Determinação da composição química do molusco Anadara notabilis encontrado em Galinhos no Rio Grande do Norte

Given the large existing biodiversity in the Brazilian coast, where many species are still little known, even under the nutritional aspect, and considering that bivalve molluscs are constituted by a natural resource of well accepted by the population, chose the bivalve Anadara notabilis, it was not found in the literature any nutritional or toxicological information about it and because its size is much larger than other species of mollusks commonly found in this region. Were studied moisture, ash, protein, macro and micro minerals, and metal ions of toxicological significance. All analytical determinations followed the standards of the Institute Adolfo Lutz. The protein determination was performed by the Kjeldahl method. All metal ions were determined by optical emission spectroscopy with inductively coupled plasma (ICP-OES) method described by USEPA 6010C. The results showed that Anadara notabilis can be introduced into food for human beings, in view of its mineral wealth. Noteworthy among the macronutrients phosphorus and magnesium showed that their values in mg / kg 918.7 and 586.7. With regard to micronutrients stand out with this iron 586.7 mg / kg and zinc with 12.31 mg / kg. Was not found high content of metal contaminants to this mollusc, which would prevent their use, only this chromium 0.7 mg / kg above the value established by Brazilian legislation. The results will certainly be very useful in future studies of nutrition and to build a table of chemical composition of Brazilian foods

Determinação do teor de cálcio através da termogravimetria, em medicamentos utilizados no tratamento da osteoporose: um estudo comparativo

The present study utilized the thermogravimetry (TG) and optical emission spectroscopy with inductively coupled plasma - ICP / OES to determine the calcium content in tablets of carbonate, citrate and calcium lactate used in the treatment of osteoporosis. The samples were characterized by IR, SEM, TG / DTG, DTA, DSC and XRD. The thermal analysis evaluated the thermal stability and physical-chemical events and showed that the excipients influence the decomposition of active ingredients. The results of thermogravimetry indicated that the decomposition temperature of the active CaCO3 (T = 630.2 °C) is lower compared to that obtained in samples of the tablets (633.4 to 655.2 °C) except for sample AM 2 (Ti = 613.8 oC). In 500.0 °C in the samples of citrate and calcium lactate, as well as their respective active principles had already been formed calcium carbonate. The use of N2 atmosphere resulted in shifting the initial and final temperature related to the decomposition of CaCO3. In the DTA and DSC curves were observed endo and exothermic events for the samples of tablets and active ingredients studied. The infrared spectra identified the main functional groups in all samples of active ingredients, excipients and tablets studied, such as symmetric and asymmetric stretches of the groups OH, CH, C = O. Analysis by X-ray diffraction showed that all samples are crystalline and that the final residue showed peaks indicative of the presence of calcium hydroxide by the reaction of calcium oxide with moisture of the air. Although the samples AM 1, AM 2, AM 3 and AM 6 in their formulations have TiO2 and SiO2 peaks were not observed in X-ray diffractograms of these compounds. The results obtained by TGA to determine the calcium content of the drugs studied were satisfactory when compared with those obtained by ICP-OES. In the AM 1 tablet was obtained the content of 35.37% and 32.62% for TG by ICP-OES, at 6 AM a percentage of 17.77% and 16.82% and for AM 7 results obtained were 8.93% for both techniques, showing that the thermogravimetry can be used to determine the percentage of calcium in tablets. The technique offers speed, economy in the use of samples and procedures eliminating the use of acid reagents in the process of the sample and efficiency results.

A theoretical study of the A(2)Sigma(+)-X-2 Pi system of the SiP molecule

The A (2)Sigma(+) and X(2)Pi electronic states of the SiP species have been investigated theoretically at a very high level of correlation treatment (CASSCF/MRSDCI). Very accurate potential energy curves are presented for both states, as well as the associated spectroscopic constants as derived from the vib-rotational energy levels determined by means of the numerical solution of the radial Schrodinger equation. Electronic transition moment function, oscillator strengths, Einstein coefficients for spontaneous emission, and Franck-Condon factors for the A(2)Sigma(+)-X(2)Pi system have been calculated. Dipole moment functions and radiative lifetimes for both states have also been determined. Spin-orbit coupling constants are also reported. The radiative lifetimes for the A(2)Sigma(+) state, taking into account the spin-orbit diagonal correction to the X(2)Pi state, decrease from a value of 138 ms at v' = 0 to 0.48 ms at v' = 8, and, for the X(2)Pi state, from 2.32 s at v = 1 to 0.59 s at v = 5. Vibrational and rotational transitions are expected to be relatively strong.

