基于低流速雾化器和可拆卸接口的毛细管电泳-电感耦合等离子体质谱联用技术应用于汞的形态分析

报道了基于低流速雾化器(MicroMist)和随意拆卸接口的毛细管电泳(CE)-电感耦合等离子体质谱联用技术，并将其应用于汞的形态分析。这种可随意拆卸接口避免了毛细管冲洗过程中对检测器的污染。无机汞和甲基汞在下列电泳条件下得到了基线分离： CE分离毛细管为45 cm×75 μm石英熔硅毛细管，电解质溶液为30 mmol·L-1 H₃BO₃+10% CH₃OH(pH 8.7)，分离电压为22.5 kV。汞形态的迁移时间和峰面积的精密度分别是(RSD, n=5)分别为3.5%～3.8%和2.3%～5.1%。甲基汞和无机汞的检出限(3σ)分别是47和48 μg·L-1。

Speciation Analysis of Mercury by Capillary Electrophoresis On-Line Coupled with Inductively Coupled Plasma Mass Spectrometry Based on a Micro Mist Nebulizer and a Removable Interface

A method for mercury speciation analysis was developed by CE-ICP-MS with a Micro Mist nebulizer and a removable interface. Contamination of ICP-MS detector by the rising solution was avoided with the use of a removable interface during capillary rinsing. Baseline separation of methylmercury (MeHg) and inorganic mercury (Hg2+) was obtained by CE in a 45 cm x 75 microm i.d. fused-silica capillary at 22.5 kV, while a mixture of 30 mmol(-1) H3BO3 + 10% CH3OH (pH 8.7) acted as running electrolyte. The precisions (RSD, n=5) of migration time and peak area for the mercury species were in the ranges of 3.5%-3.8% and 2.3%-5.1%, respectively. The limits of detection (3sigma) of MeHg and Hg2+ were 47 and 48 microg x L(-1), respectively.