- Trace metals in marine ecosystems
- Development of analytical methods for environmental samples
- Development of simple and affordable optical and electrochemical sensing systems
- Environmental Chemistry in general
My academic background is strongly oriented to Environmental Analytical Chemistry. In my current project at the Ocean Lab at Jacobs University and at the ICBM at the Carl von Ossietzky Universität Oldenburg, I am working on the development of colorimetric sensors for the quantification of manganese in the marine and related environments, for example, in porewaters from sandy beaches of the island of Spiekeroog.
Manganese (Mn) is the 11th element in abundance in the earth´s crust and an important element in marine sediments. It is a trace metal in the ocean and an essential trace nutrient and it is involved in the process of mineralization of organic matter. For all these reasons, manganese plays a key role in marine biogeochemical cycles, and assessing the concentration and speciation of this element is an essential issue to understand redox reaction-transport processes in sedimentary deposits.
Although instrumental techniques with excellent analytical performance are available for its quantification, these have the major drawback of requiring expensive instrumentation and consumables, as well as highly qualified personnel. Besides, these methods do not allow for measurements to be performed in the field.
Considering all these aspects, a rapid, cost-effective, field-based method for the quantification of Mn in pore waters will allow for direct monitoring on-site as well as for the assessment at substantially higher spatial and temporal resolution than would be possible using traditional methods. Therefore, my proposal is based on the immobilization of colorimetric reagents for Mn on plastic test strips. Upon contact with the sample, a chemical reaction between the specific reagent and the analyte takes place, which is evidenced by a color change. The intensity of this change is quantified and related to the concentration of Mn in the sample by analysis of digital images of the sensors taken with a common smartphone.
To prove the applicability of the sensors to real samples, a rigorous study of the effect of potential interferents is carried out. Also, the sensors are tested on real samples collected by Dr. Koschinsky´s group in previous research cruises (for example, to the Amazon estuary) and on porewater samples collected in the north beach of the Island of Spiekeroog in the frame of the DynaDeep project (DFG). The results are compared to the ones obtained using traditional spectroscopic techniques (ICP).
Pedre, I.*, Méndez De Leo, L., González, G. A. (2019). Cu2+-ion sensitive Surface on graphite electrodes. Analytical and Bioanalytical Chemistry 411(29):7761-7770. https://doi.org/10.1007/s00216-019-02142-0
Pedre, I., Battaglini, F., González, G. A. (2018). Disposable electrochemical sensor for rapid determination of ethyl xanthate in the mining industry Electroanalysis 30:2589-2596. https://doi.org/10.1002/elan.201800419
Pedre I., Cifuentes G., Sánchez-Loredo M. G., González G. A. (2016). Book chapter Técnica de detección electroquímica de tiourea presente en baños de electrorrefinería de cobre por medio de sensores conteniendo nanopartículas de plata (Electrochemical determination of thiourea in copper-refinery baths using sensors containing silver nanoparticles) inNuevos Procesos y Materiales para la Detección y Eliminación de Contaminantes en Agua (New processes and materials for the detection and elimination of hazardous substances in water). Moura Bernardes, A., Cifuentes Molina, G., Siqueira Rodrigues, M. A. and Rodríguez, M. A. (eds.)
Pedre, I., Méndez De Leo, L., Sánchez-Loredo, M. G., Battaglini, F., González, G. A. (2016). Electrochemical sensor for thiourea focused on metallurgical applications of copper. Sensors and Actuators B 232:383-389.https://doi.org/10.1016/j.snb.2016.03.154
Sciscenko I., Pedre I., Hunt A., Bogo H., González G. A. (2016). Determination of a typical additive in zinc electroplating baths. Microchemical Journal 127:226-230. https://doi.org/10.1016/j.microc.2016.03.015
Pedre, I., Battaglini, F., Labrada Delgado, G. J., Sánchez-Loredo, M. G., González, G. A. (2015). Detection of thiourea from electrorefining baths using silver nanoparticles-based sensors. Sensors and Actuators B 211:515-522.