黑火药余烬中无机阴离子的毛细管电泳方法研究

Development of Capillary Electrophoretic Method for Determination of the Inorganic Anions in the Ash of Black Powder

发展了一种用于黑火药余烬中无机阴离子测定的毛细管电泳分析方法。对缓冲溶液的组成及pH值、电渗流改性剂的浓度以及分离电压等条件进行了研究。选定条件 :分离电压为 - 2 0kV ,缓冲溶液为 5 0mmol/L的Na2 CrO4(pH 8 2 0 ) ,电渗流改性剂为 0 5mmol/L的溴化十六烷基三甲基铵 (CTAB) ,检测波长为 2 5 4nm。在上述条件下 ,5种阴离子在 4min内可完全分离。各组分迁移时间和峰面积的相对标准偏差 (RSD)分别为 0 17%～1 4 0 %和 3 9%～ 5 0 % ,最低检测限为 5 0 μmol/L～ 10 0 μmol/L。用该法对某黑火药余烬中的无机阴离子进行分析 ,发现其中含有Cl-和NO2 -,测定其浓度的相对标准偏差分别为 6 0 %和 3 9% 。

A capillary electrophoretic method for determining the inorganic anions in the ash of black powder has been developed. The components and pH of the buffer solution, the concentration of osmotic flow modifier and the separation voltage were investigated. The optimized parameters were 5 0 mmol/L sodium chromate buffer solution (pH 8 20) containing 0 5 mmol/L cetyltrimethylammonium bromide (CTAB) as osmotic flow modifier, a separation voltage of -20 kV and a detection wavelength of 254 nm. Under the specified conditions five anions were completely separated in four minutes, and the repeatabilities (RSD) of migration time and peak area were in the range of 0 17%-1 4% and 3 9%-5 0%, respectively. The detection limits were in the range of 5 0 μmol/L to 10 0 μmol/L. To show the usefulness, the method was applied to analyze the ash of a black powder and the results showed that the relative standard deviations of the determination for Cl - and NO 2 - were 6 0% and 3 9%, respectively.