| 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100ml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： |
| 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） |
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| Effect of blank sample calibration on the determination of particulate organic carbon in ocean by elemental analyzer |
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liuyi, zhang jihong, wu wenguang, sun ke, yang jun, liu yue, jiang yafei
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Yellow Sea Fisheries Research Institute
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| Abstract: |
| Particulate organic carbon (POC) plays an important role in the marine ecosystem and even the global carbon cycle, accurate acquisition of relevant data is a key link in research on marine carbon cycle. The elemental analyzer is the most commonly used method for accurately determining POC. However, the impact of dissolved organic carbon (DOC) in water is often ignored during sampling. For how to obtain blank samples to effectively remove the impact of DOC, in this paper, we investigated the impact of filter membranes on the data and designed five different sampling methods to compare the effects of various sampling methods on the data. The results show that 1) The blank values obtained by different blank sample acquisition methods are significantly different, and the offset error is not corrected by blank correction. 2) Both the literature and the blank sampling method designed in this paper have abnormalities where the blank value is greater than the sample value. 3) 100ml of artificial seawater can be filtered to effectively remove the adsorbed DOC. 4）After burning at 450 ℃ for 5 hours, the carbon adsorbed on the filter can be effectively removed, but the longer the storage time, the more likely the filter will adsorb carbon from the air. The method identified in this study can effectively remove the impact of DOC on the measurement results, supplement and improve the influencing factors not considered in the national standard, The method can effectively remove the influence of DOC on the measurement results, and have high repeatability and high precision, can be accurately and reliably used for the determination of POC samples. |
| Key words: Elemental analyzer Particulate organic carbon Dissolved organic carbon Blank sample |