Simultaneous Detection of Peracetic Acid and Hydrogen Peroxide by Amperometry at Pt and Au Electrodes

Abstract

Based on preliminary voltammetric investigations at both Pt and Au electrodes in aqueous solutions buffered at different pH values in the range 0 -10, two possible profitable triple-pulse amperometric approaches were developed for determining simultaneously peroxyacetic acid (PAA) and hydrogen peroxide present in the same samples. At both surfaces a pulsed waveform applied at rotating-disc electrodes was adopted to take advantage on one hand of the optimized signal reproducibility achieved by this potential multistep antifouling approach and on the other hand of the constant thickness of the diffusion layer, which is necessary when the recording of time-independent currents is desired. At a rotating-disc Pt electrode an anodic selective signal was indeed recorded for H 2 O 2 alone, while PAA contents could be inferred only from the difference of convenient signals, since at all pHs explored its sole cathodic reaction could be observed at potentials coincident with those proper for the reduction of H 2 O 2 too. The same pulse approach at Au electrodes instead provided totally independent signals for the two analytes considered, thus proving to be suitable for their independent detection. In fact, H 2 O 2 alone undergoes anodic oxidation also at this surface, while the reduction of PAA occurs at potentials less cathodic than those required for H 2 O 2 . At both electrodes, the best results turned out to be achieved at pH 0 in terms of both precision (AE 2 -4%) and detection limits (0.2 -0.3 mM), as well as of linear range which extended for about three orders of magnitude. The kinetics of the equilibrium involving the generation of H 2 O 2 from the reaction of PAA with water was also evaluated, since it was suspected of making unreliable the proposed amperometric approaches.

Simultaneous Detection of Ascorbic Acid and Hydrogen Peroxide by Flow‐Injection Analysis with a Thin Layer Dual‐Electrode Detector

“…Hydrogen peroxide underwent instead both anodic and cathodic processes, in agreement with previous reports [27,43]. In particular, at all pHs the anodic process detected at Pt and Au electrodes occurred at potentials quite close to those required for the formation onto electrode surfaces of the well known thin "metal oxide" layer that mediates H 2 O 2 oxidation [44].…”

“…In spite of these drawbacks, the fact that AA and H 2 O 2 are both electroactive compounds makes quite attractive their detection by electrochemical methods, in view of their inherent selectivity and sensitivity. Moreover, they offer in situ and instantaneous multicomponent measurements, almost always in the same environment in which the analytes of interest normally exist, with on line capabilities and low-cost instrumentation.. On the other hand, the possibility of adopting successfully specific approaches for tackling the electroanalytical monitoring of reciprocally interfering species was already rather abundantly reported [12,14,[26][27][28][29][30].…”

Peracids in water treatment: A critical review

“…Finally, simultaneous determination of H 2 O 2 and PAA (with a detection limit of 0.2-0.3 mM, approx. 15-23 mg/L) was studied by a triple pulse amperometric approach involving Pt and Au electrodes [75].…”

A High-Throughput Microtiter Plate Based Method for the Determination of Peracetic Acid and Hydrogen Peroxide

“…While these chromatographic methods are able to quantitate both peracetic acid and hydrogen peroxide, like nearly all chromatographic methods, large numbers of solutions cannot be rapidly processed. In addition to these methods, potentiometric and amperometric methods have also been developed [20] , [21] , [22] , [23] . However, most of the electrical signal based methods can only determine peracetic acid and not hydrogen peroxide; have limits in sensitivity, dynamic range or specificity; may require frequent calibrations and require specialized or custom made materials.…”