Romina Brasca

Five-Membered Aromatic Heterocycles in Diels-Alder Cycloadditio Reactions: Theoretical Studies as a Complement of the Experimental Researches

Fil: Brasca, Romina. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Santa Fe; Argentina

Highly Selective and Ultrasensitive Turn-on Luminescence Chemosensor for Mercury (II) Determination Based on the Rhodamine 6G Derivative FC1 and Au Nanoparticles

A method for the detection and quantitation of Hg2+ in aqueous samples by fluorescence spectroscopy is presented. It consists of a turn-on sensor developed by coupling Gold nanoparticles (AuNPs) with the rhodamine 6G derivative FC1, in which the response is generated by a mercury-induced ring-opening reaction. The AuNPs were included in order to improve the sensitivity of the method towards the analyte, maintaining its high selectivity. The method was validated in terms of linearity, precision and accuracy, and applied to the quantitation of Hg2+ in Milli-Q and tap water with and without spiked analyte. The limit of detection and quantitation were 0.15 μg·L−1 and 0.43 μg·L−1, respectively, constituting a substantial improvement of sensitivity in comparison with the previously reported detection of Hg2+ with free FC1.

Spectroscopic behavior of loratadine and desloratadine in different aqueous media conditions studied by means of TD-DFT calculations

In this study, we explained the influence of the stepwise protonation of two antihistaminic drugs on their experimental absorption spectra. We demonstrated the capability of the TD-CAM-B3LYP method, combined with a polarizable continuum model, to produce good performance for the calculated spectra. The lowest energy transitions and the molecular orbital plots were analyzed in detail. The calculated UV spectra are proposed as potential alternatives to initialize the well-known MCR-ALS algorithm, especially when the spectra of the pure analytes are not available. Moreover, it can be a useful strategy for planning an experimental methodology oriented to multiway analysis when the drug species exhibit acid-base properties.

Multiway Calibration Approaches for Quality Control of Food Samples

Abstract In this chapter, the state-of-the-art multiway calibration methods used to perform quality control of food samples are discussed. Several examples of multidimensional chemometric methods developed to directly quantitate analytes of interest in complex systems even in the presence of interferences, which is known as the “second-order advantage,” are presented. Practical analytical applications based on second-order data generation with instrumental techniques, that is, fluorescence spectroscopy, high-performance liquid chromatography and capillary electrophoresis, and data processing with proper algorithm such as parallel factor analysis (PARAFAC), multivariate curve resolution alternating leastsquares (MCR-ALS), unfolded partial least-squares/residual bilinearization (U-PLS/RBL), and alternating trilinear decomposition (ATLD), are described.