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1.
Research activity in the Balkan and East Mediterranean countries was evaluated on the basis of publications appearing in Analytical Abstracts (AA) during the cumulative 8-year period of 1994-2001. This was accomplished by assessing the scientific publication productivity in analytical chemistry as the number of publications from each country and the number of publications per population unit. To assess the impact in the scientific community, the mean impact factor for each country was calculated. The publication productivity trend was recorded for the 7-year period 1994-2000. Moreover, the preference to publish in specific journals per country was appraised. According to the total number of publications, Egypt (765 publications) and Greece (717 publications) are the most productive countries, while Slovenia shows the highest number of publications per million of population (140). Scientists from Israel published their work in the highest impact analytical journals with a mean impact factor of 2.02, followed by Slovenia (mean impact factor of 1.67) and Greece (mean impact factor of 1.53). Studies of scientists from different countries do not show any obvious preference to a single specific journal. It is interesting to note that preference for journals reveals the research interests of scientists from each country for sub-fields of analytical chemistry.  相似文献   

2.
Liquid chromatography (LC) was used for the fractionation of particular anthocyanins in glycoside form from methanol extracts of red grape skins and solid phase extracts of red wine. By the combination of nuclear magnetic resonance spectroscopy and LC-mass spectroscopy the identification of 13 anthocyanins in a particular LC fraction and hence the in particular peaks in chromatograms were obtained. Peaks areas in the chromatograms obtained under the semi-quantitaive conditions of the solid phase extracts of red wines Pinot Noir, Cabernet Sauvignon and Merlot from the Coastal wine-growing region in Slovenia, produced in 1999, were used as input data in chemometric analysis. The chemometric methods used were hierarchical clustering analysis and regularised discriminant analysis. The results of both methods give 100% correct classification of wines regarding the vine variety.  相似文献   

3.
Activity concentrations of 40K and 3H in drinking water from four sources in the vicinity of NPP Kr?ko and their correlation with geological data are presented. The data extends from the year 1996 until present. In addition, activity concentrations of 40K in drinking water at randomly selected sources in Slovenia are presented on a map. These activity concentrations vary by more than an order of magnitude with the largest values in northeastern part of the country.  相似文献   

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5.
George de Hevesy known as discoverer of hafnium, founder of radioanalytical chemistry and X-ray fluorescence analysis and father of nuclear medicine has done important research work in inorganic, physical and radioanalytical and physiological chemistry as well as in geochemistry, radiation biology and medicine. When he must flee for political reasons from a country he must change his colleagues, his equipments, and the topic of his work. It is extremely surprising that he could receive important results under such circumstances even at an advanced age.  相似文献   

6.
Besides their role as an external quality control tool, PT results or samples could be used as an alternative to fulfil some of the quality assurance requirements such as analytical precision, uncertainty assessment, and internal quality control. This additional use of proficiency testing could help laboratories to reduce the financial impact of their quality assurance process. The purpose of this paper is to highlight some practical uses of PT results or samples in the environmental analytical field, which have been implemented at ISSeP (Institut Scientifique de Service Public), either for method validation or for internal quality control.Presented at the Eurachem PT Workshop September 2005, Portorož, Slovenia  相似文献   

7.
129I is important as an environmental tracer of the biogeochemical cycling of iodine and of the dissemination of nuclear pollution, because anthropogenic 129I has been released from only few point sources and with its short mixing time its distribution therefore reveals the movement of 129I in the environment. A radiochemical neutron activation analysis method was developed to measure the concentration of 129I in soil samples. A procedure to pre-concentrate iodine from up to 150?g of soil was developed and validated using IAEA standard reference material IAEA-375 (Chernobyl soil). The method was applied to determine 129I/127I isotopic ratios as well as 129I and 127I concentrations in soils from several locations in Ukraine collected in 2006, 1996, 1993 and 1989, and from Slovenia, collected at various places in 2009 and 2006. The 127I concentrations in surface soils from Ukraine were in the range 2.3–23.1?µg?g?1 and for 129I (11.1–245.7)?·?10?8?µg?g?1 dry matter with the highest value of 1.47?·?10?3?µg?g?1 found in a soil sample collected in Yaniv, Ukraine in July 1993. In soil samples from Slovenia 127I concentrations ranged 0.73–130?µg?g?1 and 129I (8.0–245.7)?·?10?8?µg?g?1. The 129I/127I isotopic ratios of surface soils from Ukraine were in the range of the order of 10?9–10?5 and of 10?10–10?8 for soils from Slovenia. The highest isotopic ratio 13.6?·?10?5 was found in a soil sample collected in Yaniv, Ukraine in July 1993.  相似文献   

