Determination of Pb2+ in water using poly(pyrrole thiourea) electrode coupled with an electrochemical flow analysis device

Abstract

AbstractLead (Pb2+), due to its non‐biodegradable property and biological accumulation, would have adverse effects on human body. In this study, a poly(pyrrole thiourea) modified electrode was developed using the electropolymerization of pyrrole and thiourea. Compared with drop‐casting method, the immobilization of the modified material with fixator and the modification efficiency of an electrode was improved. The poly(pyrrole thiourea) electrode was applied for the in‐situ determination of Pb2+ in water coupled with an electrochemical flow analysis device. Several experimental parameters were optimized and the interference of the common co‐existing ions were evaluated. The precision and the repeatability of the electrode‐modified method were also examined. The relative standard deviation of response currents to 20 μg L−1 Pb2+ was found to be 4.6 % (n=90) and the recoveries varied from 91.6 % to 110.2 % in the determination of tap water and lake water samples obtained from laboratories and the university campuses. The limit of detection (3σ/Slope) of 0.03 μg L−1 for Pb2+ within the range of 0.1–100 μg L−1. Finally, the continuous monitoring of Pb2+ in water was successfully done by this developed method.