Performance evaluations and applications of a δ13C-DIC analyzer in seawater and estuarine waters
Performance evaluations and applications of a δ13C-DIC analyzer in seawater and estuarine waters
复制标题
海水和河口水域中Ύ´13C-DIC分析仪的性能评估和应用
DOI：
10.1016/j.scitotenv.2022.155013
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发表时间：
2022
影响因子：
9.8
通讯作者：
Cai, Wei-Jun
中科院分区：
文献类型：
--
作者：
Deng, Xue;Li, Qian;Su, Jianzhong;Liu, Chun-Ying;Atekwana, Eliot;Cai, Wei-Jun
溶解无机碳（DIC）及其稳定同位素（δ 13 C-DIC）是研究水环境碳循环的重要参数。基于同位素比质谱仪的传统方法是劳动密集型的，并且不容易在现场部署。在这里，我们报告的方法，同时测量DIC浓度和其稳定同位素的性能，通过使用CO2提取装置和腔衰荡光谱（CRDS）检测器。多通阀用于增加样品通量和提高精度。对于海水中的DIC和δ 13 C-DIC，仪器的平均精密度分别优于±1.95 μmol kg− 1和±0.06‰（每个样品进样3次）。通过考察进样体积和浓度效应，对不同类型沃茨中DIC含量范围较大的δ 13 C-DIC样品的精确测定提出了建议。该技术被应用于研究碳循环在特拉华州河口。这表明，同时精确测定DIC和δ 13 C-DIC是制约水体碳循环和CO2通量控制过程的有力和有效的方法。实验室测试和现场应用都证实了该系统可以高精度地用于研究各种水环境中的碳循环。
Dissolved inorganic carbon (DIC) and its stable isotope (δ13C-DIC) are important parameters for studying carbon cycling in aquatic environments. Traditional methods based on isotope-ratio mass spectrometers are labor-intensive and not easily deployable at field sites. Here we report the performance of a method that simultaneously measures DIC concentration and its stable isotope by using a CO2extraction device and a Cavity Ring-Down Spectroscopy (CRDS) detector. A multi-port valve is used to increase sample throughput and improve precision. The instrument achieves average precisions of better than ±1.95 μmol kg−1and ±0.06‰, respectively, for DIC and δ13C-DIC in seawater based on three injections for each sample. We also provide recommendations on how to precisely determine δ13C-DIC samples with a wide range of DIC content in different types of waters by examining injection volume and concentration effects. This technique was applied to study carbon cycling in the Delaware Estuary. It demonstrates that a simultaneous and precise determination of both DIC and δ13C-DIC is a powerful and effective approach for constraining the processes controlling aquatic carbon cycling and CO2fluxes. Both laboratory tests and field applications confirmed that this system can be used with high precision to study carbon cycling in various aquatic environments.