15 research outputs found

    Two New Reference Materials Based on Tobacco Leaves: Certification for over a Dozen of Toxic and Essential Elements

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    The preparation, certification, and characterization of two new biological certified reference materials for inorganic trace analysis have been presented. They are based on two different varieties of tobacco leaves, namely, Oriental Basma Tobacco Leaves (INCT-OBTL-5), grown in Greece, and Polish Virginia Tobacco Leaves (INCT-PVTL-6), grown in Poland. Certification of the materials was based on the statistical evaluation of results obtained in a worldwide interlaboratory comparison, in which 87 laboratories from 18 countries participated, providing 2568 laboratory averages on nearly 80 elements. It was possible to establish the certified values of concentration for many elements in the new materials, that is, 37 in INCT-OBTL-5 and 36 in INCT-PVTL-6, including several toxic ones like As, Cd, Hg, Pb, and so forth. The share and the role of instrumental analytical techniques used in the process of certification of the new CRMs are discussed

    2013, 5−11 Physicochemical Problems of Mineral Processing

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    Abstract: Biotechnology is an effective and environmental friendly method of waste utilization and poor refractory ores exploitation, well known since 1949 and successfully developed in many countries: Spain, Bulgaria, USA, and Sweden. Biotechnology opens the possibility to obtain uranium as by-product in rare element recovery process (eg. Co, Au, Re, Rh, Pt) and positively affects the economic efficiency of technology. The research program of biological exploitation of waste and poor ores in Poland is presented. Microbial consortia able to oxidize iron under neutral and acidic conditions (Fe concentration in ore is 1.8-3.4%) are isolated and developed during project realization

    Silver nanoparticle accumulation by aquatic organisms – neutron activation as a tool for the environmental fate of nanoparticles tracing

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    Water environments are noted as being some of the most exposed to the influence of toxic nanoparticles (NPs). Therefore, there is a growing need for the investigation of the accumulation and toxicity of NPs to aquatic organisms. In our studies neutron activation followed by gamma spectrometry and liquid scintillation counting were used for studying the accumulation of silver nanoparticles (AgNPs) by freshwater larvae of Chironomus and fish Danio rerio. The influence of exposition time, concentration and the source of nanoparticles on the efficiency of AgNP accumulation were studied. It was found that AgNPs are efficiently accumulated by Chironomid larvae for the first 30 hours of exposition; then, the amount of silver nanoparticles decreases. The silver content in larvae increases together with the NP concentration in water. Larvae which have accumulated AgNPs can be a source of nanoparticles for fish and certainly higher levels of Ag in the trophic chain. In comparison with water contamination, silver nanoparticles are more efficiently accumulated if fish are fed with AgNP-contaminated food. Finally, it was concluded that the applied study strategy, including neutron activation of nanoparticles, is very useful technique for tracing the uptake and accumulation of NPs in organism

    Two new separation schemes for the group isolation of rare earth elements (REE) from biological and other matrices and their determination by ICP-MS, NAA and chromatographic methods

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    Two new group separation schemes, based on ion exchange chromatography, for the selective and quantitative isolation of rare earth elements (REE) from accompanying elements, were devised. After checking their performance with the aid of radioactive tracers, the schemes were further used together with ICP-MS, NAA and ion exchange chromatography for the determination of Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu in two certified reference materials (CRMs). The results were compared with another series of analyses, where the REEs were determined directly, i.e. without pre-separation, by instrumental neutron activation analysis (INAA) and inductively coupled plasma mass spectrometry (ICP-MS). It was demonstrated that while direct INAA and ICP-MS in most instances provide reliable results for the majority of REEs, for some elements, notably Sc, Yb and Tm in the cases of ICP-MS and INAA, respectively, systematic errors occur or may potentially occur
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