Voltammetric Determination of Pb, Cu and Hg in Biodiesel Using Gold Screen‐printed Electrode: Comparison of Batch‐injection Analysis with Conventional Electrochemical Systems

Abstract

AbstractThis article compares the use of batch‐injection analysis (BIA) with a conventional batch system for the anodic stripping voltammetric (ASV) determination of Pb, Cu and Hg in biodiesel using screen‐printed gold electrode (SPGE). The optimized BIA conditions were 200 µL of injection volume of the digested samples at 5 µL s−1 directly on the working electrode of the SPGE immersed in 0.1 mol L−1 HCl solution. Therefore, BIA‐ASV presented the advantages of low sample consumption, which extended the SPGE lifetime to a whole working day of analyses, and potential for on‐site analysis using battery‐powered micropipettes and potentiostats. Although presenting lower sensitivity than conventional systems, the BIA‐ASV presented detection limit values of 1.0, 0.5 and 0.7 µg L−1, respectively for Pb, Cu and Hg, a linear range between 20 and 280 µg L−1, and adequate recovery values (90–110 %) for spiked biodiesel samples.