A toc system for the analysis of the d13c signature of estuarine and marine dissolved organic carbon

用于分析河口和海洋溶解有机碳的 d13c 特征的 TOC 系统

• 批准号: 390955-2010
• 负责人: Gélinas, Yves
• 金额: $ 4.12万
• 依托单位: Concordia University
• 依托单位国家: 加拿大
• 项目类别: Research Tools and Instruments - Category 1 (<$150,000)
• 财政年份: 2009
• 资助国家: 加拿大
• 起止时间: 2009-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=443334
• 关键词: toc; system; analysis; d13c; signature

The stable isotope composition of dissolved organic carbon (d13C-DOC) provides powerful information towards understanding carbon sources and cycling, but analytical limitations have precluded its routine measurement in natural estuarine and seawater samples. The methods employed to measure d13C-DOC in marine samples tend to be long and tedious usually requiring highly specialized, expensive equipment, large sample volumes, and a number of steps to remove carbonates and quantitatively convert DOC into CO2 for eventual off-line analysis by mass spectrometry. Recent interfacing of wet oxidation-based dissolved organic carbon analyzers and isotope ratio mass spectrometers has simplified the measurement of d13C-DOC in freshwaters, but the analysis of salty estuarine/marine samples still proves difficult. We have successfully coupled the a high-temperature catalytic oxidation-based total organic carbon analyzer to an isotope ratio mass spectrometer (HTC-IRMS) through cryogenic trapping of analyte gases exiting the HTC analyzer for routine analysis of d13C-DOC in estuarine and marine samples (Panetta R.J., Ibrahim M., Gélinas, Y. (2008) Anal. Chem. 80, 5232-5239). We are one of the very few laboratories in the world currently capable of routinely measuring samples over the natural range of DOC concentrations (from 35 µM to over 2000 µM), and salinities (<0.1 to 36 g/kg) encountered in the environment, with excellent d13C-DOC accuracy (± 0.2 per mil) and precision (± 0.3 per mil).

溶解有机碳（d13 C-DOC）的稳定同位素组成为理解碳源和循环提供了强有力的信息，但分析的局限性阻碍了其在天然河口和海水样品中的常规测量。用于测量海洋样品中的d13 C-DOC的方法往往是长时间和繁琐的，通常需要高度专业化的，昂贵的设备，大的样品体积，和一些步骤，以去除碳酸盐和定量地将DOC转化为CO2，最终通过质谱法进行离线分析。湿氧化溶解有机碳分析仪和同位素比质谱仪最近的接口简化了淡水中d13 C-DOC的测量，但咸河口/海洋样品的分析仍然很困难。我们已经成功地将基于高温催化氧化的总有机碳分析仪与同位素比质谱仪（HTC-IRMS）耦合，通过对离开HTC分析仪的分析物气体进行低温捕获，用于河口和海洋样品中d13 C-DOC的常规分析（Panetta R. J.，Ibrahim M.，热利纳斯岛（2008）Anal. 80，5232-5239）。我们是目前世界上极少数能够常规测量环境中DOC浓度（从35 µM到2000 µM以上）和盐度（<0.1到36 g/kg）自然范围内的样品的实验室之一，具有出色的d13 C-DOC准确度（± 0.2/mil）和精密度（± 0.3/mil）。