刘毅^1,2,3, 刘群², 吴文广¹, 杨珺¹, 刘越^1,4, 姜雅斐^1,4, 张继红^1,5
1.中国水产科学研究院黄海水产研究所 农业农村部海洋渔业资源可持续利用重点实验室, 山东 青岛 266071;2.中国科学院 海洋研究所 海洋生态与环境科学重点实验室, 山东 青岛 266071;3.中国科学院大学, 北京 100049;4.大连海洋大学 水产与生命学院, 辽宁 大连 116000;5.青岛海洋科学与技术国家实验室 海洋渔业科学与食物产出过程功能实验室, 山东 青岛 266000

摘要:
颗粒有机碳（POC）在海洋生态系统乃至全球碳循环中发挥着重要作用，其准确获取至关重要。目前，元素分析仪测定POC是最准确和常用的分析方法，但取样忽略了水体溶解有机碳（DOC）可能带来的影响。针对空白样品如何获取才能有效去除DOC影响的问题，本文设计比较了5种取样方法对POC测定结果的影响，以及滤膜对数据的影响。结果显示，1）5种样品取样方法所得的结果差异显著，不进行空白校正会对结果产生较大误差；2）文献和本文设计的空白样取样方法均出现了空白值大于样品值的异常情况；3）样品继续抽人工海水100 mL即可有效洗去滤膜上吸附的DOC；4）未过滤的滤膜450℃灼烧5 h后可以有效去除滤膜上吸附的碳，但是存放时间越久滤膜从空气中吸附碳的概率越大。本研究确定的人工海水法可以有效去除DOC对测定结果的影响，样品测定结果重复性、精密度高，可准确用于海水POC样品的测定。
关键词:元素分析仪颗粒有机碳溶解有机碳空白样品
DOI：10.11759/hykx20200221001
分类号:O656.32;P734.4
基金项目:中国水产科学研究院黄海水产研究所基本科研业务费资助（20603022019012）；国家自然科学基金项目（U1906216）；国家虾蟹产业技术体系（CARS-48）

Effects of different sampling methods on the accuracy of particulate organic carbon and particulate nitrogen samples in ocean
LIU Yi^1,2,3, LIU Qun², WU Wen-guang¹, YANG Jun¹, LIU Yue^1,4, JIANG Ya-fei^1,4, ZHANG Ji-hong^1,5
1.Key Laboratory for Sustainable Development of Marine Fisheries, Ministry of Agriculture/Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Science, Qingdao 266071, China;2.Key Laboratory of Marine Ecology and Environmental Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China;3.University of Chinese Academy of Sciences, Beijing 100049, China;4.College of Fisheries and Life Science, Dalian Ocean University, Dalian 116000, China;5.Function Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology(Qingdao), Qingdao 266000, China
Abstract:
Particulate organic carbon (POC) plays an important role in both the marine ecosystem and the global carbon cycle, and the accurate acquisition of relevant data is a key factor in research on the marine carbon cycle. Elemental analysis is the most commonly used method for accurately determining POC content. However, the impact of dissolved organic carbon (DOC) in water is often ignored during sampling. In this study, we focused on how to obtain blank samples and effectively remove the impact of DOC. We investigated the impact of the use of filter membranes on the data and designed five different sampling methods to compare their effects on the data. The results show that:1) the blank values obtained by different blank sample acquisition methods differ significantly, and their offset errors are not corrected by blank correction. 2) Both the methods reported in the literature and the blank sampling methods designed in this study produced abnormalities in which the blank value was greater than the sample value. 3) 100 ml of artificial seawater can be filtered to effectively remove the adsorbed DOC. 4) After heating at 450℃ for 5 h, the carbon adsorbed on the filter can be effectively removed, but the longer is the storage time, the more likely is the filter to adsorb carbon from the air. The method developed in this study can effectively remove the impact of DOC on the measurement results, and supplement and improve the factors of influence that are not considered in the national standard. The proposed method can effectively remove the influence of DOC on the measurement results, exhibits high repeatability and high precision, and can be accurately and reliably used for the determination of POC samples.
Key words:Elemental analyzerparticulate organic carbondissolved organic carbon blank sample





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