In this work, microwave-induced plasma optical emission spectrometry was applied for multielement determination in South American wine samples. The analytes were determined after acid digestion of 47 samples of Brazilian and Argentinian wines. Then, logistic regression, support vector machine, and decision tree for exploratory analysis and comparison of these algorithms in differentiating red wine samples by region of origin were carried out.
View Article and Find Full Text PDFRising interest in ellagic acid (EA) present in functional foods is supported by its antimutagenic, anticarcinogenic, antiviral, antibacterial and antioxidative effects. The present approach presents for the first time the determination of ellagic acid and other phenolics in wines by miniaturized solid phase extraction prior to capillary zone electrophoresis (CZE) with UV. The extraction was performed using a home-made miniaturized pipette tip column.
View Article and Find Full Text PDFMercury (Hg) is a major environmental pollutant that can be disposed to the environment by human activities, reaching crops like vineyards during irrigation with contaminated waters. A 2-year study was performed to monitor Hg variations during reproductive and vegetative stages of vines after Hg supplementation. Variations were focused on total Hg concentration, the molecular weight of Hg fractions and Hg-proteins associations in roots, stems and leaves.
View Article and Find Full Text PDFA novel methodology is presented for the enhanced electrochemical detection of oleuropein in complex plant matrices by Graphene Oxide Pencil Grahite Electrode (GOPGE) in combination with a buffer modified with a Natural Deep Eutectic Solvent, containing 10% (v/v) of Lactic acid, Glucose and H O (LGH). The electrochemical behavior of oleuropein in the modified-working buffer was examined using differential pulse voltammetry. The combination of both modifications, NADES modified buffer and nanomaterial modified electrode, LGH-GOPGE, resulted on a signal enhancement of 5.
View Article and Find Full Text PDFA high performance liquid chromatography coupled with atomic fluorescence spectrometry method for the determination of thimerosal (sodium ethylmercury thiosalicylate, C9H9HgNaO2S), ethylmercury, and inorganic mercury is proposed. Mercury vapor is generated by the post-column reduction of mercury species in formic acid media using UV-radiation. Thimerosal is quantitatively converted to Hg(II) followed by the reduction of Hg(II) to Hg(0).
View Article and Find Full Text PDFAn approach to understand vines (Vitis vinifera) defense mechanism against heavy metal stress by isolation and determination of Hg-phytochelatins (PCs) complexes was performed. PCs are important molecules involved in the control of metal concentration in plants. PCs complex toxic metals through -SH groups and stores them inside cells vacuole avoiding any toxic effect of free metals in the cytosol.
View Article and Find Full Text PDFConcerns regard watering crops with Hg contaminated waters have arisen worldwide recently. In these sense Hg uptake by Vitis vinifera L. cv.
View Article and Find Full Text PDFA simple non-chromatographic method for the determination of mercury (Hg(2+)), methylmercury (MeHg(+)), dimethylmercury (Me(2)Hg), and phenylmercury (PhHg(+)) employing atomic fluorescence spectrometry (AFS) as detection technique was developed. Mercury species showed a particular behavior in the presence of several reagents. In a first stage SnCl(2) was employed for Hg(2+) determination; in a second step, [Hg(2+)+PhHg(+)] concentration was determined using SnCl(2) and UV radiation.
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