HEIDELBERG RADIOCARBON LAB – ESTABLISHING A NEW CARBON DIOXIDE EXTRACTION LINE FOR CARBONATE SAMPLES
HEIDELBERG RADIOCARBON LAB – ESTABLISHING A NEW CARBON DIOXIDE EXTRACTION LINE FOR CARBONATE SAMPLES
复制标题
DOI：
10.1017/rdc.2021.28
复制
发表时间：
2021-04
期刊：
影响因子：
8.3
通讯作者：
S. Therre;L. Pross;R. Friedrich;M. Trüssel;N. Frank
中科院分区：
文献类型：
--
作者：
S. Therre;L. Pross;R. Friedrich;M. Trüssel;N. Frank
**摘要** 在古气候研究中，为了从碳酸盐样本的放射性碳（¹⁴C）测年中获得高精度且可重复的结果，海德堡环境物理研究所的海德堡放射性碳实验室设计、建造了一条新的二氧化碳提取线并对其进行了表征。该装置包括一个圆形玻璃管设计，其在10⁻⁵毫巴数量级的真空压力下运行。对提取过程的效率进行了评估，结果表明块状固体样本（99.58 ± 4.69）%的条件明显优于粉末状样本（88.28 ± 10.03）%。过程空白值低于0.2 pMC的表观¹⁴C活性。对国际原子能机构C2标准的重复测量平均值为（41.09 ± 0.23）pMC，证明了该仪器的高精度和可重复性。在一次约2.5小时的运行中，可以处理6个质量为6到12毫克的连续碳酸盐样本。因此，新装置有助于环境物理研究所古气候研究中放射性碳测年结果的高效且可重复。在首次应用中，给出了来自施拉滕洞穴的全新世高山石笋的死碳分数（DCF）值，揭示了大气和石笋¹⁴C之间极高的偏差，DCF值在（49.4 ± 0.4）%和（61.6 ± 0.4）%之间。
ABSTRACT To achieve high-precision and reproducible results from radiocarbon (14C) dating of carbonate samples in paleoclimate research, a new CO2 extraction line was designed, constructed, and characterized at the Heidelberg Radiocarbon Lab of the Institute of Environmental Physics, Heidelberg. The setup includes a circular glass-tube design, which is operated at vacuum pressure levels of the order of 10–5 mbar. The efficiency of the extraction process was assessed, showing significantly favorable conditions for solid piece samples (99.58 ± 4.69)% over powdered samples (88.28 ± 10.03)%. Process blank values are below 0.2 pMC apparent 14C activity. Repeated measurements of IAEA C2 standards with an average value of (41.09 ± 0.23) pMC attest high accuracy and reproducibility of the instrument. Six consecutive samples of 6 to 12 mg carbonate mass can be processed in one run of roughly 2.5 hours. Thus, the new setup contributes to time-efficient and reproducible radiocarbon dating results for paleoclimate research at the Institute of Environmental Physics. In a first application, Dead Carbon Fraction (DCF) values of a Holocene alpine stalagmite from Schratten Cave are presented, revealing extraordinarily high offsets between atmospheric and stalagmite 14C with DCF values between (49.4 ± 0.4)% and (61.6 ± 0.4)%.