Abstract:
Due to desirable environmental reasons, peroxides have replaced halogenated
substances for disinfection purposes in the food and beverage industry. However, cost
issues and the requirement to completely remove these agents after disinfection
necessitates simple, low-cost and sensitive test methods with a wide dynamic range and
on-line capability. The development and performance of such a method is detailed in
this thesis. The novelty of this work was in the simplified production of the sensor by
pre-mixing all active components before application onto a screen-printed graphite base
electrode in a single step.
Having established the principle of pre-mixing all the components, the proportions were
optimised with regard to a balance between cost and required performance in the
industrial application. Once this had been established, the performance and stability was
evaluated in the laboratory, a comparative study was performed against other methods
for hydrogen peroxide determination and finally the sensor was demonstrated to work in
a small-scale industrial field trial.
Some of the available mass-production processes for the sensor were considered for
suitability and a recommendation made. The relative analytical performances of sensors
produced manually and by the recommended process were compared to their visual
appearance under a microscope and a possible quality control process suggested for the
manufacturing stage.
Finally, a scanning electrochemical microscope was commissioned and a method for
producing ultramicroelectrodes for use with it developed. This was then used to study
the variation of the sensor surface coating with the aim of facilitating the optimisation
of the composition, production and quality control processes.