基于NPsNi-Nafion-GO修饰平面电极和3D薄层流通池的水体化学耗氧量快速检测系统

Establishment of a rapid detection system for chemical oxygen demand based on NPsNi-Nafion-GO modified planar electrode and 3D thin-layer flow cell

目的建立流动状态下检测水体化学耗氧量(COD)的电化学分析方法。方法以NPsNi-Nafion-GO修饰的平面电极与3D打印薄层流通池相匹配,用微型蠕动泵驱动样品流经电极表面,用计时电流法进行测定。结果所建立的动态测定装置对COD响应时间为1.5min,测定范围1~400mg/L,线性方程i(μA)=1.737 5 c (mg/L)-0.896 6,线性相关系数(r)为0.996 1,检出限0.2mg/L,样品需求量2mL,相对偏差(RSD)为2.5%~3.9%(n=9),与标准方法(GB/T 5750.7-2006)测定结果进行比较,相对误差在3.0%~6.4%。结论该检测系统与标准检测方法具有良好相关性,灵敏度高,操作简单,避免二次污染,便携优势较突出。

Objective To establish a electrochemical analysis system for rapid determination of chemical oxygen demand (COD)in flow state.Methods A planar electrode modified with NPsNi-Nafion-GO was matched with a 3Dprinted thin-layer cell.The sample was driven smoothly through the electrode surface by a micro peristaltic pump and then measured by chronoamperometry. Results The response time of established mobile detection system was 1.5min,the linear range of COD was 1- 400mg/L.The linear equation was i(μA)=1.737 5 c (mg/L)–0.896 6(r=0.996 1)and the detection limit was 0.2mg/L. The sample demand was 2mL.The relative deviation(RSD)was 2.5%-3.9%(n=9).Compared with the results by the standard method (GB/T 5750.7-2006),the relative errors of results by established method were from 3.0% to 6.4%. Conclusion The established system have good correlation with standard detection method,with high sensitivity,simple operation, avoiding secondary pollution,demonstrating prominent advantage of portability.