Study of analytical parameters of a differential pulse voltammetric method using chemically modified electrodes for lead analysis in water

Abstract

The development of a new voltammetric method for the determination of Pb2+ ions in water samples using glassy carbon electrodes modified with 2,6-bis((E)-2-(thiophen-2-yl)vinyl)-4-(4,6,8-trimethylazulen-1- yl)pyrylium perchlorate is here presented. The analytical parameters for differential pulse voltammetry (DPV) were established and the method was applied for Pb2+ ions determination in acetate buffer solution at pH 5.5. For the developed DPV method the linearity of calibration curve was set up between 20.71µg L-1 - 103.6µg L-1 with a good correlation coefficient R2=0.9988, the intermediate precision was calculated for three lead concentrations:20, 60,100µg L-1.The obtained detection and quantification limits were 3.1µg L-1, respectively 10.4µg L-1. An uncertainty budget was developed and the value of expanded uncertainty was assessed. The optimized method was used to analyze Pb2+ ions from of water samples and good correlation with standard method was obtained.