测汞仪/高效液相色谱-电感耦合等离子体质谱联用法测定鱼松中总汞和甲基汞的含量

摘要

目的 测汞仪和高效液相色谱-电感耦合等离子体质谱法(high performance liquid chromatography-inductively coupled plasma mass spectromctry,HPLC-ICP-MS)测定鱼松中总汞及甲基汞的含量.方法 样品粉碎均匀后,无需前处理环节,直接通过测汞仪内置的模块对样品中的总汞进行一站式检测.以L-半胱氨酸-乙酸铵-甲醇-盐酸为提取液,高效液相色谱分离,ICP-MS为检测手段对样品中的甲基汞进行测定.结果 在优化的检测条件下,总汞的检出限为0.05 μg/kg,甲基汞的检出限为0.001 mg/kg;5种鱼松样品中总汞的加标回收率为80.2％～109.6％,甲基汞的回收率为85.0％～108.5％,样品中总汞和甲基汞的相对标准偏差均小于8.0％.样品中甲基汞在总汞中的含量约为49.3％～82.5％,是汞的主要存在形态.结论 该方法操作简便、提取效率高,可实现鱼松样品中总汞和甲基汞的快速测定.%Objective To determine the total mercury and methylmercury in fish-meat floss samples by mercury vapourmeter and high performance liquid chromatography-inductively coupled plasma mass spectrometry(HPLC-ICP-MS).Methods The total mercury in samples was directly detected by the inner modules of mercury vapourmeter without any pretreatment after the samples were crushed and homogenized.The determination of methylmercury was carried out using L-Cysteine-ammonium acetate-methanol-hydrochloric acid as the extraction agent,the samples were separated by high performance liquid chromatography,and the methylmercury was detected by ICP-MS.Results The method detection limits of total mercury and methylmercury were 0.05 μg/kg and 0.001 mg/kg,the recoveries of total mercury and methylmercury in 5 fish-meat floss samples were 80.2％～109.6％ and 85.0％～108.5％,respectively.The relative standard deviations (RSDs) of total mercury and methylmercury in samples were less than 8％.The content of methylmercury in total mercury in samples was 49.3％～82.5％,and mcthylmcrcury was thc main form of mcrcury.Conclusion This method has the advantages of simple operation and high extraction efficicncy,which can rcalize the rapid determination of total mercury and methylmercury in fish-meat floss samples.