8.
Consumption of non-steroidal anti-inflammatory drugs (NSAIDs) is increasing and with it the danger of environmental pollution by pharmaceutical residues. Publications regarding NSAIDs in the environment not only show that they are toxic to many animal species, but also highlight the need for robust analytical methods for monitoring the level of such contaminants in environmental matrices. In our study we selected the four most widely used NSAIDs in Slovenia and Central Europe, ibuprofen, naproxen, ketoprofen and diclofenac, and studied their extraction from sediment samples. We examined several extraction techniques (ultrasonic extraction, Soxhlet extraction, pressurized liquid extraction, supercritical fluid extraction and microwave-assisted extraction) using a spiked sediment sample and determined optimal extraction conditions. After extraction we applied a clean-up step, derivatisation of the analytes and gas chromatography with mass spectrometric detection (GC-MSD) and selected the most appropriate extraction procedure. The optimised analytical method chosen for analysis of sediment samples consisted of microwave-assisted extraction, clean-up of the extract with SPE, derivatisation with MSTFA and determination with GC-MSD. The optimised procedure was applied to the analysis of two environmental river samples taken from the vicinity of Novo mesto, the biggest town in the south eastern part of Slovenia with 62,000 inhabitants, a hospital and a pharmaceutical factory in its vicinity. While analysis of the sample taken upstream of the town showed no detectable amounts of NSAIDs, analysis of samples taken downstream showed quantifiable levels of two of the studied NSAIDs (naproxen and ketoprofen). Besides these two NSAIDs, river water samples sampled at the same time and location on the River Krka also showed the presence of diclofenac. Sampling on the River Krka and other Slovene rivers will in the future be repeated at different sampling points in order to track down the main sources of pollution.  相似文献   

9.
Instrumental neutron activation analysis (INAA) for traces and major elements of several geological samples from “Zgounder” region in Morocco was performed utilizing the k 0-standardization method. Sample irradiation has been done by the 250 kW Triga Mark II reactor at Jozef Stefan Institute in Slovenia. Due to its accuracy, sensitivity and specificity, the k 0-standardization method is the most suitable method for non-destructive multielement analysis mainly for trace elements in rocks. It requires an accurate knowledge of the parameters of the irradiation facilities and other instrumentation parameters. It is an absolute standardization method, where the absolute nuclear data are replaced by a nuclear constant, the k 0-factor, determined experimentally with high accuracy. More than 40 elements were determined using about 30-second short and about 7-hour long irradiations. Gamma-rays emitted from the irradiated samples have been determined by a high purity germanium detector. Accuracy was assessed using the standard reference material AGV-1. This was less than 1% for major elements and about 5% for traces. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

10.
It is demonstrated for a spin-free, nonrelativistic, complete molecular Hamiltonian that there is an optimal solution to the separation of electronic and nuclear motions. The adiabatic approximation is obtained as a special limiting case. A fruitful interpretation of intermolecular correlation results from the assumption that such correlation involves the degeneracy of a molecular-energy state of one molecule with that of another chemical species, e.g., cubane and cyclooctatetraene. As a consequence, rigorous relationships are established for the influence of nodal patterns of the electronic functions on intermolecular correlation. Also derived are stringent symmetry rules which both electronic and nuclear functions involved in the correlation must obey. Throughout the treatment is a many-electron one.  相似文献   

