UV/Vis absorption spectroelectrochemistry (SEC) is a multi-response technique that has
been commonly used for the characterization of materials and the study of reaction mechanisms.
However, it has been scarcely used for quantitative purposes. SEC allows us to obtain two analytical
signals simultaneously, yielding a dual sensor in just one experiment. In the last years, our group
has developed new devices useful for analysis. In this work, a SEC device in parallel configuration,
based on optical fibers fixed on screen-printed electrodes, was used to determine isoprenaline
in a commercial drug, using both, the electrochemical and the spectroscopic signals. In this
commercial drug, isoprenaline is accompanied in solution by other compounds. Among them is
sodium metabisulfite, an antioxidant that strongly interferes in the isoprenaline determination. A
simple pretreatment of the drug sample by bubbling wet-air allows us to avoid the interference of
metabisulfite. Here, we demonstrate again the capabilities of UV/Vis absorption SEC as double sensor
for analysis and we propose a simple pretreatment to remove interfering compounds.
