毛细管区带电泳技术快速分离检测爆炸残留物中的无机离子

Determination of inorganic ions in explosive residues by capillary zone electrophoresis

利用间接紫外毛细管区带电泳方法完成了对爆炸残留物中7种无机离子(K+,NH4+,NO2-,NO3-,SO42-,ClO3-,ClO4-)的分离检测。阳离子测定采用的缓冲体系为10mmol/L吡啶(pH4.5)-3mmol/L冠醚,K+和NH4+在2.6min内达到基线分离,检出限分别为0.25mg/L和0.10mg/L(S/N=3)。阴离子测定采用的缓冲体系为40mmol/L硼酸-1.8mmol/L重铬酸钾-2mmol/L硼酸钠(pH8.6),氢氧化四甲铵为电渗流改性剂,5种阴离子在4.6min内达到基线分离,检出限为0.10～1.85mg/L。该方法已成功地应用于实际爆炸物样品种类的判定分析,取得了很好的结果。

Five anions（chlorate,perchlorate,nitrate,nitrite,and sulfate）and two cations（ammonium and potassium）in explosive residues have been separated and determined by capillary zone electrophoresis（CZE）with indirect ultraviolet detection.The electrolyte buffer for the cation separation was 10 mmol/L pyridine（pH 4.5）-3 mmol/L 18-crown-6-ether.Ammonium and potassium ions were baseline separated in less than 2.6 min with the detection limits of 0.10 mg/L and 0.25 mg/L（S/N=3）,respectively.The electrolyte buffer for the anion separation consisted of 40 mmol/L boric acid-1.8 mmol/L potassium dichromate-2 mmol/L sodium tetraborate（pH 8.6）,and tetramethyl ammonium hydroxide（TMAOH）was used as electro-osmotic flow modifier.All five anions were well separated in less than 4.6 min with the detection limit range of 0.10-1.85 mg/L（S/N=3）.The method was successfully used in real sample investigations to confirm the type of explosives.