金属钼离子选择电极对水中磷酸根离子的测定方法  

Determination method of phosphate ion based on molybdenum ion selective electrode

作　　者：刘亚楠 杨慧中 崔宝同[2] LIU Yanan;YANG Huizhong;CUI Baotong(Key Laboratory of Advanced Control of Light Industry Process,Ministry of Education,Jiangnan University,Wuxi 214122,China;School of Internet of Things Engineering,Jiangnan University,Wuxi 214122,China)

机构地区：[1]江南大学,轻工过程先进控制教育部重点实验室,无锡214122 [2]江南大学物联网工程学院,无锡214122

出　　处：《环境工程学报》2020年第12期3541-3548,共8页Chinese Journal of Environmental Engineering

基　　金：国家自然科学基金资助项目(61773181);中央高校基本科研业务费专项资金(JUSRP51733B)。

摘　　要：基于金属钼的离子选择电极在磷酸根离子检测过程中,被测溶液的pH、温度变化是影响电极检测精度的重要因素,研究了钼电极的输出电位与被测溶液磷酸根离子浓度、pH和温度之间的关系,探讨各干扰因素对检测结果的影响。利用磷酸根在不同pH条件下的分布系数,根据能斯特方程,采用最小二乘回归分析的方法,建立了钼电极的输出电位与磷酸根离子浓度、pH、温度之间的数学模型。结果表明:该测量模型在10^−6~10^−1 mol·L^−1的Na2HPO4溶液中检测误差在6.33%以内;与离子色谱法检测进行对比,最大相对误差为5.50%。利用电极法结合多元线性回归模型进行溶液磷酸根离子含量的检测,可补偿被测溶液pH和温度变化对电极测量的影响,有效提高磷酸根离子选择电极的测量精度。In the process of phosphate ion detection based on metal molybdenum ion-selective electrode,the changes of pH and temperature of the measured solution are important factors affecting the electrode detection accuracy.The relationships between the output potential of the molybdenum electrode and the phosphate ion concentration,pH value and temperature of the tested solution were studied,and the influence of various interference factors on the detection results were discussed.Based on the distribution coefficient of phosphate at different pHs and Nernst equation,a mathematical model was established with the least squares regression analysis method between the output potential of the molybdenum electrode and the phosphate ion concentration,pH and temperature.The experimental results show that the relative error of the measurement model in Na2HPO4 solution of 10^−6~10^−1 mol·L^−1 was within 6.33%.And compared with the ion chromatography detection,the maximum relative error was 5.50%.Therefore,the electrode method combined with the multiple linear regression model for the detection of the content of phosphate ion in the environmental water can compensate the influence of the pH and temperature changes of the measured solution on the electrode measurement.This method can effectively improve the measurement accuracy of phosphate ion selective electrode.

关 键 词：离子选择电极 磷酸根 补偿模型 分布系数 温度 

分 类 号：X832[环境科学与工程—环境工程]