摘要
设计了一套基于离子选择性电极与单片机技术的土壤重金属含量检测系统,并基于能斯特(Nernst)方程与最小二乘法研究了离子选择性电极响应电位与目标离子浓度的线性回归模型,建立两者之间的函数关系。采用离子选择性电极作为信号采集器,通过单片机系统和串行模数转换模块实现了较高精度、低成本的数据采集,并基于LabVIEW 8.2软件开发上位机软件实现了数据的显示、保存和打印。通过相关实验,得到铜离子选择电极响应电位E与离子浓度C的线性回归方程为E=267.047+29.494lg C_(Cu^(2+)),线性相关系数R^2=0.996 2。运用标准浓度硝酸铜溶液对回归模型进行了验证,线性回归模型的计算值与实际值间的相对误差在2.0%~7.2%之间。实验结果表明,回归模型的预测效果基本上可以满足一般精度要求的检测,检测系统可以用于土壤痕量重金属的初步检测分析。
A soil heavy metals content detection system based on MCU and ion-selective electrodes was designed, and the linear regression model was studied and the function relation between the ion selective electrode response potential and target ion concentration was established. Ion-selective electrodes were used to be signal acquisition. MCU and A/D chip were used to compose data acquisition system. A PC software has being developed which was used for data processing based on LabVIEW8.2. According to the experiments, a math model with response potential E as independent variable and ion concentrations C as dependent variable is established as E=267.047＋29.494 lg C_（Cu^（2＋）） with the linear correlation coefficient R^2 as 0.996 2. The model was verified through relevant experiments,and the relative error between 2.0% and 7.2% was obtained.The experimental results showed that the prediction effect of the regression model basically met the requirement of accuracy in general, indicating the system can be used for preliminary inspection of trace heavy metals in soil analysis.
出处
《环境科学与技术》
CAS
CSCD
北大核心
2015年第11期179-183,共5页
Environmental Science & Technology
基金
海南省自然科学基金资助项目(614223)
