RT info:eu-repo/semantics/article T1 Normal or parallel configuration in spectroelectrochemistry? Bidimensional spectroelectroanalysis in presence of an antioxidant compound A1 Olmo Alonso, Fabiola A1 Garoz Ruiz, Jesús A1 Heras Vidaurre, Aránzazu A1 Colina Santamaría, Álvaro K1 Bidimensional Spectroelectrochemistry K1 Adrenaline K1 Ascorbic acid K1 Quantitative Analysis K1 Química analítica K1 Chemistry, Analytic AB This work demonstrates how the way a chemical system is sampled plays a key role in spectroelectroanalysis, illustrated by the quantification of an analyte in presence of an antioxidant compound. For this purpose, bidimensional spectroelectrochemistry experiments were performed using epinephrine as the model analyte and ascorbic acid as antioxidant and interfering compound, as a proof of concept. This is the first time that three calibration curves are obtained simultaneously on a single spectroelectrochemistry data set, one for the electrochemical signal and two for the optical responses in normal and parallel configurations. The differences between the two optical arrangements, that are related to the diffusion process which is an essential feature for the spectroelectrochemical detection of compounds, have been experimentally demonstrated. As can be observed, the spectral signal in parallel configuration allows us to obtain the best analytical results, since in this configuration only the first micrometers of the solution adjacent to the electrode surface are sampled, thus removing the interfering effect of the antioxidant compound. This fact does not occur with either the electrochemical signal or the spectral response in normal configuration. Furthermore, it has been shown that the parallel configuration provides better results than the normal configuration in terms of sensitivity. In summary, epinephrine is successfully detected in a simple and effective way, even in the presence of a direct antioxidant compound such as ascorbic acid at different concentrations levels, which makes spectroelectrochemistry a good choice for quantitative analysis. PB Elsevier SN 1572-6657 YR 2023 FD 2023-04 LK http://hdl.handle.net/10259/7693 UL http://hdl.handle.net/10259/7693 LA eng NO Authors acknowledge the financial support given by Ministerio de Ciencia e Innovación and Agencia Estatal de Investigación (MCIN/AEI/ 10.13039/501100011033, PID2020-113154RB-C21) and Ministerio de Ciencia, Innovación y Universidades (Grant RED2018-102412-T). Fabiola Olmo is grateful for the contract funded by Junta de Castilla y León, the European Social Fund, and the Youth Employment Initiative. DS Repositorio Institucional de la Universidad de Burgos RD 23-nov-2024