毛细管电泳定量检测环境水样中无机阴离子

Determination of inorganic anions in environmental water samples by Capillary Electrophoresis

详细讨论了胶束浓度、间接吸收背景物质的浓度及有机添加剂组成等对部分卤素及其含氧酸根的毛细管电泳分离影响;在优化的条件下,3.5min内高效、快速地完成了Cl-、Br-、ClO3-、BrO3-四种无机阴离子的分离分析,分离的理论塔板数在1.6×106～2.8×105/m之间,检出限在11.2～23.3mg/L之间,迁移时间的相对标准偏差小于1%,峰面积的相对标准偏差在5.2%～2.2%之间;并将方法用于环境水样的分析。

In this paper,the separation of Cl^-、 Br^-、 ClO_3^-、 BrO_3^- was studied with capillary electrophoresis. Parameters that affect the performance of the separation, such as the pH value and concentration of buffer, concentrations of an osmotic flow modifier and a chromate-based electrolyle, the type and content of mixed organic additives were investigated. Satisfactory separation of above four inorganic anions was obtained within 3.5 min in the buffer containing 1.5 mmol/L cetyltrimethyl ammonium bromide (CTAB), 0.5 mmol/L K_2CrO_4, 5 mmol/L Na_2B_4O_7, 3% glycerol and 10% ethyl alcohol (pH 8.0). The separation efficiencyies were between 1.6×10~6 and 2.8×10~5/m; the detection limits were less than 23.3 mg/L, the coefficients of variation for the retention times and the measurement of peak area were within 1.0% and 5.2%, respectively. This method was applied to the analysis of the environmental water samples.