Radiative association of Ti and O atoms

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Black and green pigments based on chromium-cobalt spinels

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Electrochemical study of TEOS, TEOS/MPTS, MPTS/MMA and TEOS/MPTS/MMA films on tin coated steel in 3.5% NaCl solution

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Correlation between the spectroscopic and structural properties with the occupation of Eu3+ sites in powdered Eu3+-doped LiTaO3 prepared by the Pechini method

In this work we studied the structural and optical properties of lithium tantalate (LiTaO3) powders doped with Eu3+ ions. We have examined the different sites occupied by the rare earth ion through the correlation of the DRX data analyzed with the Rietveld method and some spectroscopic parameters derived from the Eu3+ luminescence. Adirect relation was established between the lattice parameters and the occupation fraction of Eu3+ in each LiTaO3 site. The occupation fraction was set as the relative population of Eu3+ ions for each site obtained by means of the intensity, baricenter, and the spontaneous emission coefficients of the D-5(0)-> F-7(0) transitions. We concluded that the unit cell parameter a presents the same behavior of the Eu3+ occupation fraction in Ta5+ sites as a function of the Eu3+ content in LiTaO3. The same was observed for the variation in Eu3+ occupation fraction in the Li+ site and the unit cell parameter c with the Eu3+ content. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3204967]

Solid state reactions in the platinum-mercury system

Thermogravimetry, Differential Scanning Calorimetry and other analytical techniques (Energy Dispersive X-ray Analysis; Scanning Electron Microscopy; Mapping Surface; X-ray Diffraction; Inductively Coupled Plasma Atomic Emission Spectroscopy and Cold Vapor Generation Atomic Absorption Spectroscopy) have been used to study the reaction of mercury with platinum foils. The results suggest that, when heated, the electrodeposited Hg film reacts with Pt to form intermetallic compounds each having a different stability, indicated by at least three mass loss steps. Intermetallic compounds such as PtHg4, PtHg and PtHg2 were characterized by XRD. These intermetallic compounds were the main products formed on the surface of the samples after partial removal of bulk mercury via thermal desorption. The Pt(Hg) solid solution formation caused great surface instability, attributed to the atomic size factor between Hg and Pt, facilitating the acid solution's attack to the surface.

A flow-injection-ICP system sequential multielemental analysis with simultaneously mercury(II) preconcentration step

A flow-injection system for multielemental analysis with a mercury(II) preconcentration step using a resin Chelite-S(R)(Serva Feinbiochemica Heidelberg, Part No. 41709) packed minicolumn by inductively coupled plasma atomic emission spectroscopy is described. A mercury reductive elution procedure with a mixture of SnCl2/HCl was used, which allows use of 6 mol/L HCl solution instead of concentrated hydrochoric acid. The main parameters related to ICP operation, such as radio frequency power (950-1750 W), auxiliary argon flow (0.0-1.5 L/min) and spray chamber nebulizer pressure (15-35 psi), were studied. Optimization of the FIA system was reached by defining the best eluent carrier stream (1.4-2.8 mL/min), Hgdegrees carrier stream (10-40 mL min(-1)), loading time (0.5-4.0 min), sample flow rate (1.25-10.0 mL/min), temperature of reactor gas liquid separator (GLS) (25-75 degreesC) and eluent volume (50-350 muL). Throughput is around 30 samples per hour for analytical solutions within the range 50-2500 ng Hg(II)/L. Results from certified material showed good precision (RSD < 3%, n = 12) and no statistical difference was observed for real samples analyzed by AAS and by the proposed system.

Plasma polymerized hexamethyldisiloxane: Discharge and film studies

Films were grown in hexamethyldisiloxane (HMDS)-argon mixtures in a diode sputtering system with a gold cathode. Quantitative optical emission spectroscopy (OES)-actinometry revealed that the electron density or mean electron energy (or both) increased with increasing Ar concentrations in the gas feed. Increasing concentrations of Ar produced greater sputtering of the cathode and hence greater plasma A u concentrations. Fragmentation of the HMDS molecule resulted in species such as CH, Fl, and Si which were detected by OES. Film deposition rate, as determined by optical interferometry, was found to be increased by the inclusion of Ar in the gas feed. Transmission electron microscopy revealed particles, probably of Au, embedded in the polymer films. Actinometric measurements of Au in the discharge and electron probe microscopy of the deposited material showed that film Au concentrations increase with increasing concentrations of Au in the plasma. A relatively low fragmentation of HMDS molecules in the de plasma was revealed by the very small Si-HIR absorption band which is usually prominent in spectra of plasma polymerized HMDS films.

