This suggests that flowing conditions has little effect on pH. This is further illustrated in Figure where two calibrations of gold oxide reduction potential minima versus pH for both hydrodynamic conditions are plotted and overlaid and exhibit very similar behaviour within the investigated pH range. Once the effects of flowrate on desired pH had been compensated for, electrochemical analysis was then undertaken. Hypochlorous acid was selected as an analyte of interest due to its importance is water sterilisation. A stock solution of 5.3 ppm was prepared and used to assess the impacts of flowrate.