Wang Runyan, Chen Shanshan, He Qian, Xu Shengrui
College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100, China.
Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, China.
Anal Chem. 2024 Oct 29;96(43):17405-17412. doi: 10.1021/acs.analchem.4c04340. Epub 2024 Oct 20.
A novel method coupling solid-phase microextraction (SPME) to solid-phase dielectric barrier discharge (SPDBD) vapor generation was proposed and used for the sensitive detection of trace mercury (Hg) in seawater with atomic fluorescence spectrometry (AFS) in this work. The method proposed herein offers the unique advantages of integrating desorption and chemical vapor generation into one step, eliminating the use of elution reagents, and reducing the analysis time. SPME with multiwalled carbon nanotubes (MWCNTs) coated on the glass tube was used to extract Hg in seawater. The Hg was then desorbed and reduced to Hg vapor by SPDBD, which was detected by cold vapor AFS. The parameters affecting Hg extraction, desorption, and vapor generation were studied. The detection limit of Hg was 0.0003 μg L, and the relative standard deviation at a Hg concentration of 0.05 μg L was 4.4%. This method also has excellent antimatrix interference ability for Hg determination with recoveries between 91.8% and 101.1% in the presence of extremely high concentrations (two million times excess) of coexisting ions. The practicality of this method was also evaluated by analyzing two different certified reference materials of Hg in water and several seawater samples with good spike recoveries (94.0%-107.4%). Compared with solid-phase photothermo-induced vapor generation, this method has higher extraction efficiency and higher desorption efficiency without the assistance of heating as well as a lower detection limit of Hg, which is capable of performing trace Hg analysis in seawater.
本文提出了一种将固相微萃取（SPME）与固相介质阻挡放电（SPDBD）蒸气发生相结合的新方法，并用于通过原子荧光光谱法（AFS）灵敏检测海水中的痕量汞（Hg）。本文提出的方法具有将解吸和化学蒸气发生整合为一步的独特优势，无需使用洗脱试剂，并减少了分析时间。使用涂覆有多壁碳纳米管（MWCNT）的玻璃管进行SPME，以萃取海水中的Hg。然后通过SPDBD将Hg解吸并还原为Hg蒸气，通过冷蒸气AFS进行检测。研究了影响Hg萃取、解吸和蒸气发生的参数。Hg的检测限为0.0003 μg/L，Hg浓度为0.05 μg/L时的相对标准偏差为4.4%。该方法在Hg测定方面还具有出色的抗基体干扰能力，在存在极高浓度（超过两百万倍）共存离子的情况下，回收率在91.8%至101.1%之间。通过分析两种不同的水中Hg认证参考物质和几个海水样品，该方法的加标回收率良好（94.0% - 107.4%），从而评估了该方法的实用性。与固相光热诱导蒸气发生相比，该方法在无需加热辅助的情况下具有更高的萃取效率和更高的解吸效率，以及更低的Hg检测限，能够对海水中的痕量Hg进行分析。
