甲苯萃取-原子荧光光谱法检测鱼肉中甲基汞

目的建立甲苯萃取-原子荧光光谱检测鱼肉中甲基汞的方法。方法样品经48%氢溴酸水解、甲苯萃取、0.05 mol/L硫代硫酸钠反萃取后,应用AFS-9230原子荧光光谱法进行测定,同时经此前处理后的样品采用DMA-80直接测汞仪进行测定,与原子荧光光谱法的结果进行对比。结果原子荧光光谱法以及直接测汞仪直接测定的结果与标准物质定值吻合,确证该方法的可靠性,适用于鱼、贝等水产品中甲基汞的测定。采用该方法对鱼肉中总汞与甲基汞成分分析标准物质GBW10029以及英国食品分析水平评估计划(food analysis performance assessment scheme,FAPAS)的罐装鱼肉样品(样品编号07189)进行了检测,检测结果与参考物定值吻合,回收率分别为96.1%,97.5%。结论该方法操作简单,灵敏度高,重现性好,适用于鱼肉中甲基汞含量的定量检测。

Determination of methyl mercury in fish by toluene extraction and atomic fluorescence spectrometry

Objective To establish a method for the determination of methyl mercury in fish by toluene extraction and atomic fluorescence spectrometry (AFS). Methods Samples were digested by HBr(48%, v/v) for 30 min, and methyl mercury was extracted by methylbenzene. The extract was back-extracted into aqueous solution by Na2S2O3. The aqueous solution was ready for the analysis by atomic fluorescence spectrometry (AFS). And the present method was used to determine the concentration of methyl mercury in reference materials. Results The result was in accordance with the assigned value. Recoveries were 96.1% and 97.5% respectively. Conclusion The method is effective to determine methyl mercury in fish for its high sensitivity and reproducibility.