应用化学 ›› 2022, Vol. 39 ›› Issue (9): 1360-1370.DOI: 10.19894/j.issn.1000-0518.210300

• 研究论文 • 上一篇    下一篇

微波辅助提取-固相膜萃取测定水体沉积物中的甲基汞

赵欣1, 刘贺1, 武中波1, 王鹤1, 汪子明2()   

  1. 1.吉林省生态环境监测中心,长春 130011
    2.吉林大学化学学院,长春 130012
  • 收稿日期:2021-06-19 接受日期:2021-12-11 出版日期:2022-09-01 发布日期:2022-09-08
  • 通讯作者: 汪子明

Determination of Methyl‑mercury by Microwave Assisted Extraction‑Solid Phase Membrane Extraction in Water Sediments

Xin ZHAO1, He LIU1, Zhong-Bo WU1, He WANG1, Zi-Ming WANG2()   

  1. 1.Ecology and Environmental Monitoring Center of Jilin Province,Changchun 130011,China
    2.College of Chemistry,Jilin University,Changchun 130012,China
  • Received:2021-06-19 Accepted:2021-12-11 Published:2022-09-01 Online:2022-09-08
  • Contact: Zi-Ming WANG
  • About author:wangziming@jlu.edu.cn

摘要:

利用微波辅助提取-固相膜萃取前处理技术分离富集水体沉积物中的甲基汞,固相膜萃取的前处理方法能够集富集和净化为一体,有效地去除基质的影响。方法的关键在于样品的萃取过程,萃取过程中既要保证样品中甲基汞的原来形态不被破坏和转化,又要保证其从样品中被充分萃取以达到稳定可靠的回收效果。通过微波辅助提取技术将水体沉积物中的甲基汞提取到溶液后,提取液通过0.01%的二乙基二硫代氨基甲酸钠改性后的C18固相萃取膜,选择性地将提取液中的甲基汞分离富集的同时净化。洗脱液再经过原子荧光光谱仪进行测定。实验条件考察了流动相、微波提取条件以及固相膜萃取条件对甲基汞的影响。在最优的实验条件下,对甲基汞的稳定性进行了研究,实验结果表明在4 ℃以及-15 ℃条件下贮存,甲基汞降解不显著。同时对沉积物实际样品和加标样品进行了分析,所得结果沉积物中甲基汞检出限为0.20 μg/kg,沉积物实际样品的加标回收率和相对标准偏差分别在71.3%~87.6%和2.00%~6.36%之间,实验结果令人满意。该方法萃取速度快、消耗溶剂少、萃取效率高,可以同时处理多个样品,节约能耗,绿色环保,符合现代监测分析的发展趋势,适用于分析测定水体沉积物中的甲基汞。

关键词: 微波辅助提取, 固相膜萃取, 水体沉积物, 甲基汞

Abstract:

A novel and simple method of microwave assisted extraction combined with solid phase membrane extraction enrichment and purification with high performance liquid chromatography-atomic fluorescence spectrometer (LC-AFS) for determination of methyl-mercury in water sediments is developed. The key of this method is the extraction process of the sample, in the extraction process, it is necessary to ensure that the original form of methyl mercury in the sample is not damaged and transformed, and it is fully extracted from the sample to achieve stable and reliable recovery. The methyl-mercury in water sediment is extracted to the solution by microwave-assisted extraction technology. The C18 solid phase extraction membrane is modified by 0.01% diethyldithiocarbamate, and the methyl-mercury is enriched and purified at the same time. The eluent is determined by LC-AFS. Some experimental conditions such as the effects of mobile phase, microwave extraction conditions and solid phase membrane extraction conditions on methyl-mercury are investigated. Under the optimal experimental conditions, the actual sediment samples and the spiked samples are analyzed, and the results obtained show that the detection limit of methyl-mercury is 0.20 μg/kg in the sediment, and the relative standard deviation is 2.0%~6.36%. The spiked recovery is 71.3%~87.6%, and the experimental results are satisfactory. This method has the advantages of fast extraction speed, less solvent consumption and high extraction efficiency, which can simultaneously process multiple samples and save energy consumption. It is the development trend of modern monitoring and analysis and is suitable for the analysis and determination of methyl-mercury in water sediments.

Key words: Microwave-assisted extraction, Solid phase membrane extraction, Water sediments, Methyl mercury

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