高效液相色谱-电感耦合等离子体质谱法测定汞的3种形态

Study on Three Mercury Speciations with High Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry

利用HPLC-ICP-MS联用技术对Hg的3种不同形态(甲基汞、乙基汞、Hg2+)进行分析,通过条件优化,确定了最佳分离条件:流动相为超纯水并含有5%甲醇、0.06 mol/L乙酰胺和0.1% 2-巯基乙醇、进样量1000 μL、流速0.4 mL/min 、pH=6.8,最佳检测条件是:RF功率1550 W、积分时间0.3 s、采样深度:4.5 mm、载气流速0.75 L/min、辅助气流速0.40 L/min.在此条件下,3种形态汞的检出限达到0.1 ng/L,检出限降低两个数量级;同时对模拟海水样品中3种形态微量的汞进行测定,加标回收率在90%～110%之间.说明该方法可应用于微含量环境样品的分析.

This study mainly describs the analysis of three different mercury speciations （MeHg, EtHg and Hg^2＋ ） with high performance liquid chromatography-inductively coupled plasma-mass spectrometry, the detection limit can achieve 0.1 ng/L and is decreased by 2 orders under the optimum conditions including that the mobile phase was water with 5% methanol 0. 1% 2-mercaptoethanol and 0.06 mol/L ammonium acetate,sample amount was 1000μL and the flow rate was 0.4 mL/min, the optimum checking conditions included RF power was 1550 W, integral time was 0.3 s, sampling depth was 4.5 mm, velocity of carrier gas was 0.75 L/min, and velocity of auxiliary gas was 0.40 L/min. In addition, trace mercury speciations in the simulating seawater were analysed, the results show this method can be applied to the trace analysis of environmental samples.