Analytical contributions to the characterization and determination of nanoparticles

Actualmente nos encontramos en plena expansión de la Nanociencia y Nanotecnología. Millones de toneladas de nanopartículas (NPs) se producen anualmente con fines comerciales o como subproductos de la actividad humana. La creciente producción y el uso de nanomateriales conducirán a su acumulación, generando importantes implicaciones negativas para la salud humana y el medio ambiente [1]. Uno de los roles de la Química Analítica en este contexto es el análisis y caracterización de dichas nanopartículas. Si bien puede afirmarse que hay un déficit de técnicas analíticas que permitan su caracterización rápida, la situación se agrava aún más cuando se pretenden determinar en matrices complejas como medioambientales y biológicas. En esta tesis doctoral se ha abordado, por tanto, la síntesis y caracterización de nanoestructuras de naturaleza metálica (Au y Ag) y de carbono (CNTs), así como el desarrollo de metodologías que permitan su determinación en matrices ambientales y biológicas

Caracterización rápida de nanotubos de carbono mediante un espectrometro Ramana portátil

II Encuentro sobre nanociencia y nanotecnología de investigadores y tecnólogos de la Universidad de Córdoba. NANOUC

Influencia del estado de agregación en el espectro Raman de nanotubos de carbono monocapa (SWNTs)

III Encuentro sobre Nanociencia y Nanotecnología de Investigadores y Tecnólogos Andaluce

Potencial de las nanopartículas híbridas en química analítica

III Encuentro sobre Nanociencia y Nanotecnología de Investigadores y Tecnólogos Andaluce

Determinación rápida de nanopartículas de oro en muestras ambientales y biológicas

II Encuentro sobre nanociencia y nanotecnología de investigadores y tecnólogos de la Universidad de Córdoba. NANOUC

Monolithic Solid Based on Single-Walled Carbon Nanohorns: Preparation, Characterization, and Practical Evaluation as a Sorbent

A monolithic solid based solely on single walled carbon nanohorns (SWNHs) was prepared without the need of radical initiators or gelators. The procedure involves the preparation of a wet jelly-like system of pristine SWNHs followed by slow drying (48 h) at 25 C. As a result, a robust and stable porous network was formed due to the interaction between SWNHs not only via - and van der Waals interactions, but also via the formation of carbon bonds similar to those observed within dahlia aggregates. Pristine SWNHs and the SWNH monolith were characterized by several techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), confocal laser scanning microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and nitrogen intrusion porosimetry. Taking into account the efficiency of carbon nanoparticles in sorption processes, the potential applicability of the SWNH-monolith in this research field was explored using toluene; m-, p-, and o-xylene; ethylbenzene; and styrene, as target analytes. Detection limits were 0.01 g L�����1 in all cases and the inter-day precision was in the interval 7.4–15.7%. The sorbent performance of the nanostructured monolithic solid was evaluated by extracting the selected compounds from different water samples with recovery values between 81.5% and 116.4%

Unmodified cellulose filter paper, a sustainable and affordable sorbent for the isolation of biogenic amines from beer samples

While current trends in Green Analytical Chemistry aim at reducing or simplifying sample treatment, food usually comprises complex matrices where direct analysis is not possible in most cases. In this context, sample treatment plays a pivotal role. Biogenic amines are naturally formed in many foodstuffs due to the action of microorganisms, while their presence has been associated with adverse health effects. In this work, the extraction of seven biogenic amines (cadaverine, histamine, phenylethylamine, putrescine, spermidine, spermine, and tyramine) from beer samples has been simplified using laboratory filter paper as sorbent without any further modification. The analysis of the eluates by direct infusion mass spectrometry reduces the time of analysis, increasing the sample throughput. This simple but effective method enabled the determination of the analytes with limits of detection as low as 0.06 mg L−1 and relative standard deviations better than 11.9%. The suitability of the method has been assessed by analyzing eight different types of beers by the standard addition method