极地研究

极地研究 ›› 2023, Vol. 35 ›› Issue (3): 362-370.DOI: 10.13679/j.jdyj.20220403

• 研究论文 • 上一篇    下一篇

两种无机碳去除方法对南极海洋沉积物中铁结合态有机碳测定的影响

黄文浩1,2  赵军1,2  郭晓泽3  郭佳莹1,2  李栋1,2  潘建明1,2
  

  1. 1自然资源部海洋生态系统动力学重点实验室, 浙江 杭州 310012;
    2自然资源部第二海洋研究所, 浙江 杭州 310012;
    3浙江大学地球科学学院环境与生物地球化学研究所, 浙江 杭州 310027
  • 出版日期:2023-09-30 发布日期:2023-09-30
  • 通讯作者: 赵军
  • 作者简介:黄文浩, 男, 1998年生。硕士研究生, 主要从事南极海洋生物地球化学研究。E-mail: a199878515@163.com
  • 基金资助:

    国家自然科学基金(41976228)、中央级公益性科研院所基本科研业务费专项资金(JG1805, JG2011)和国家海洋局极地考察办公室项目(IRASCC 01-01-02, 02-02)资助

Effects of two inorganic carbon removal methods for determination of reactive-iron-bound organic carbon in Antarctic marine sediments

Huang Wenhao1,2, Zhao Jun1,2, Guo Xiaoze3, Guo Jiaying1,2, Li Dong1,2, Pan Jianming1,2   

  1. 1Key Laboratory of Marine Ecosystem Dynamics, Ministry of Natural Resources, Hangzhou 310012, China;
    2Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China;
    3Institute of Environmental and Biogeochemistry (eBig), School of Earth Sciences, Zhejiang University, Hangzhou 310027, China
  • Online:2023-09-30 Published:2023-09-30

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摘要：

海洋沉积物中活性铁(FeR)结合态有机碳(OC-Fe)具有长期保存潜质, 准确测定其含量对评价其对碳埋藏的贡献(fOC-Fe)和在缓解全球变暖中的作用具有重要意义。目前尚无研究评估酸蒸法和酸洗法对估算OC-Fe和fOC-Fe的定量差异。本研究使用酸蒸法和酸洗法分别对南极普里兹湾5个表层沉积物的原样、还原实验后样品和对照实验后样品进行无机碳去除处理, 测定对应的有机碳(OC)含量, 计算这两种方法的OC-Fe和fOC-Fe。结果表明, 对于原样、对照和还原实验后样品, 酸洗法测得的OC含量比酸蒸法分别低34.82%±12.92%、32.80%±15.11%和26.15%±20.51%, 说明酸洗法能显著析出酸溶性OC和水溶性OC。两种方法处理后得到的OC-Fe含量和fOC-Fe范围均差异显著, 表明酸洗法会额外析出部分高结晶度态铁氧化物或低活性含铁硅酸盐结合的OC, 放大fOC-Fe的差异, 不利于准确评估OC-Fe对海洋沉积OC贡献量。因此, 在开展OC-Fe研究时, 建议采用酸蒸法去除无机碳。

关键词:

海洋沉积物, 有机碳, 活性铁, 酸洗法, 酸蒸法


Abstract: The reactive-iron (FeR)-bound organic carbon (OC-Fe) in marine sediments has long-term preservation potential. Accurate determination of OC-Fe content is essential to evaluate its contribution to carbon sequestration (fOC-Fe) and to global warming. Quantitative differences between the fumigation and rinse methods, applied to estimate the OC-Fe and fOC-Fe, have not previously been assessed. In this study, the fumigation and rinse methods were used respectively to remove inorganic carbon of the original samples, after reduction experiment and control experiment for which samples are from 5 surface sediments in Prydz Bay, Antarctica. Then, the OC content was measured, and the OC-Fe content and fOC-Fe were calculated. The OC content measured with the rinse method was 34.82%±12.92%, 32.80%±15.11% and 26.15%±20.51% lower than with the fumigation method in the raw, control and after reduction samples, respectively. This implies notable dissolution of acid-soluble and water-soluble OC with rinse method, resulting in an ineffective of the control experiment. The OC-Fe content and the fOC-Fe values range obtained were significantly different between the two methods, indicating that the rinse method can partially dissolves OC bound with highly crystallized iron oxide or to low-activity iron silicate, thereby amplifying the fOC-Fe differences, and preventing accurate assessment of the OC-Fe contribution to OC in marine sediment. Therefore, fumigation method is the recommended method to remove inorganic carbon in the study of OC-Fe.

Key words:

marine sediments, organic carbon, reactive iron, rinse method, fumigation method