Filtrating-bulk passive sampling for elemental fractionation in atmospheric deposition

We have recently published the paper entitled "Fractionation of trace elements in total atmospheric deposition by filtrating-bulk passive sampling" in the journal Talanta. We have developed and validated a new simple and effective methodology for fractionation of soluble and insoluble forms of trace elements in total atmospheric deposition. The proposed methodology is based on the modification of a standard total deposition passive sampler by integrating a quartz fiber filter that retains the insoluble material, allowing the soluble fraction to pass through and flow to a receiving bottle. The quartz filter containing the insoluble fraction and the liquid containing the soluble fraction are then separately assayed by standardized ICP–MS protocols. The proposed atmospheric elemental fractionation sampler (AEFS) was validated by analyzing a Coal Fly Ash reference material with proper recoveries, and tested for field fractionation of a set of 10 key trace elements in total atmospheric deposition at the industrial area of Puchuncaví–Ventanas, Chile. The AEFS was proven useful for pollution assessment and also to identify variability of thes oluble and insoluble fractions of the selected elements within the study area, improving the analytical information attainable by standard passive samplers for total deposition without the need of using sophisticated and high cost wet-only/dry-only collectors.

New publication about screen printed electrode characterization

Our research group has just published a paper entitled "Characterisation of screen-printed gold and gold nanoparticle-modified carbon sensors by electrochemical impedance spectroscopy", in the Journal of Electroanalytical Chemistry. Gold-based screen-printed electrodes have been characterised by electrochemical impedance spectroscopy (EIS) to better understand their behaviour in electroanalytical applications, particularly in the anodic stripping voltammetry of Hg(II). After a first exploration by cyclic voltammetry, impedance spectra of gold-based screen-printed sensors were recorded in 0.1 M HCl electrolyte solution, in the presence of dissolved oxygen and with no electrochemical pre-treatment of the surface. The spectra demonstrated the differences in the interfacial characteristics of each kind of sensor. Structural changes in the surface of SPGEs caused by amalgam formation in the presence of Hg(II) were investigated by EIS. The results obtained were used to elucidate the implications for using the sensor in the stripping voltammetric determination of Hg(II) in environmental samples.

Research work in Valparaíso, Chile

Seven members of the group are currently in Chile for a two weeks stay. We`re sharing research results and carrying out environmental sampling and monitoring campaigns around Valparaíso, with colleagues from Universidad Técnica Federico Santa María and UEx.

Analyzing environmental pollution in snow at the Andes, Chile

The journal "Atmospheric Environment" has recently published our results about the evaluation of the impact of Santiago de Chile urban pollution on trace elements levels content in snow precipitation at the nearby heights of Cerro Colorado in Central Andes.

Voltammetric determination of mercury on screen printed electrodes modified with gold nanoparticles

The journal "Sensors and Actuators B: Chemical" has just accepted for publication our work about the voltammetric stripping determination of mercury on gold nanoparticles modified screen printed electrodes, with application to environmental water samples. Go to "Selected Publications" for details.

Our research group in university TV "Onda campus"

Operación Comprometida - Octubre con la Ecología from ondacampus on Vimeo.

Celebrating Chemistry Year

We are proudly celebrating the International Year of Chemistry

http://www.chemistry2011.org/