E. Orvini

Rare earth elements determination in environmental matrices by INAA

The mobilization of rare earth elements (REEs) in the environment requires monitoring of these elements in environmental matrices, in which they are mainly present at trace levels. In nature, REEs are frequently associated to thorium and uranium, elements with a chemical behavior similar to that of lanthanides, as well as scandium. The similarity in REEs chemical behavior makes the separate determination of each element by chemical methods difficult; instrumental neutron activation analysis (INAA), based on nuclear properties of the elements to be determined, is a method of choice in trace analysis of REEs and related elements. The levels of REEs, U, Th, and Sc were determined in two environmental matrices which are being certified as Reference Materials: CRM 600-Calcareous Soil and CRM 667-Estuarine Sediment, issued by the EU Standards, Measurement and Testing Programme.

The Medical Mystery of Napoleon Bonaparte An Interdisciplinary Expose

Napoleon Bonaparte (1769 to 1821) is one of the most studied historical figures in European history. Not surprisingly, amongst the many mysteries still surrounding his person is the cause of his death, and particularly the suspicion that he was poisoned, continue to intrigue medical historians. After the defeat of the Napoleonic Army at the battle of Waterloo in 1815, Napoleon was exiled to the small island of Saint Helena in the South Atlantic, where he died 6 years later. Although his personal physician, Dr François Carlo Antommarchi, stated in his autopsy report that stomach cancer was the cause of death, this diagnosis was challenged in 1961 by the finding of an elevated arsenic concentration in one of Napoleons hair samples. At that time it was suggested that Napoleon had been poisoned by one of his companions in exile who was allegedly supported by the British Government. Since then Napoleons cause of death continues to be a topic of debate. The aim of this review is to use a multidisciplinary approach to provide a systematic and critical assessment of Napoleons cause of death.

Gallium distribution in several human brain areas

Gallium is an element of increasing biological interest: It is involved in problems related to environmental pollution (Ga compounds are used in electronics industry) and to clinical treatments (Ga radionuclides are employed to detect neoplastic lesions). Moreover, since its chemical behavior is similar to that of aluminum, gallium could play a role in the health effects attributed to this element.Data on naturally occurring Ga levels in human samples from healthy subjects are scanty; regarding the brain, the only reliable values available in the literature were published by Hamilton in 1972/73. In this work, the gallium distribution in several human brain areas, evaluated by radiochemical neutron activation analysis (RNAA), was found to be dishomogeneous. The element concentration determined in dry samples was, in any case, lower than the ppb level.

Determination of aluminum by neutron activation analysis in human lung tissue and in chemicals for dialysis of uremic patients

Aluminum (Al) determination in human lung tissue, in chemicals for dialysis fluids, and in commercially available dialysis solutions is carried out using both Instrumental and Radiochemical Neutron Activation Analysis (INAA and RNAA). For some matrices, pre-and post-irradiation Al separations are tested.Chelex 100 resin and HDEHP, this latter adsorbed both on teflon and polyurethane foam, are employed for the pre-irradiation Al separations.The postirradiation procedures are performed using roughly the same schemes; the conventional Al precipitation as hydroxide is also carried out.Al values found in lungs of workers exposed to Al containing dust appear to be much higher than those found for unexposed people. Chemicals analyzed seem pure enough to give suitable dialysis solutions; for commercially available dialysis fluids, a 10-fold reduction of Al content should be convenient.

Five years activity in determining trace elements for the certification of standard reference materials by neutron activation analysis

SummaryA review of the experiences developed in the last five years of analytical work concerning the determination of trace element concentrations in reference materials by neutron activation analysis has been reported and discussed. Several elements such as Co, Sc, Mn, V, Fe, La, Sb, Zn, Th, have been determined by instrumental neutron activation analysis, while elements such as Hg, Se, As, Cu, Cd, I, required a selective radiochemical procedure. The results obtained are compared with the final certified values. For each matrix and/or group of matrices analytical problems and their solutions are illustrated.ZusammenfassungEine Übersicht über die Erfahrungen der letzten 5 Jahre bei der analytischen Bestimmung von Spurenelementen mittels Neutronenaktivierung wurde gegeben und diskutiert. Einzelne Elemente wie Co, Sc, Mn, V, Fe, La, Sb, Zn und Th wurden mit Hilfe instrumenteller Neutronenaktivierungsanalyse bestimmt; andere Elemente, wie Hg, Se, As, Cu, Cd und J, erfordern ein selektives radiochemisches Verfahren. Die erhaltenen Ergebnisse wurden mit sichergestellten Werten verglichen. Für jede Matrix bzw. Matrixgruppe wurden die analytischen Probleme und deren Lösung angegeben.

LEACHABILITY STUDY FOR SOME HEAVY METALS FROM URBAN SOLID WASTE INCINERATORS BOTTOM ASH

ABSTRACT A first approach to the leachability behaviour of some heavy metals (Cd, Cu, Ni, Pb) from urban solid waste incinerators Bottom Ash is presented. Leachability experiments were performed in batch with distilled water, at different extraction times. pH Variations during the leaching tests were also investigated. The concentrations of heavy metals in the leachates were determined by atomic absorption spectrophotometry, using the flameless atomization technique. The results show a potential contribution of municipal incinerators to the release of heavy metals in surface waters. A comparison between the leachability behaviour of BCR Standard Reference Material n. 38 Coal Fly Ash and incinerators Bottom Ash is presented and discussed. KEYWORDS: Urban solid wastes; municipal incinerators; leachability; Bottom Ash; Coal Fly Ash; ash pond water; atomic absorption spectrophotometry; flameless technique.