Continuous Detection of Hypochlorous Acid/Hypochlorite for Water Quality Monitoring and Control

Abstract

This work demonstrates the continuous detection of hypochlorite in tap water using bare platinum electrodes. Continuous amperometric operation is possible for several days in spite of Pt oxide formation. Pt oxides are formed both by simple contact of the Pt surface with a hypochlorite solution, and during the electrochemical reduction of hypochlorite ions. Pt oxide and hypochlorite reduction processes may overlap at moderate to high hypochlorite concentrations, resulting in erroneous concentration readings. Passivated cathodes are reactivated by cathodic cycling in supporting electrolyte. Electrode protection using suitable membranes may extend the useful life time of Pt electrodes, particularly in complex samples.

A cyanine-based near-infrared fluorescent probe for highly sensitive and selective detection of hypochlorous acid and bioimaging

“…At present, some methods such as electroanalysis [18,19], chemiluminescence [20,21], and iodometric [22], spectrophotometry [23,24] have been developed for HOCl detection, but there are still limits in practical applications [25]. Compared to other detection methods, fluorescence-based methods show high sensitivity and selectivity, and real-time monitoring and bioimaging of analytes [26][27][28][29].…”

Electrochemical detection of free chlorine at inkjet printed silver electrodes

“…In particular, amperometry and potential sweep techniques have been extensively involved in the direct determination of free chlorine using its electrochemical oxidation or reduction properties [15][16][17][18][19][20][21][22][23]. The type of electrode materials used for chlorine analysis include platinum [19,[21][22][23][24][25], gold [26,27], glassy carbon [15], graphite [16], CNT composite electrodes [21], poly-melamine modified electrodes [28], AuNPs/ PEDOT nanocomposite [29] and poly MnTAPP-nano Au film modified electrodes [30]. However, the determination of free chlorine using inkjet printed silver electrodes has not been reported to date.…”

Kinetic parameters for anodic oxidation of hypochlorite ion on Pt and Pt oxide electrodes in alkaline solution

“…The anodic electrode reaction of chlorine has been studied widely with respect to the industrial chlor-alkali process, fuel cell, and sensor of the environment analysis [1][2][3][4]. The typical mechanisms taking place on metallic surfaces are explained as [5,6]:…”