Kattein, Laura; Höhn, Malte; Grotheer, Hendrik; Gentz, Torben; Mollenhauer, Gesine: Developing a method for Ramped Pyrolysis/Oxidation-14CO2-analysis at the Alfred Wegener Institute, Bremerhaven: experimental data for method validation, blank determination and data reproducibility [dataset]. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.992009 (dataset in review)

Ramped pyrolysis/oxidation (RPO) is a method that separates sedimentary organic matter fractions based on their thermochemical stability and enables the 14C-analysis of the individual fractions. A system for RPO was set up at the 14C-dating facility of the Alfred Wegener Institute in Bremerhaven. RPO analyses are conducted with a modified SoliTOC Cube Carbon Analyzer (manufacturer Elementar Analysensysteme, Germany), the produced CO2 is trapped on molecular sieve (zeolite) traps and 14C analyses are conducted with the accelerator mass spectrometer Mini Carbon Dating System (MICADAS; Ionplus, Switzerland). This dataset comprises results from multiple laboratory experiments conducted to develop and validate the RPO method. Experiments include the quantification of total organic carbon and validation of a factor derived to convert the area under the CO2 curve (in arbitrary units) into µgC using three certified reference materials. The shapes of the temperature-dependent CO2 evolution (a so called "thermogram") in different operation modes (pyrolysis and oxidation) were compared. Further, the time-dependent procedural blank was investigated by comparing the thermograms of empty SoliTOC runs with the ones of empty, pre-combusted crucibles and trapping the CO2 of two different standard materials (Phthalic Anhydride and Oxalic Acid II) for different amounts of times. The time-independent blank was calculated using a Bayesian statistical model on a series of 14C analyses of Phthalic Anhydride and Oxalic Acid II. The blank correction method was validated by applying it to 7 fractions of a sediment with known 14C content. In addition, the C loss from the zeolite traps was investigated by trapping CO2 and then flushing the traps for various amounts of time. Repeat 14C analyses of the CO2 fractions of the same sediment collected at the same temperatures were conducted. Finally, the reproducibility of the thermograms was analyzed by conducting extensive replicate measurements of three different sample types.