Compound specific radiocarbon data from sediment core PS51/159-10, western Laptev Sea, Arctic Ocean

Subsample slices thick between 1 and 4 cm were taken from sediment core PS51/159-10 for compound-specific radiocarbon analysis (CSRA) for terrestrial biomarkers. The subsample intervals were selected based on downcore variations in biomarker contents (Lin et al., 2025), to correspond to periods of rapid and little terrestrial organic matter mobilizations during the early last deglaciation and the Holocene. Target compounds include mid-chain (n-C23, n-C25) n-alkanes, high molecular weight (HMW, or long-chain) (n-C29, n-C31) n-alkanes, and HMW (n-C28:0) fatty acid. Lipid extractions and purifications for CSRA followed the procedure described in Winterfeld et al. (2018). Radiocarbon measurements on isolated compounds were conducted on samples containing a minimum of 40 µg C using a Mini Carbon Dating System (MICADAS), following the method described in Mollenhauer et al. (2021). CSRA values were reported as F14C, which were corrected for carbon introduced during methylation (Douglas et al., 2014) and processing blanks (Wacker and Christl, 2011). Processing blanks were assessed by analyzing modern and fossil laboratory standards processed alongside the samples, following Sun et al. (2020). The estimated background introduced during processing contained 5.5 ± 0.5 μg C with F14C = 0.7632 ± 0.0394 for n-C28:0 fatty acid measurements, and 2.4 ± 0.2 μg C with F14C = 0.3671 ± 0.0296 for n-alkane measurements.