Authors:Angela Martins, João M. Silva, Fernando Râmoa Ribeiro, and M. Filipa Ribeiro
it affects the location and size of metal particles and, consequently, the degree of proximity between the hydrogenating and acid sites. The second purpose of this study concerns the influence of rareearthelements La, Nd and Yb in bifunctional
Authors:Sanjukta Kumar, Shailaja Pandey, and Sangita Kumar
A method has been developed for the analysis of rare earth elements (REEs) in kimberlite samples using inductively coupled
plasma mass spectrometer (ICP-MS). The samples were dissolved using sodium peroxide fusion and after appropriate dilutions the solutions were analyzed
using ICP-MS. The paper presents the concentration of rare-earth elements as determined by ICP-MS in eight kimberlite samples
from Central India. The method was validated using certified reference materials STSD-1 and STSD-2 from Canadian Certified
Reference Material Project. The method detection limit of various REEs varies from 0.12 to 1.54 mg kg−1. The total REE concentrations range from 418 to 726 mg kg−1 and fall within the interval of those reported in the literature for kimberlites. Despite the marked difference in the REE
contents, all the analyzed samples show similar REE patterns that resemble those for kimberlites. In order to compare ICP-MS
results, the samples were analyzed using instrumental neutron activation analysis which is a reference method for determination
of REEs in geological samples.
Authors:Geraldo Capannesi, Alberto Rosada, Maurizio Manigrasso, and Pasquale Avino
In geochemistry, the distribution of the Rare Earth Elements (REEs) in earth crust and mantle allows to understand geochemical
cycles and origin and age of igneous rocks. In this article REEs (Ce, Dy, Eu, La, Nd, Sm, Tb, and Yb), Th and U in ores of
the North-Latium (Bracciano area, Ceriti Mt., Fate Mt., Sabatini Mt., Vulsini Mt., Acqua Rossa basin), have been investigated
for evaluating the extraction feasibility for industrial applications. 107 samples were irradiated in the rotating rack of
the TRIGA Mark II reactor of the R.C. Casaccia (ENEA) at neutron flux of 2.6 × 1012n × cm−2 × s−1 for 12 h together with primary and secondary standards. The gamma spectrometry measurements were performed after 8 h, 3 and
30 days of decay by means of HPGe detector (FWHM 1.75 keV at 1332.5 keV, peak/Compton ratio 55.1, relative efficiency of 22%)
connected to a multi-channel analyzer. The total REE mean content is 105 μg g−1, ranging widely between 2.23 and 410.5 μg g−1 (average coefficient of variation 112%). A similar behavior is found for Th and U: their average levels are 13.5 and 6.0 μg g−1, respectively. A quite good correlation between REEs and Th (and U) is found for Ceriti Mt. (r2 > 0.8) whereas for the other areas the correlation is <0.7. The results obtained evidence the low U content in the investigated
Authors:A. Silva, S. Almeida, M. Freitas, A. Marques, C. Ramos, and T. Pinheiro
Harbour activities such as loading, unloading and transport of materials may be an important source of Atmospheric Particulate
Matter (APM). Depending on the materials, the type of operation and the meteorological conditions, these activities may have
an impact on the levels of APM around harbour areas. The aim of this work was to characterize the emissions of dust providing
from operations associated with phosphorite handling in harbours. Phosphorite is a non-detrital sedimentary rock which contains
high amounts of phosphate bearing minerals and is used for the production of phosphorous based fertilizers. When handled in
harbours frequently cause visual and environment impacts due to its physical and chemical characteristics. The techniques
Instrumental Neutron Activation Analysis and Particle Induced X-ray Emission were applied as sensitive analytical tools for
the determination of heavy metals and rare earth elements in phosphorite and in the APM sampled in the harbour during the
unloading operations. Results showed that manipulation of phosphorite during harbour operations resulted in high emissions
of particles, principally from the coarse fraction. These emissions were enriched in rare earth elements and heavy metals
and were very affected by the provenience of the phosphorite.
Authors:Z. Rzączyńska, A. Kula, J. Sienkiewicz-Gromiuk, and A. Szybiak
obtain the soluble form of the ligand. Ammonium salt of the acid was added to an aqueous solution of lanthanide chloride while stirring. For the preparation of the complexes, the following oxides of rareearthelements were used: La 2 O 3 , Pr 6 O 11 , Nd
A sensitive radiochemical procedure has been developed for the separation and determination of Dy, Sm, Gd, Eu, La and Lu in high purity uranium. The method is based on quantitative extraction of uranium using NPy/benzene as an extractant from 7M HCl solution. Rare earth elements (REE) remaining in the aqueous phase were subsequently determined by INAA.
The paper describes the production of a tracer packet of heavier rare earth elements containing carrier-free radionuclides
of 153,155Tb, 153,155,157Dy, 159Ho, 159,161Er, 161Tm produced by medium energy 7Li and 12C irradiation on an europium oxide target and the subsequent separation of bulk europium from the carrier-free products.
Fresh and aged samples of foraminifera and red algae from two different climatic areas (the Great Barrier Reefs of Australia and the northwestern Mediterranean Sea) were analyzed by non-destructive thermal and epithermal neutron activation for some traces and rare-earth elements (REE). Mechanisms were tentatively proposed to explain the measured distributional differences: iron scavenging effect, microbial intervention at given stages of very early diagenesis, feeding behaviour of organisms... REE and traces follow increases of iron content during biodiagenesis; this process does not apparently originate discrimination in the distributional pattern of REE. Eu negative and Ce positive anomalies were recorded in both types of organisms; these anomalies were explained by bioprocesses.
Instrumental neutron activation analysis of eight geochemical standard materials has been carried-out and the concentration values of nine rare-earth elements (REE) (La, Ce, Nd, Sm, Eu, Gd, Tb, Yb and Lu) have been determined. Discussion of some problems in the determination of those elements is presented and the results obtained are compared with literature values. In general, good agreement with available data was obtained but discrepancies with concentration values for a number of elements in some of these standards are discussed.
Authors:N. Kremliakova, K. Barsukova, and B. Myasoedov
Behaviour of transplutonium and rare-earth elements on TVEX, containing TBP, HDEHP, mixture of TBPHDEHP (11), PAPNA and TOA has been studied. The analytical possibility of isolation and separation of tetravalent Pu and Bk from trivalent actinides and lanthanides from strong nitric acid solutions (1.0–12.0) on TVEX with TBP, POR, HDEHP and TOA has been demonstrated. The separation of trivalent Bk, Cf and Eu from Am and Cm is real on TVEX, containing HDEHP and mixture of TBPHDEHP.