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Abstract  

The atmospheric particulate of industrialized cities had become a mixture of potentially toxic substances whose concentrations must be monitored to assess the pollution levels. Trace metals and elements are part of these pollutants and the knowledge of their total concentration in the air as well as their distribution in the different aerosol particle sizes is necessary to evaluate the pollution risk in terms of maximum present levels and long term exposure. In the present work, a preliminary part of a study initiated for monitoring the trace element levels present in the atmospheric particulate of the city of Milan (north Italy) and of its suburban areas is presented. More than 25 elements have been determined in Milan downtown along a period of three years and in different weather conditions. The granulometric distribution of selected potentially toxic elements (such as vanadium, lead, cadmium, nickel) has been also determined to evaluate their concentrations in different inhalable fractions (alveolar and bronchial — tracheal). Instrumental Neutron Activation Analysis (INAA) has been used for the determination of the great part of the elements while Graphite Furnace Atomic Absorption Spectroscopy (GF-AAS) has been employed for the determination of lead and, in some cases, for nickel, cadmium and copper.

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Abstract  

Two new simple methods were studied for the analysis of radium in fresh waters by concentration and purification. Both methods are based on the use of an inorganic selective adsorber, namely basic lead rhodizonate, LERHO, and partially reduced tin dioxide (PRTD). The procedures were checked by using filtered fresh waters spiked with 0.1 Bq of226Ra, and in the presence of few μg/l of barium. In each experiment133Ba radioisotope was added to water samples to measure the yield of the overall procedure by γ-counting. Barium and radium were adsorbed from basic solutions on LERHO packed chromatographic column in the first procedure, while batch experiments were preferred for the adsorption on PRTD. After separation,226Ra and barium were eluted from the exchangers and co-precipitated onto small filters as thin film, supported on an inactive barium sulphate substrate, to be submitted to alpha-and gamma-spectrometry. Both methods gave promising results.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
M. Ganzerli-Valentini
,
S. Meloni
,
V. Caramella-Crespi
, and
P. Borroni

Abstract  

The adsorption of about 50 ions on molybdenum dibromide, (Mo6Br8)Br4·2H2O, in nitric acid was investigated. The preparation of the adsorber and its characterization is presented and discussed. Adsorption mechanism studies were carried out for some noble metals and chromium. Sorption cannot be ascribed to ion exchange mechanism but to formation of insoluble species, and to settlement of few ions into surface sorption sites or into a limited number of cavities in the cluster crystal structure of the adsorber.

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Abstract  

Copper, iridium, platinum and gold content was determined in 15 italian chondritic meteorites by destructive neutron activation analysis. The chemical procedure involves few steps: sample dissolution, group separation of noble metals on inorganic adsorbers and gamma-ray spectrometry. Element content and atomic abundances (Si=106 atoms) are presented and discussed. Precision and accuracy of the analytical method are given as well. Copper, platinum and gold content is within the reported ranges for ordinary chondrites, whereas the iridium content is located on the low side of reported values.

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