Fabrication and characterization of Prussian blue screen-printed working electrode and their application for free chlorine monitoring in swimming pool water

摘要

A Prussian blue screen-printed working electrode (PB-SPWE) was fabricated for continuous detection of free chlorine compound (free-Cl) in water samples from swimming pools. Carbon and Prussian blue were deposited on a flexible substrate using a screen-printing technique. Different screen-printed PB-SPWEs demonstrated the good reproducibility of the electrode fabrication and were further incorporated with a lab-made flow cell in a flow injection (FI) analysis system. The electrochemical response via Prussian blue reaction was recorded at a potential of 50 mV vs. Ag/AgCl. High-throughput analysis was achieved by continuous injection of a standard NaOCl solution, and 336 measurements could be completed in 5.6 h. Under optimal conditions, the PB-SPWE was applied to determine free-Cl in several swimming pool water samples without any sample preparation. The results not only were in good agreement with the standard DPD (N,N-diethyl-p-phenylenediamine) spectrophotometric method, but also presented excellent accuracy (recovery = 80.0 +/- 0.2 to 109 +/- 1%) and precision (test by Wilcoxon Signed-Ranks) in measuring free-Cl concentrations. In summary, these results supported that the combination of PB-SPWE and FI-AMP can be applied to monitor swimming pool water quality, which can minimize the risk to swimmers' health. (c) 2021 Elsevier Ltd. All rights reserved.