液相色谱-电感耦合等离子体质谱法测定水产品中的4种形态汞

目的建立一种微波萃取-高效液相色谱分离-电感耦合等离子体质谱法(high performance liquid chromatography-inductively coupled plasma mass spectrometry,HPLC-ICP/MS)测定水产品中无机汞(inorganic me rcury,IMC)、甲基汞(methyl mercury,MMC)、乙基汞(ethyl mercury,EMC)和苯基汞(phenyl mercury,PMC)的方法。方法样品经25%四甲基氢氧化胺微波萃取后,用流动相定容,0.45μm微孔滤膜过滤后备用。样品经反相色谱柱分离,ICP/MS检测。结果4种形态的汞在质量浓度0.5~20 ng/mL的范围内呈线性关系,虾仁样品在0.01、0.02、0.2 mg/kg添加水平下的回收率为61.3%~113.7%;鳕鱼在0.01、0.02、0.5 mg/kg添加水平下回收率为60.8%~109.8%;金枪鱼在0.01、0.02、1.0 mg/kg添加水平下回收率为75.5%~115.9%,日内相对标准偏差小于8%,日间相对标准偏差小于10%;4种形态汞的检出限均为4μg/kg.结论该方法快速、准确、灵敏,适合用于水产品中4种汞形态分析检测。

Determination of 4 forms of mercury in aquatic products by liquid chromatography-inductively coupled plasma mass spectrometry

Objective To establish a method for the determination of inorganic mercury(IMC),methyl mercury(MMC),ethyl mercury(EMC),and phenyl mercury(PMC)in aquatic products by high performance liquid chromatography-inductively coupled plasma mass spectrometry(HPLC-ICP/MS).Methods After microwave extraction with 25%tetramethyl hydroxide,the samples were filtered by a 0.45μm microporous membrane using a mobile phase constant volume.The samples were separated by reversed-phase chromatographic column and detected by ICP/MS.Results The 4 forms of mercury showed linear relationships in the mass concentration range of 0.5-20 ng/mL.The recoveries of shrimp samples at the addition levels of 0.01,0.02,and 0.2 mg/kg were 61.3%-113.7%,the recoveries of cod at the addition levels of 0.01,0.02,and 0.5 mg/kg were 60.8%-109.8%;and the recoveries of tuna at the addition level of 0.01,0.02 and 1.0 mg/kg were 75.5%-115.9%.The intraday relative standard deviations were less than 8%,and the intraday relative standard deviations were less than 10%.The limits of detection of 4 forms of mercury were all 4μg/kg.Conclusion The method is rapid,accurate and sensitive,which is suitable for the analysis and detection of four kinds of mercury in aquatic products.