Diseño de plataformas de estado sólido para la determinación simultánea de cromo III y VI [Design of solid-state platforms for the simultaneous determination of Cr III and VI]

Speciation analyses of an element allow obtaining information on the concentrations of its chemical forms present in specific environments. Chromium is largely distributed in industrial effluents often at acid pH, with the relevant oxidation states Cr (III) and Cr (VI) having contrasting impacts on the environment and health. While trivalent chromium is relatively harmelss and is an essential trace element, the hexavalent form is highly toxic. Therefore, it is important to know which species is stable, and pollution monitoring requires robust sensors that tolerate very acid pH levels. We investigate carbon-based screen-printed electrodes (SPEs), which are practical, disposable and low-cost devices and are easy to tailor to specific uses. Here, we add a specific ionophore, cuprizone, i.e. (cyclohexanone)oxaldihydrazone by electrodeposition to an electrode consisting of graphite bound with polyvinylbutyral (PVB). This matrix exhibits sufficient resistance to the acid working conditions. The combination of the analytical yield and the enormous possibilities of SPEs open the door to new sensor designs meeting the current needs of environmental and pharmacological chemical analysis.