卫生研究

目的考察并优化同位镀锑膜修饰玻碳电极同时测定Pb2+、Cd2+的方法。方法采用十六烷基三甲基溴化铵(CTAB)作为增敏剂,以锑膜修饰玻碳电极作为工作电极差分脉冲溶出伏安法测定尿中痕量Pb2+、Cd2+。结果 Pb2+、Cd2+在锑膜电极上可得到灵敏的溶出峰,溶出电位分别为-0.48 V和-0.73 V。当富集时间为180 s时,Pb2+、Cd2+的线性范围为0~100μg/L(r≥0.991),检出限分别为0.47μg/L和0.78μg/L,Pb2+、Cd2+的加标回收率分别为92.0%~104.3%和94.0%~102.6%,相对标准偏差(RSD)分别为4.1%⁵.0%和2.8%⁶.1%。利用该方法测定了尿样中Pb的含量,结果令人满意。结论该方法灵敏度高,精密度、准确性好,锑膜修饰玻碳电极可作为一种新的环保膜电极代替汞膜电极用于尿样中Pb含量的检测。

Objective To investigate and optimize the experiment conditions of determining lead and cadmium simultaneously with antimony film-plated glassy carbon electrode. Methods CTAB was used as sensitizer,and antimony film-plated glassy carbon electrode was prepared by in-situ plating for the determination of trace lead and cadmium by differential pulse stripping voltammetry. Results Under optimized conditions,well defined peaks of lead and cadmium were obtained at the potential of-0. 48 V and- 0. 73 V respectively. Following a 180 s preconcentration,the stripping peak currents changed linearly with the concentration of lead and cadmium over the range from0 to 100 μg / L( r≥0. 991). The detection limits of lead and cadmium were 0. 47 μg / L and 0. 78 μg / L. The average recoveries were 92. 0%- 104. 3% and 94. 0%- 102. 6%respectively,with the relative standard deviations no more than 6. 1%. The method was applied to the determination of lead in urine,and the results were satisfactory. Conclusion The method has high sensitivity,good precision and accuracy. Antimony film electrodecould be used for another new environment-friendly membrance electrode for determination of lead in human urine samples instead of mercury film electrode.