Spectroscopic properties of Er3+ in oxysulfide glasses

Er3+ -containing gallium-lanthanum oxysulfide glasses have been prepared from Ga2O3 and La2S3 in a sulfur/argon reactive atmosphere. The samples have been characterized by absorption and emission spectroscopy and IR emission kinetics. Er3+ electronic transition intensities have been analyzed in the light of the Judd-Ofelt formalism, and quantum efficiencies evaluated for the Er3+ emission at 1.5 and 2.7 mum. The results so obtained suggest that these glasses display favorable properties concerning IR optical applications. (C) 2002 Elsevier B.V. B.V. All rights reserved.

FLUORINATED POLYMER-FILMS FROM RF PLASMAS CONTAINING BENZENE AND SULFUR HEXAFLUORINE

Mixtures of C6H6 and SF6 were polymerized in an r.f. discharge. Actinometry (quantitative optical emission spectroscopy) was used to determine trends in the plasma concentrations of the species F, H and CH as a function of the proportion of SF6 in the feed. Infrared spectroscopy and electron spectroscopy for chemical analysis were employed to characterize the deposited material. Increasing proportions of SF, in the feed produced increased fragmentation of the benzene molecules and greater fluorination of the deposited material. The deposition rate, as determined by optical interferometry, was found to be enhanced about 4 times by the presence of 10-20% SF6 in the feed. At 50% SF6 in the feed, deposition rates were greater than in pure C6H6 plasmas despite the (probably large) etching effect of atomic fluorine from the discharge. Relationships between the plasma composition, electron density and temperature, film composition and growth rate are discussed.

Thermogravimetry (TG) applied to the study of the reaction of mercury with platinum-rhodium alloy

Thermogravimetry (TG) energy dispersive X-ray microanalysis (EDX), scanning electron microscopy (SEM), mapping surface, X-ray diffraction (XRD), inductively coupled plasma emission spectroscopy and atomic spectroscopy with cold vapor generation have been used to study the reaction of mercury with platinum-rhodium (Pt-Rh) alloy. The results suggest that, the electrodeposited Hg film reacts with Pt-Rh to form intermetallic compounds of different stability, when heated indicated by at least four weight loss steps. Intermetallic compounds as PtHg4 and PtHg2 was characterized by XRD. These intermetallic compound are the main product presents on the surface of the samples after remotion of the bulk mercury via thermal desorption techniques. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Plasma enhanced chemical vapor deposition of titanium(IV) ethoxide-oxygen-helium mixtures

Thin films were deposited by plasma enhanced chemical vapor deposition from titanium (IV) ethoxide (TEOT)-oxygen-helium mixtures. Actinometric optical emission spectroscopy was used to obtain the relative plasma concentrations of the species H, CH, O and CO as a function of the percentage of oxygen in the feed, R(ox). The concentrations of these species rise with increasing R(ox) and tend to fall for R(ox) greater than about 45%. As revealed by a strong decline in the emission intensity of the actinometer Ar as R(ox) was increased, the electron mean energy or density (or both) decreased as greater proportions of oxygen were fed to the chamber. This must tend to reduce gas-phase fragmentation of the monomer by plasma electrons. As the TEOT flow rate was fixed, however, and since the species H and CH do not contain oxygen, the rise in their plasma concentrations with increasing R(ox) is explained only by intermediate reactions involving oxygen or oxygen-containing species. Transmission infrared (IRS) and X-ray photoelectron (XPS) spectroscopies were employed to investigate film structure and composition. The presence of CH(2), CH(3), C=C, C-O and C=O groups was revealed by IRS. In addition, the presence of C-O and C=O groups was confirmed by XPS, which also revealed titanium in the +4 valence state. The Ti content of the films, however, was found to be much less than that of the monomer material itself. (C) 2007 Elsevier B.V. All rights reserved.

Speciation of lead in seawater and river water by using Saccharomyces cerevisiae immobilized in agarose gel as a binding agent in the diffusive gradients in thin films technique

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)