Publications by authors named "Gabriel Gustinelli Arantes de Carvalho"
Desferrioxamine (DFO) and diethylenetriaminepentaacetic acid (DTPA) conjugated with silica gel (IDFOSG and IDTPASG, respectively) were evaluated as adsorbents for chromium in aqueous solutions. Different parameters affecting adsorption such as pH, sorbent dosage, contact time, sample volume and potential of interfering ions have been optimized. The optimum pH for chromium binding was 4 for 100 mg of adsorbents at 5 min of table shaking with 5 mL sample volume of chromium solutions.
View Article and Find Full Text PDFFemtosecond laser-induced breakdown spectroscopy (fs-LIBS) has been used for the first time for quantitative determination of nutrients in plant materials from different crops. A highly heterogeneous population of 31 samples, previously analyzed by inductively coupled plasma optical emission spectroscopy, covering a wide range of matrices was interrogated. To tackle the analysis, laser-induced plasmas under argon atmosphere of pellets prepared from sieved cryogenically ground leaves were studied.
View Article and Find Full Text PDFMercury occurrence was evaluated in samples of edible muscle tissue of 27 blue sharks (Prionace glauca) caught in the Atlantic Ocean, adjacent to the south and southeastern Brazilian coast, indicating a slight increase in comparison with previous data obtained for the same studied area and being higher than those fish caught at different sites of the Atlantic Ocean. Total Hg concentrations ranged from 0.46 to 2.
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- Laser induced breakdown spectrometry (LIBS) is identified as a viable method for analyzing macro and micronutrients in plant pellets, yet proper sample preparation is crucial.
- The study compares cryogenic grinding and planetary ball milling techniques to prepare leaves for pellet formation, noting the impact of particle size on chemical properties and pellet characteristics.
- Results show that appropriate grinding conditions vary by plant species, with finely ground pellets enhancing LIBS emission signal intensity by up to 50%.
An analytical procedure for the determination of Hg in otter (Lontra longicaudis) feces was developed, to separate fish scales for the identification of the animal diet. Samples were washed with ultra-pure water and the suspension was sampled and transferred for digestion. The solubilization was performed with nitric-perchloric acid mixture, and detection carried out by the atomic fluorescence spectrometry (AFS).
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