PO14C dating of glacier ice – recent improvements for an easier device handling

Over the last 15 years, studies of non-polar ice core archives have successfully demonstrated the usefulness of ice core dating via 14C in particular organic carbon (PO14C). It excels especially in deeper layers, where stratigraphic dating methods cannot be applied. This presentation focuses on improvements made to the PO14C inline filtration-oxidation unit (REFILOX) system developed by Hoffmann et al. (2017, Radiocarbon, doi:10.1017/RDC.2017.99), which has been successfully applied in several Alpine ice core studies (e.g. Legrand et al. 2025, PNAS Nexus, doi:10.1093/pnasnexus/pgaf186). The device was redesigned to allow an easier handling by avoiding the fragile, difficult to obtain and expensive quartz glass to stainless steel passages of the device. In addition, the material of the combustion chamber was changed to borosilicate glass, which is much easier to handle compared to quartz glass. Combined, these changes allow a faster and more thorough cleaning and assembly process. We introduce the new key characteristics of the modified setup, which already showed that the process blank could be maintained in the sub-microgram range. Beside blank characteristics and precision compared to standard material, a first application of the improved system is presented demonstrating its potential for radiocarbon dating of real glacier ice samples.