毛细管电泳-间接紫外检测法测定酸性电解水中残留氯离子

Determination of residue chloride ions in acidic electrolyzed water by capillary zone electrophoresis with indirect ultraviolet detection

目的 建立酸性电解水中残留氯离子含量测定的毛细管电泳(CE)-间接紫外检测新方法。方法 CE-间接紫外检测法用未涂覆熔融石英毛细管(25μm×60.2 cm,有效长度为50 cm)为分离柱,以12 mmol/L硼砂、12 mmol/L硝酸钠和0.5 mmol/L十六烷基三甲基溴化铵为分离缓冲体系,检测波长214 nm;用离子色谱(IC)法验证新建方法的准确性。结果 CE-间接紫外检测法中氯离子的校正峰面积、IC法中氯离子的峰面积分别与一定范围内的质量浓度呈良好线性关系。CE-间接紫外检测法和IC法的检出限分别为2和0.1 mg/L;定量限分别为6和0.4 mg/L;CE-间接紫外检测法空白样品不同质量浓度加标回收率范围为98.0%~106.0%,相对标准偏差均<5%。方法的日内精密度为1.5%(n=7),日间精密度为2.5%(n=7)。结论 本研究建立的CE-间接紫外检测法简单、快速、准确,能够满足酸性电解水中氯离子残留量测定的检测需求,可作为IC测定残留氯离子的替代方法。

Objective To develop a new method for the determination of residue chloride ion content in acidic electrolyzed water.Methods For capillary electrophoresis(CE)with indirect ultraviolet detection method,uncoated fused silica capillary(25μm×60.2 cm,effective length of 50 cm)was used as separation column,with a separation buffer solution containing 12 mmol/L sodium borate,12 mmol/L sodium nitrate and 0.5 mmol/L hexadecyl trimethyl ammonium bromide at a detection wavelength of 214 nm;the accuracy of the CE method was verified by ion chromatography(IC).ResulstsThe calibration peak area of chloride ion in CE method and the peak area of chloride ion in IC method had a good linear relationships with the mass concentration within a certain range respectively.The detection limits of CE and IC methods were 2 mg/Land 0.1 mg/L,respectively;the quantitation limits were 6 mg/L and 0.4 mg/L,respectively;the recoveries of spiked blank samples with different mass concentrations ranged from 98.0%to 106.0%,and the relative standard deviations were all less than 5%.The intra-day precision was 1.5%(n=7),and the inter-day precision was 2.5%(n=7).Conclusion The CE method established in this study is simple,rapid and accurate,which meets the detection requirements for the determination of residue chloride ions in acidic electrolyzed water,and can be used as an alternative method for the determination of residual chloride ions by IC method.