*; Kokubu, Yoko   ; Ito, Shigeru*; Nakamura, Toshio*

We have started a Radiocarbon Intercomparison on Chemical Experiments, Water series (RICE-W) program to examine whether carbon isotopic fractionation and carbon contamination occur or not on C analysis of dissolved inorganic carbon (DIC) in water by different sample preparation and storage methods. Eight water samples of four kinds (surface seawater, ground water, hot spring water, and sodium bicarbonate solution) have already analyzed by six AMS laboratories in Japan, and the results obtained are gradually being published. Here, we report the progress of RICE-W program briefly, and then give consideration to the result using the precipitation method, by which DIC is precipitated into SrCO or BaCO, and then oxidized with HPO to extract CO.