11.
Nuclear forensic (NF) techniques are critical in responding to both environmental releases of nuclear materials and illicit trafficking activities involving both nuclear and counterfeit materials. Despite rising need, however, significant barriers exist to the future success of such research. This subset of analytical chemistry contains unique concerns (e.g. chronometry and impurity signatures), a wide variety of preparatory/instrumental approaches, and is in need of innovative solutions to current problems both in and out of the lab. The present work introduces existing NF research, development challenges and notes potential areas for advancement by highlighting several key analytical approaches. Examples of concerns and techniques discussed in this review include: chronometry, reference materials, separations, counting spectrometry, mass spectrometry and more.  相似文献   

12.
The closing of the nuclear fuel cycle is an unsolved problem of great importance. Separating radionuclides produced in a nuclear reactor is useful both for the storage of nuclear waste and for recycling of nuclear fuel. These separations can be performed by designing appropriate chelation chemistries and liquid-liquid extraction schemes, such as in the TALSPEAK process (Trivalent Actinide-Lanthanide Separation by Phosphorus reagent Extraction from Aqueous Komplexes). However, there are no approved methods for the industrial scale reprocessing of civilian nuclear fuel in the United States. One bottleneck in the design of next-generation solvent extraction-based nuclear fuel reprocessing schemes is a lack of interfacial mass transfer rate constants obtained under well-controlled conditions for lanthanide and actinide ligand complexes; such rate constants are a prerequisite for mechanistic understanding of the extraction chemistries involved and are of great assistance in the design of new chemistries. In addition, rate constants obtained under conditions of known interfacial area have immediate, practical utility in models required for the scaling-up of laboratory-scale demonstrations to industrial-scale solutions. Existing experimental techniques for determining these rate constants suffer from two key drawbacks: either slow mixing or unknown interfacial area. The volume of waste produced by traditional methods is an additional, practical concern in experiments involving radioactive elements, both from disposal cost and experimenter safety standpoints. In this paper, we test a plug-based microfluidic system that uses flowing plugs (droplets) in microfluidic channels to determine absolute interfacial mass transfer rate constants under conditions of both rapid mixing and controlled interfacial area. We utilize this system to determine, for the first time, the rate constants for interfacial transfer of all lanthanides, minus promethium, plus yttrium, under TALSPEAK process conditions, as a first step toward testing the molecular mechanism of this separation process.  相似文献   

13.
Following several national surveys that clearly indicated both a paucity of universities offering nuclear chemistry courses, and a severe shortage of personnel trained and educated in nuclear sciences, the US Department of Energy (DOE) agreed to fund a special summer program. This program would take 12 undergraduates on a competitive scholarship basis from across the nation, and provide them with an intensive 6 week course in the fundamentals of nuclear science. The first such course was taught in the summer of 1984 at San Jose State University in California, and has met each summer since that time. In this course, the students cover material equivalent to approximately 2 semester units of health physics and radiological safety, 3 semester units of lecture material on nuclear chemistry, radiochemistry, uses of radionuclides, and nuclear instrumentation, and 3 semester units of laboratory work in radiochemistry, radiation chemistry, and associated topics in nuclear science. A second course was opened in 1989, with the same curriculum and intent, and sited at the Brookhaven National Laboratory on Long Island, New York. With regard to intent, both courses are very successful, with a majority of persons going on to complete graduate degrees in some aspect of nuclear science (nuclear chemistry, nuclear physics, health physics, nuclear medicine PhD programs, and synthesis with radio-nuclides or programs such as nuclear pharmacy or pharmacology) or nuclear medicine and oncology via MD programs.Presently a member of the Chemistry Department, formerly Chairman of the Department of Chemistry, and now Dean of the College of Science at SJSU.  相似文献   

14.
Metallic Li in carbonaceous nanostructures was obtained in high concentration (as much as 33.4%) through metalorganic chemical vapor deposition involving certain lithium–aminoalkyl moieties, which are formed in situ , by decomposition of a precursor containing both cobalt and lithium. The bimetallic complex containing both lithium and cobalt was characterized by IR spectroscopy, mass spectroscopy, nuclear magnetic resonance spectroscopy, elemental analysis and thermogravimetric analysis. X‐ray photoelectron spectroscopy measurements performed on the as‐grown films demonstrate that lithium can be stable in metallic form in such a film. Results of X‐ray photoelectron spectroscopic analysis of the as‐grown films are presented as direct evidence of the formation and stabilization of metallic lithium in carbon nanotubes. Carbon nanotubes, encapsulating metallic lithium, can potentially act as a miniaturized nanobattery. Such a battery would be potentially useful in the next generation of communication and remote sensing devices, where a pulse of current is required for their operation. In addition, with metallic lithium, having an effective nuclear magnetic moment, such materials can be envisioned to show potential applications in devices based on nuclear magnetic resonances. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

