电化学传感法测定水中亚硝酸盐

借助于简单可控的在线电聚合方法,溴酚蓝被修饰到玻碳电极表面,制备了聚溴酚蓝修饰玻碳电极。实验表明,聚溴酚蓝薄膜对于亚硝酸盐的电化学氧化具有很好的催化作用。经实验优化,聚溴酚蓝膜的最佳厚度为聚合20圈,最佳的检测底液为pH=4.0的0.01 mol/L磷酸盐缓冲溶液。亚硝酸盐在传感器上的电化学氧化是一个双电子双质子参与的过程。在最佳检测条件下,亚硝酸盐的氧化峰电流与其浓度在0.02~109.1μmol/L范围内有良好的线性关系,检测限低至5 nmol/L(S/N=3),所制备的亚硝酸盐传感器线性范围宽、检出限低、稳定性和重现性好、抗干扰能力强,将传感器应用于东湖水样中亚硝酸盐含量的测定,结果令人满意。

Detecting Nitrite in Water with Electrochemical Sensing Method

Poly (bromophenol blue) film modified glassy carbon electrode was fabricated through a simple and controllable in situ electro-polymerizing method, and experiment results show that the poly (bromophenol blue) film has good catalytic ability to the electrochemical oxidation of nitrite. The optimal thick of poly (bromophenol blue) film was electro-polymerized for 20 cycles and the optimal detection electrolyte was 0.01 mol/L pH=4.0 phosphat buffer solution. Moreover, the electrochemical oxidation of nitrite on the sensor was a two-electron and two-proton participation process. The sensor has wide linear range, low detection limit, good stability and anti-interference ability et al. At last, this sensor was successfully applied in detecting nitrite from water of the East lake.