Concentração de íons flúor em águas minerais envasadas no Rio Grande do Sul / Concentration of fluoride ions in mineral water bottled in the state of Rio Grande do Sul

Objetivo: avaliar o nível de flúor presente nas águas minerais carbogasosas e não carbogasosas envasadas no estado do Rio Grande do Sul, comparando os dados com as informações descritas nos rótulos das embalagens. Materiais e método: foram analisadas cinco marcas comerciais de água mineral. Os valores de padrão/ amostra e tampão Tisab foram utilizados em uma relação de 1:1, e as amostras foram lidas em duplicata. As amostras carbogasosas foram agitadas com bastão magnético para eliminação do gás carbônico. Para determinação de flúor, foram utilizados analisador específico de íons, eletrodo seletivo para íon flúor, eletrodo de referência Ag/AgCl de junção simples. Resultados: foram encontradas concentrações de flúor variando entre 0,13 mg F-/L e 1,31 mg F-/L, com diferenças entre os valores estipulados nos rótulos das marcas de água mineral avaliadas e as análises laboratoriais na presente investigação. Os valores de duas marcas de água mineral com flúor analisadas no estudo mostraram-se acima, considerando os valores de referência (0,6-0,8 mg F-/L), e uma marca não apresentou valores de ação preventiva contra a cárie dentária (valores abaixo de 0,6 mg F-/ L). Conclusão: conclui-se que há divergência entre os valores de íons flúor encontrados nas medições e os informados nos rótulos, sendo necessário um sistema de melhor vigilância para o controle dos níveis de flúor nas águas minerais disponibilizadas à população do estado do Rio Grande do Sul, considerando os benefícios do consumo de águas minerais para prevenção dos níveis de cárie na população. (AU)

Objective: quantify the fluoride level in carbogaseous and non-carbogaseous mineral waters bottled in the state of Rio Grande do Sul, Brazil, as well as to compare the data with the information described on the package labels. Materials and method: five brands of mineral water were analyzed. Standard/sample values and Tisab buffer were used in a ratio of 1:1, and the samples were read in duplicates. The carbogaseous samples were shaken with a magnetic rod to eliminate the carbon dioxide. For fluoride determination, a specific ion analyzer was used, as well as a fluoride ion-selective electrode, single-junction Ag/AgCl reference electrode. Results: fluoride concentrations ranging from 0.13 mg F-/L to 1.31 mg F-/L were found, with differences between the values specified in the labels of the mineral water brands evaluated and the laboratory analyses of the present investigation. The values of two brands of mineral water with fluoride analyzed in the study were high, considering the reference values (0.6-0.8 mg F-/L), and one brand did not present values of preventive action against dental caries (below 0.6 mg F-/L). Conclusion: there is a divergence between the values of fluoride ions measured and those reported on the labels, which requires a better surveillance system for controlling fluoride levels in the mineral waters offered to the population of the state of Rio Grande do Sul, Brazil, considering the benefits of mineral water consumption to prevent caries levels in the population. (AU)

A study on inorganic elements in psammomas from ovarian & thyroid cancer.

Background & objectives: Concentric lamellar calcifications known as psammoma bodies (PB) are found in benign and malignant tumours. Whether or not the inorganic element concentrations in psammomas are similar to serous adenocarcinoma of the ovary and thyroid papillary cancer tissues has not yet been ascertained. We undertook this retrospective study to establish if there is any difference in the concentrations of inorganic ions found in psammomas in serous adenocarcinoma of the ovary, and those found in thyroid papillary cancer tissue. Methods: PB samples from patients with adenocarcinoma of the ovary (n = 10) and with thyroid papillary cancer (n = 10) were analyzed through inductively-coupled plasma spectroscopy (ICP). Results: There were no significant differences in the concentrations of inorganic elements in PB from thyroid papillary cancer than in those PB from ovarian cancer. Interpretation & conclusions: Differences in the concentrations of inorganic elements may be due to the variation in environmental pollution. Our study had limitation of small sample size. Our results suggest that some inorganic elements can participate in the origin of psammoma bodies.

The exploration of the antibacterial mechanism of fe3+ against bacteria

This study demonstrated that the bacteria could adsorb Fe3+ and reduce Fe3+ to Fe2+. Iron had significant bacteriostatic effects, which were directly proportional to the iron concentration and under the influence of pH and chelator. It presumed that the inhibition of Fe3+ acts through the formation of hydroxyl free radicals.

The interaction of polyacid-modified composite resins ("compomers") with aqueous fluoride solutions

OBJECTIVE : The aim of this study was to investigate how the release of fluoride from two compomers and a fluoridated composite resin was affected by exposure to KF solution. MATERIAL AND METHODS: Two compomers (Dyract AP and Compoglass F) and one fluoridated composite (Wave) were prepared as discs (6 mm diameter and 2 mm thick), curing with a standard dental lamp. They were then stored in either water or 0.5% KF for 1 week, followed by placement in water for periods of 1 week up to 5 weeks total. Fluoride was determined with and without TISAB (to allow complexed and decomplexed fluoride to be determined), and other ion release (Na, Ca, Al, Si, P) was determined by ICP-OES. RESULTS: Specimens were found not to take up fluoride from 100 ppm KF solution in 24 h, but to release additional fluoride when stored for up to five weeks. Compomers released more fluoride cumulatively following exposure to KF solution (p<0.001), all of which was decomplexed, though initial (1 week) values were not statistically significant for Dyract AP. Other ions showed no variations in release over 1 week, regardless of whether the specimens were exposed to KF. Unlike the compomers, Wave showed no change in fluoride release as a result of exposure to KF. CONCLUSIONS: Compomers are affected by KF solution, and release more fluoride (but not other ions) after exposure than if stored in water.

Estudio del dimeltilsulfxido (DMSO) y del Ion Amonio (NH+4) en sistemas zeoliticos por medio de las espectroscopias de masas, infrarrojo, resonancia paramagnetica electrónica y resonancia magnetica nuclear de pulsos / Study of the dimethyl sufoxide de (CDMSO) and the ammonia ions (NHT4) in zeolites systems by means to mass spectroscopy electronic paramagnetic resonance and paramagnetic pulse nuclear resonance

Fueron revisados los resultados de las investigaciones realizadas en las zeolitas, por medio de la espectroscopia de infrarrojo y las técnicas de análisis térmico diferencial y flashdesorption siendo imposible determinar la ubicación del ión amonio. El uso de la espectrometría de masa, hizo posible determinar el número de sitios de ubic ción del ión amonio en la red zeolitica y el tipo de acoplamiento con moléculas de agua y con la red. La espectroscopia de infrarrojo nos permitió separar las bandas de absorción debidas a las vibraciones del ión amonio perturbado por su contorno a la red zeolítica hidratada. De los resultados obtenidos por espectrometria de masas y espectroscopia de infrarrojo se concluyó que las muestras usadas, intercambiadas por iones amonio en medio acuoso, no son adecuadas para resonancia magnetica nuclear, dada la imposibilidad de deshidratar la muestra sin deamuzarla