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- Author or Editor: M. Gallorini x
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Abstract
The following elements: Cr, Zn, Co, Cd, Mn, V are determined in a sample of NBS (spinach) which has to be certified as a new standard. Both neutron activation analysis and atomic absorption spectrometry are used; a good agreement is foudn among the different techniques. Different procedures of samples chemical dissolution are compared.
Abstract
High specific activity radiotracers, used in studies related to trace elements and human health, must be characterized by the following specific requirements: (i) high specific activity (activity/mass of isotopic carrier), (ii) high activity concentration (activity/volume or mass of substrate), (iii) radionuclidic, radiochemical and chemical purities, (iv) biological compatibility (physiological pH, sterility and physiological values). For this purpose, selective radiochemical separations and quality control procedures have been developed and tested at our laboratories for the production of several NCA radiotracers.
Abstract
A pyrolysis-neutron activation analysis (NAA) procedure has been developed and applied to the speciation of arsenic in solid biological samples. The method involves the retention of the inorganic arsenic in the pyrolysis boat by the addition of NaOH, the volatilization and trapping of the organic arsenic on a cation exchange resin and the subsequent NAA of the resin for the determination of the trapped arsenic. The method, developed with the aid of radiochemically labelled arsenic compounds, has been applied to the determination of the ratio of inorganic to organic arsenic species in commercical shrimps as well as in NBS standard reference materials such as oysters and orchard leaves. The results show different relative amounts of inorganic arsenic content in the samples analysed. In the shrings the fraction of inorganic arsenic was of the order of 20%, in the oysters the inorganic arsenic consfituted 60% of the total arsenic concentration while in the samples of vegetable origin more than 98% of the arsenic was of inorganic nature.
Abstract
Neuromelanin (NM) is an ubiquitary intraneuronal pigment in human brain and its abundance is probably related to neuronal vulnerability, especially in Parkinson Disease. In this and other neurodegenerative diseases an association was shown with endogenous accumulation and environmental exposure to metals. Melanins are strong metal chelators, therefore it is important to measure their content in brain regions and in their NMs. In this work the concentration of 18 elements was measured in each brain region and in the corresponding NM by instrumental neutron activation analysis.
Abstract
No-carrier-added48V at 37 Mbq (mCi) levels was produced at the JRC-Ispra cyclotron by (
, n) reactions on a scandium target and used to label environmental and physiological levels of vanadium for metallobiochemical investigations. The radiochemical separation of48V from Sc is very simple and rapid and involves a single chromatographic step after fast dissolution of the bombarded target. The yield of the separation and the radioisotopic purity of the separated48V were nearly 100% A summary of the main results concerning different metabolic investigations on rats including absorption, retention, transfer of48V from mothers to newborns, binding with enzymes as well as uptake by cell culture system is reported.
Abstract
The use of radiotracers with high specific activity in research on health impact of trace metals overcomes many of the analytical difficulties associated with experimentation carried out at metal levels which are typical of the polluted environment. It allows one to detect and measure ultratrace amounts of metals in biological samples and to follow them into different biochemical compartments, such as subcellular fractions and molecular components. This work shows typical examples of metallotoxicological studies carried out at the JRC-Ispra using radioisotopes with high specific radiactivity produced in the nuclear reactor and in the cyclotron. Applications refer to the use of45Ti,48V,64Cu,95Nb and106mAg in in-vivo and in-vitro studies related to environmental and occupational toxicology research on trace metals.
Abstract
The increasing concentration of Pt, Pd and Rh in the environment is mainly due to the release of these elements from the catalytic converters of the motorvehicles. This situation makes it necessary to carry out metallotoxicological experiments on both cell cultures and laboratory animals, in order to assess their impact on living organisms after a Long Term and Low Level Exposure (LLE). Both nuclear reactionsnatIr(p,xn) andnatOs(α,xn) were investigated in the energy range up to 45 MeV for protons and 38 MeV for alpha-particles, in order to optimize the irradiation parameters for the production of188,189,191Pt. Several sets of thin- and thick-target excitation functions were determined experimentally by cyclotron irradiation at both Milano and Ispra cyclotrons. This paper reports the irradiation parameters studied and adopted and two radiochemical procedures for the separation of radio-Pt from an Os target, as well as from ruthenium, iridium and gold impurities. These procedures were used to obtain very high specific activity Pt radionuclides in No Carrier Added (NCA) form. Radionuclidic, radiochemical and chemical purity measurements were carred out by the use of several techniques like ψ-spectrometry, ion-exchange radio-chromatography, atomic absorption spectrometry and neutron activation analysis.
Summary
Scarce information is available on the content of metals and their molecules in the human brain. Iron, copper and other metals are involved in neurodegenerative disorders like Parkinson’s Disease (PD), however, their behavior in physiological conditions is poorly understood. In this study we have measured iron, copper and their major proteins (ferritins and ceruloplasmin) in substantia nigra (SN) of normal subjects at different ages, since this is the main target region of PD. An increasing trend for iron and copper concentration was found in aging. Ferritins were also increasing in aging while ceruloplasmin did not vary. These data show that the accumulation of these metals requires an increased expression of storage molecules to prevent toxic effects of iron and copper.
Summary
An instrumentation and a method have been developed to investigate the growth of plant roots by injection of 75Se radioactive isotope in the stem base. Since the isotope is transferred into the active root, it is possible to investigate where the growth occurs in the soil profile. The distribution of radioactivity in the root system is measured by means of an automatic detection equipment controlled by a portable PC. The design of the detection probe is discussed and its field use is surveyed. The whole instrumentation is compact and can easily be used to study the effects of irrigation and fertilization on crops growing under field conditions. The results obtained in the field tests show how the levels of nutrients and moisture influence the root development.
Abstract
High Specific Activity Radio-Nuclides (HSARN) are a powerful tool to label a large range of chemical species at very low concentration levels. In order to obtain these radiotracers in a very high specific activity form, it is necessary to optimize the production methods, to separate and purify them from the irradiated target without the addition of inactive carrier, to carry out a series of analytical and radioanalytical tests to determine their 
true
specific activity and to verify a series of purity parameters. A review of irradiation methods and nuclear parameters adopted in our laboratories for the preparation of some tens of radiotracers are presented.
