鱼酥制品中甲基汞和乙基汞的检测研究

Detection and Analysis of Methyl Mercury and Ethyl Mercury in Dried Fish Floss

建立了同时测定鱼酥制品中甲基汞和乙基汞的液相色谱-电感耦合等离子体质谱的分析方法。样品以盐酸为提取液微波辅助萃取,采用5%甲醇+(0.10 mol/L乙酸铵-1 g/L L-半胱氨酸)为流动相,SB-C18柱(150 mm×4.6mm,5μm)进行分离,用电感耦合等离子体质谱仪进行检测,整个检测过程可在1 h内完成。试验优化了液相色谱流动相、微波萃取的萃取时间和温度等条件。在0~50μg/L范围内甲基汞和乙基汞的线性关系良好,线性相关系数大于0.999,甲基汞和乙基汞检出限(S/N=3)分别为0.001 8 mg/kg和0.003 6 mg/kg。样品在3个加标水平下的甲基汞和乙基汞的平均回收率分别为91.0%~98.8%和80.5%~87.6%,相对标准偏差(RSD)分别为2.6%~4.0%,3.3%~4.1%。该方法前处理简便,精密度高,准确性好,适用于鱼酥中甲基汞和乙基汞的测定。

A method of High performance liquid chromatography coupled with Inductively coupled plasma Mass spectrometry had been established for the separation and detection of Methyl Mercury and Ethyl Mercury in dried fish floss. The preliminary treatment of sample was carried out by microwave assistant extraction with hydrochloric acid as extractant. The sample was separated on the C18 chromatographic column （150 mm×4.6 mm, 5 μm） using 5% methanol -0.10 mol/L ammonium acetate-1 g/L L-cysteine as mobile phase. The testing optimization parameters were obtained by means of experiment. The liner ranges for Methyl Mercury and Ethyl Mercury were between 0-50 μg/L, and the limits were 0.001 8 mg/kg and 0.003 6 mg/kg. To fi.trther verify the viability of the method, recovery experiments were carried out. The recoveries of Methyl Mercury and Ethyl Mercury were 91.0%-98.8% and 80.5%-87.6%, and the relative standard deviations were 2.6%-4.0% and 3.3%-4.1%. In conclusion, the analysis method was proved to be simple, accurate, and stable by testing experiments.