超声波辅助溶剂萃取-电感耦合等离子体质谱法测定生物样品中的总汞和甲基汞

建立了超声波辅助溶剂萃取联用电感耦合等离子体质谱法(ICP-MS)测定生物样品中总汞(T-Hg)和甲基汞(MeHg)的分析方法。实验优化了萃取溶剂种类，溶剂浓度，各种辅助方法和超声波振荡时间等各种萃取条件。选择6 mol·L-1 HCl作为溶剂，超声2 h, 以有机溶剂萃取，再以水反萃，稀释后直接进行测量MeHg的含量。此方法可用于同时测定T-Hg和MeHg, 检出限为0.01 ng·mL-1,相对标准偏差为3.44％，线性范围为1～50 ng·mL-1,加标回收率为80%～97%。在此条件下测定了5种不同类型生物标准参考物质的T-Hg和MeHg，测定值与标准值吻合。该法综合了超声波辅助萃取和溶剂微萃取以及ICP-MS的优点，操作简便快速，灵敏度高，适合于各种生物样品中痕量MeHg快速萃取分离和分析。

Rapid Analysis of Methylmercury and Total Mercury in Biological Samples by Ultrasonic-Assisted Solvent Extraction Coupled with Inductively Coupled Plasma-Mass Spectrometry

The analytical method for the determination of total mercury and methylmercury in biological samples was studied using ultrasonic-assisted solvent extraction coupled with inductively coupled plasma-mass spectrometry. Various extraction conditions like solvent types and concentrations, different assisted methods, and ultrasonic radiation time were optimized. Samples were digested with 6 mol x L(-1) HCl, ultrasonicated for 2 hours, extracted by organic solvent, then back-extracted by water and directly measured after dilution. With the optimized method, the total mercury and methylmercury were simultaneously measured. The detection limit was 0. 01 ng x mL(-1) , the relative standard deviation (RSD) was 3. 44%, the linearity of calibration curve of mercury was in the concentrations of 0-50 ng x m(L-1), and the recovery of mercury given by standard addition method was 80%-97%. Mercury in five different biological standard reference materials was determined by the described method. The experimental results were in good agreement with the certified values. The proposed method takes the advantage of ultrasonic-assisted extraction, micro-solvent extraction, and ICP-MS, which is especially suitable for the analysis of mercury in different biological samples.