HIGH PRECISION 14C ANALYSIS IN SMALL SEAWATER SAMPLES

A new method to extract CO 2 in seawater samples for the determination of F 14 C has been developed in the Laboratory of Ion Beam Physics at ETH Zurich. The setup consists of an automated sampler designed to extract dissolved inorganic carbon (DIC) from 7 samples in a row, by flushing the seawater with He gas to extract CO 2 . The fully automated method is controlled via a LabVIEW program that runs through all consecutive steps: catalyst preconditioning, CO 2 extraction, CO 2 trapping, thermal CO 2 release from the trap into the reactor and finally the graphitization reaction which is performed simultaneously in the 7 reactors. The method was optimized by introducing a Cu-Ag furnace that was placed between the water and zeolite traps, which resulted in a better and faster graphitization performance ( 14 C) as water mass tracer.