Fleisher Adam J, Long David A, Liu Qingnan, Gameson Lyn, Hodges Joseph T
National Institute of Standards and Technology , 100 Bureau Drive, Gaithersburg, Maryland 20899, United States.
J Phys Chem Lett. 2017 Sep 21;8(18):4550-4556. doi: 10.1021/acs.jpclett.7b02105. Epub 2017 Sep 11.
High-precision measurements of radiocarbon (C) near or below a fraction modern C of 1 (FC ≤ 1) are challenging and costly. An accurate, ultrasensitive linear absorption approach to detecting C would provide a simple and robust benchtop alternative to off-site accelerator mass spectrometry facilities. Here we report the quantitative measurement of C in gas-phase samples of CO with FC < 1 using cavity ring-down spectroscopy in the linear absorption regime. Repeated analysis of CO derived from the combustion of either biogenic or petrogenic sources revealed a robust ability to differentiate samples with FC < 1. With a combined uncertainty of C/C = 130 fmol/mol (FC = 0.11), initial performance of the calibration-free instrument is sufficient to investigate a variety of applications in radiocarbon measurement science including the study of biofuels and bioplastics, illicitly traded specimens, bomb dating, and atmospheric transport.
对分数现代碳（C）接近或低于1（FC≤1）时的放射性碳进行高精度测量具有挑战性且成本高昂。一种准确、超灵敏的线性吸收法检测碳，将为现场外加速器质谱设施提供一种简单且可靠的台式替代方案。在此，我们报告了使用线性吸收区域的光腔衰荡光谱法对FC<1的CO气相样品中的C进行定量测量。对源自生物源或石油源燃烧产生的CO进行重复分析，结果显示该方法具有强大的区分FC<1样品的能力。在C/C的合成不确定度为130 fmol/mol（FC = 0.11）的情况下，这种免校准仪器的初始性能足以研究放射性碳测量科学中的各种应用，包括生物燃料和生物塑料研究、非法交易标本、核弹年代测定以及大气传输研究。
