Abstract：
Understanding the distribution of halogenated organic compounds (HOCs) in marine sediments is essential for understanding the marine carbon and halogen cycling, and also important for assessing the ecosystem health. In this study, a method based on combustion-ion chromatography was developed for determination of the composition and abundance of HOCs in marine sediments. The method showed high accuracy, precision and reproducibility in determining the content of adsorbable organic halogens (AOX), including fluorine, chlorine and bromine (AOF, AOCl, AOBr) and the corresponding insoluble organic halogens (IOF, IOCl, IOBr, IOX), as well as total organic halogen contents (TOX). Application of the method in coastal and deep-sea sediments revealed high ratios of organic halogens in the organic carbon pool of marine sediments, suggesting that organic halogen compounds represent an important yet previously overlooked stock of carbon and energy in marine sediments. Both the TOX and the proportion of organohalogens in organic carbon (X:C ratio) showed an increasing trend from the coast to the deep-sea sediments, indicating an increased significance of HOCs in deep-sea environments. The developed method and the findings of this study lay the foundation for further studies on biogeochemical cycling of HOCs in the ocean.
摘要：
了解海洋沉积物中卤化有机化合物（HOC）的分布对于了解海洋碳和卤素循环至关重要。对评估生态系统健康也很重要。在这项研究中,建立了一种基于燃烧-离子色谱法的海洋沉积物中HOCs的组成和丰度测定方法。该方法准确度高,测定可吸附有机卤素（AOX）含量的精密度和重现性，包括氟,氯和溴(AOF，AOCl,AOBr)和相应的不溶性有机卤素(IOF，IOCl,IOBR,IOX),以及总有机卤素含量（TOX）。该方法在沿海和深海沉积物中的应用表明，海洋沉积物的有机碳库中有机卤素的比例很高，这表明有机卤素化合物代表了海洋沉积物中重要但以前被忽视的碳和能源存量。从海岸到深海沉积物，TOX和有机碳中有机卤素的比例（X：C比）均呈增加趋势，表明深海环境中HOC的重要性增加。所开发的方法和研究结果为进一步研究海洋中HOCs的生物地球化学循环奠定了基础。
