离子选择电极法测定氟离子方法的优化

Optimization of Ion-selective Electrode Method for Determination of Fluoride Ion

工业用水中氟离子的测定方法主要是离子色谱法和离子选择电极法。因离子选择电极法操作简单被广泛采用,在离子选择电极法测定过程中需要加入总离子强度调节缓冲剂,保持溶液的离子强度不变。总离子强度调节缓冲剂有多种配制方法,但最适用的配制方法是采用柠檬酸钠和硝酸钠的配制方法。因硝酸钠属于易爆化学试剂,管控严格,不易购买。采用氯化钠和柠檬酸钠作为总离子强度调节缓冲剂,不仅降低了分析成本,且分析结果准确,相对偏差0.36%,检出限为0.02mg/L,加标回收率为96.0%~103.6%,结果符合测定要求。

The main methods for determining fluoride ion in industrial water are ion chromatography and ion selective electrode method.The ion-selective electrode method is widely used because of its simple operation,but the total ionic strength adjustment buffer needs to be added during the determination of the ion-selective electrode method to keep the ionic strength of the solution unchanged.There are many preparation methods for total ionic strength adjustment buffer,but the most suitable preparation method is to use sodium citrate and sodium nitrate.Because sodium nitrate is an explosive chemical reagent,it is strictly controlled and difficult to buy.The use of sodium chloride and sodium citrate as the total ionic strength adjustment buffer not only reduces the analysis cost,but also the analysis results are accurate,with a relative deviation of 0.36%,a detection limit of 0.02mg/L,and a standard recovery rate of 96.0%-103.6%,the results meet the determination requirements.