毛细管电泳-多壁碳纳米管/聚吡咯/磷钼酸修饰电极电化学检测饮用水中的溴酸根

Determination of Bromate in Drinking Water by Capillary Electrophoresis-Electrochemical Detection with MWCNTs/PPy/PMo_(12) Modified Electrode

用电化学聚合法制备多壁碳纳米管/聚吡咯/磷钼酸修饰电极,利用循环伏安法研究溴酸根在此修饰电极上的电化学行为。考察了实验参数对分离检测体系的影响,并在优化条件下,采用毛细管电泳-安培检测法对溴酸根进行检测。结果表明:溴酸根离子在1.0×10-6～5.0×10-3 mol/L范围内和峰面积呈良好的线性关系,检出限(S/N=3)为4.0×10-7 mol/L,峰面积和迁移时间的相对标准偏差分别为1.9%和1.4%(5×10-3mol/L溴酸根,n=11)。将该体系应用于加标饮用水样的测定,回收率为97%～103%。

A MWCNTs/PPy/PMo12 modified pencil graphite electrode（PGE） was developed.The capillary electrophoresis with amperometric detection（CE-AD） method was employed for the determination of bromate（BrO-3）without the interference of chlorate（ClO-3）and iodate（IO-3）in drinking water with the MWCNTs/PPy/PMo12/PGE electrode.The effects of several factors on CE-AD were investigated.Under the optimum conditions,bromate could be well separated in the capillary at the working potential of-0.24 V,separation voltage of-15 kV,injection time for 6 s at-15 kV in a phosphate running buffer（KH2PO4-H3PO4,50 mmol/L,pH=2.4）.The peak area was linear with the concentration of bromate from 1.0×10-6 mol/L to 5.0×10-3mol/L with a detection limit（S/N=3） of 4.0×10-7mol/L.The RSDs（n=11） of peak area and retention time for the determination of bromate were 1.9% and 1.4%（n=11）,respectively.The proposed method was successfully used to analyze bromate in water samples with recoveries of 97%～103%.