T01_05

Rapid DIC extraction-to-graphite hybrid system at NOSAMS

Gospodinova K¹,  Gagnon A¹, Wilson J², Hansman R¹, Elder K¹, Burton J¹, Lang S¹, Kurz M¹

¹Woods Hole Oceanographic Institution, Woods Hole, United States, ²AEON Laboratories, Tucson, United States

The Rapid Extraction of Dissolved Inorganic Carbon System (REDICS) is used to provide precise stable isotope and radiocarbon measurements of dissolved inorganic carbon (DIC) at the National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility. For the past year REDICS has primarily been used to provide oceanic radiocarbon measurements for the GO-SHIP program. REDICS automatically extracts sample DIC in the form of CO₂ using a membrane contactor and stores the extracted gas into a glass manifold for subsequent analysis on one of NOSAMS graphitization systems.

NOSAMS recently purchased a carbon extraction and graphitization system (CEGS) from AEON Laboratories, which was customized to automatically process and graphitize ten samples while obtaining sample splits for stable isotope δ¹³C analysis. The system is compact, easily transportable, and, unlike other graphitization systems at NOSAMS, the sample graphitization begins immediately post-sample transfer to the reactor. These characteristics make it ideal for connecting to other CO₂ extraction systems.

Here we present our work on linking the REDICS and CEGS systems to create a hybrid system for rapidly processing DIC from seawater and groundwater samples. The analysis time from extraction to beginning of graphitization is on the order of 35 min, with current output designed for ten samples each day. Linking the two systems not only streamlines the process but shortens it from a two-day analysis to one, further increasing overall sample throughput at the facility.