高效液相色谱-电感耦合等离子体质谱联用测定动物源性中药材中无机汞和甲基汞

Determination of methylmercury and mercury in animal Chinese herb by HPLC-ICP-MS

目的：建立动物源性中药材中汞和甲基汞的检测方法。方法：从0.5g中药材中萃取汞（Hg）化合物,通过向0.2g冻干的样品材料加入50mL水1%w/v的L-半胱氨酸·HCl·H2O,在玻璃小瓶中60℃下加热120min。50μL汞化合物提取物经过滤后注入反相液相色谱仪,经C-18柱、流动相含水0.1%w/v L-半胱氨酸·HCl·H2O＋0.1%w/v的L-半胱氨酸,室温下分离,并通过电感耦合等离子体-质谱法在质荷比202检测。总汞为甲基汞和无机汞提取物之和。结果：中药材样品中甲基汞在0.055~2.78mg·kg-1范围,无机汞在0.014~0.137mg·k-1范围内两者精密度即相对标准偏差（RSD）分别为≤5%和≤9%。目标化合物加标回收率甲基汞为78.0%~98.8%,无机汞为87.3~94.5%。参考样品中的甲基汞和总汞与标准值一致。甲基汞和无机汞在中药材中的定量下限分别为0.007mg·kg-1和0.005mg·kg-1。结论：分析物的稳定性评价证实L-半胱氨酸既能稳定又能对甲基汞脱烷基化,这些都取决于半胱氨酸的浓度和稳定时间。聚丙烯会对甲基汞稳定性产生不利影响。

A method was developed for determination of methylmercury and mercury in the animal Chinese herb.The determination result showed that L-cysteine could make methylmercury stable and to de-alkylated by controling the time and concentration.Polypropylene could affect methylmercury stability.