15.
Summary In the present work an improvement of radiochemical neutron activation analysis for determination of nanogram levels of vanadium is described. The method is based on post-irradiation wet ashing and solvent extraction of vanadium with N-benzoyl-N-phenyl-hydroxylamine (BPHA) forming a violet chelate complex in strongly acidic medium. For quality assurance purposes a procedure for determination of the overall chemical yield using spectrophotometry of the V-BPHA complex is described, and possible interferences are evaluated. The procedure was applied to the determination of vanadium in reference materials and selected food samples from Slovenia.  相似文献   

16.
The Canadian Nuclear Fuel Waste Management Program involves both field and laboratory research, to assess the concept of disposal of nuclear fuel wastes at depths of up to 1000 m in plutonic rocks. This research program is multifaceted and requires data from a large number of disciplines, such as geology, geochemistry, hydrogeology, civil and mining engineering, chemistry, solid state science, environmental science, and meteorology. In many of these disciplines, nuclear analytical chemistry plays a major role. Examples of the application of nuclear analytical chemistry, including radiochemical separation and instrumental neutron activation analysis, will be discussed.Issued as AECL-8748.  相似文献   

17.
Isotopic analyses of radioactive materials such as irradiated nuclear fuel are of major importance for the optimization of the nuclear fuel cycle and for safeguard aspects. Among the mass-spectrometric techniques available, inductively coupled plasma mass spectrometry (ICP-MS) and thermal ionization mass spectrometry are the most frequently applied methods for nuclear applications. Because of the low detection limits, the ability to analyze the isotopic composition of the elements and the applicability of the techniques for measuring stable as well as radioactive nuclides with similar sensitivity, both mass-spectrometric techniques are an excellent amendment to classical radioactivity counting methods. The paper describes selected applications of multicollector ICP-MS in combination with chromatographic separation techniques and laser ablation for the isotopic analysis of irradiated nuclear fuels. The advantages and limitations of the selected analytical technique for the characterization of such a heterogeneous sample matrix are discussed.  相似文献   

18.
19.
 The role of matrix reference materials in the process of demonstrating the degree of equivalence of measurement results obtained from intercomparisons is outlined, reviewing exemplary selected experience gained at BAM regarding the determination of organic contaminants in environmental matrices. The specific characteristics of reference materials employed in the process of demonstrating equivalence between laboratories in the course of proficiency testing as well as the development, comparison and validation of methods are elaborated. The demand is for series of appropriately characterised samples which are fit for the purpose and it is seen from representative examples that the utilisation of such tailor-made RM designed to tackle the specific need of an analytical problem dominates over certified matrix reference materials in this context. Concluding, the role of certified matrix reference materials in quality assurance is briefly looked at both from the user’s and providers’ points of view. Received: 9 September 2002 Accepted: 16 December 2002 Presented at CERMM-3, Central European Reference Materials and Measurements Conference: The function of reference materials in the measurement process, May 30–June 1, 2002, Rogaška Slatina, Slovenia Correspondence to R. Becker  相似文献   

20.
V Lupsina  M Horvat  Z Jeran  P Stegnar 《The Analyst》1992,117(3):673-675
Epiphytic lichens have long been considered to be reliable bioindicators of air pollution. In the present study only one lichen species, Hypogymnia physodes (L.) Nyl., was chosen; this species is very often used for biomonitoring in Europe. Total mercury and methylmercury were determined in lichens taken from various polluted and unpolluted locations in Slovenia, including a mercury mining area around Idrija. Additionally, total gaseous mercury in air was also determined at several sampling points.  相似文献   

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