“方波脉冲伏安法检测水中铋”教学实验精密度的影响因素探究

Study on Influencing Factors of Precision of Teaching Experiment of“Square-wave Voltammetric Stripping Analysis of Bismuth Ion in Water”

我们对影响阳极溶出方波脉冲伏安法测量精密度的因素进行探究。结果显示:搅拌速度、抛光时间、超声时间、电化学清洗时间对结果精密度影响较大。根据正交实验,这四个因素对精密度的影响为:超声时间>搅拌速度>抛光时间>清洗时间。在选定的优化条件下,对浓度为10μmol/L,5μmol/L,1μmol/L铋标准样品分别平行测定5次的相对标准偏差为2.0%,2.5%,3.4%。优化后的实验方案操作更加精确、规范,更有利于学生掌握此项测试技术。

The factors affecting the accuracy of anodic stripping square wave voltammetry were investigated.The results showed that stirring speed,polishing time,ultrasonic time and electrochemical cleaning time had great influence on the precision of the results.According to the orthogonal experiment,the four factors were further sorted as follows:ultrasonic time>stirring speed>polishing time>electrochemical cleaning time.Under the optimized conditions,the relative standard deviations for 5 times of parallel determination of 10μmol/L,5μmol/L and 1μmol/L bismuth samples were 2.0%,2.5%and 3.4%,respectively.The optimized scheme was more accurate and standardized,which was more conducive to students to master this testing technology.