Robust microwave-assisted extraction protocol for determination of total mercury and methylmercury in fish tissues.
Robust microwave-assisted extraction protocol for determination of total mercury and methylmercury in fish tissues.
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DOI：
10.1016/j.aca.2008.10.044
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发表时间：
2009-01
影响因子：
6.2
通讯作者：
L. H. Reyes;G. M. M. Rahman-G.-M.-M.-Rahman-37969454;H. Kingston
中科院分区：
文献类型：
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作者：
L. H. Reyes;G. M. M. Rahman-G.-M.-M.-Rahman-37969454;H. Kingston
建立了一种快速高效的封闭式微波辅助萃取（MAE）方法，并优化了该方法对鱼组织中总汞（Hg）、无机汞（Hg 2+）和甲基汞（CH 3 Hg+）的萃取条件。生物样品中总汞和汞形态的定量萃取是通过在60°C下使用5 molL −1HCl和0.25molL− 1 NaCl在10分钟内实现的。采用电感耦合等离子体质谱法（ICP-MS）测定总汞含量。采用液相色谱-电感耦合等离子体质谱联用（LC-ICP-MS）测定汞的形态。使用生物认证参比物质ERM-CE 464、DOLT-3和NIST SRM-1946对该方法进行了验证。在95%的置信水平下，分析结果与总汞和CH 3 Hg+的认证参考值吻合良好。此外，使用物种化同位素稀释质谱法（SIDMS，如EPA方法6800中所述）进行准确度验证。SIDMS还用于研究和校正样品制备步骤期间和/或之后的不需要的物质转化反应。对于所研究的参比物质，在提取和测定过程中未观察到汞物种之间的统计学显著性转化。所提出的方法被成功地应用于鱼组织与SIDMS结果和外部校准（EC）结果之间的良好协议。由于基质组成的差异，鱼类组织中的种间转化略高于经认证的参考物质。根据鱼组织的类型，高达10.24%的Hg 2+被甲基化，高达1.75%的CH 3 Hg+被去甲基化为Hg 2+。
A rapid and efficient closed vessel microwave-assisted extraction (MAE) method based on acidic leaching was developed and optimized for the extraction of total mercury (Hg), inorganic mercury (Hg2+) and methylmercury (CH3Hg+) from fish tissues. The quantitative extraction of total Hg and mercury species from biological samples was achieved by using 5molL−1HCl and 0.25molL−1NaCl during 10min at 60°C. Total Hg content was determined using inductively coupled plasma mass spectrometry (ICP–MS). Mercury species were measured by liquid chromatography hyphenated with inductively coupled plasma mass spectrometry (LC–ICP–MS). The method was validated using biological certified reference materials ERM-CE464, DOLT-3, and NIST SRM-1946. The analytical results were in good agreement with the certified reference values of total Hg and CH3Hg+at a 95% confidence level. Further, accuracy validation using speciated isotope-dilution mass spectrometry (SIDMS, as described in the EPA Method 6800) was carried out. SIDMS was also applied to study and correct for unwanted species transformation reactions during and/or after sample preparation steps. For the studied reference materials, no statistically significant transformation between mercury species was observed during the extraction and determination procedures. The proposed method was successfully applied to fish tissues with good agreement between SIDMS results and external calibration (EC) results. Interspecies transformations in fish tissues were slightly higher than certified reference materials due to differences in matrix composition. Depending on the type of fish tissue, up to 10.24% of Hg2+was methylated and up to 1.75% of CH3Hg+was demethylated to Hg2+.