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

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

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.

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 （Hg^2＋ ） was obtained by CE in a 45 cm× 75μm i.d. fusedsilica 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 （3σ） of MeHg and Hg^2＋ were 47 and 48 μg·L^-1 , respectively.