RESUMO
A magnetic metal organic framework (MMOF) was synthesized and used to separate Sr2+ in aqueous solution. The shape and structure of prepared Fe3O4@UiO-66-NH2 were characterized, and the absorbed concentration of strontium was determined through inductively coupled plasma mass spectrometry. The results indicated that Fe3O4 and UiO-66-NH2 combined through chemical bonding. The experimental adsorption results for separation of Sr2+ in aqueous solution indicated that the adsorption of Sr2+ to Fe3O4@UiO-66-NH2 increased drastically from pH 11 to pH 13. The adsorption isotherm model indicated that the adsorption of Sr2+ conformed to the Freundlich isotherm model (R2 = 0.9919). The MMOF thus inherited the superior qualities of magnetic composites and metal organic frameworks, and can easily be separated under an external magnetic field. This MMOF thus has potential applications as a magnetic adsorbent for low level radionuclide 90Sr.
Assuntos
Adsorção , Óxido Ferroso-Férrico , Química , Concentração de Íons de Hidrogênio , Estruturas Metalorgânicas , Química , Modelos Teóricos , Nanopartículas , Química , Estrôncio , Propriedades de Superfície , Poluentes Radioativos da Água , Purificação da Água , MétodosRESUMO
Nuts have received increased attention from the public in recent years as important sources of some essential elements, and information on the levels of elements in edible nuts is useful to consumers. Determination of the elemental distributions in nuts is not only necessary in evaluating the total dietary intake of the essential elements, but also useful in detecting heavy metal contamination in food. The aim of this study was to determine the mineral contents in edible nuts, and to assess the food safety of nuts in the Beijing market. Levels of Li, Cr, Mn, Co, Cu, Zn, As, Se, Rb, Sr, Mo, Cd, Cs, Ba, Pb, Th, and U in 11 types of edible nuts and seeds (macadamia nuts, lotus nuts, pistachios, sunflower seeds, pine nuts, almonds, walnuts, chestnuts, hazelnuts, cashews, and ginkgo nuts) as well as raisins were determined by inductively coupled plasma mass spectrometry (ICP-MS). The accuracy of the method was validated using standard reference materials GBW10014 (cabbage) and GBW10016 (tea). Our results provide useful information for evaluating the levels of trace elements in edible nuts in the Beijing market, will be helpful for improving food safety, and will aid in better protecting consumer interests.
Assuntos
China , Análise de Alimentos , Métodos , Inocuidade dos Alimentos , Espectrometria de Massas , Nozes , Química , OligoelementosRESUMO
<p><b>OBJECTIVE</b>To construct a high performance open source software engine based on IBM SPLASH algorithm for later research on pattern discovery.</p><p><b>METHODS</b>Gpat, which is based on SPLASH algorithm, was developed by using open source software.</p><p><b>RESULTS</b>GNU Pattern (Gpat) software was developped, which efficiently implemented the core part of SPLASH algorithm. Full source code of Gpat was also available for other researchers to modify the program under the GNU license.</p><p><b>CONCLUSION</b>Gpat is a successful implementation of SPLASH algorithm and can be used as a basic framework for later research on pattern recognition in biological sequences.</p>