[en] In this paper the application of EDXRF, in combination with a relatively simple preconcentration technique for quantitative determination of uranium in water, is described. The preconcentration step implies the precipitation of uranium ions with a non-specific chelating reagent, ammonium-1-pyrrolidine dithiocarbamate (APDC), in presence of a co precipitant. The precipitate is collected on a Millipore filter, which is measured in the XRF system. Minimum detection limit results at 0.15 micrograms uranium corresponding to 0.3 micrograms/liter for 500 ml sample. The precision at 5 micrograms/liter level, expressed as relative standard deviation of 10 repeated measurements is 7%. Finally values of uranium concentration in seawater samples of the Albanian Adriatic and Ionian coast, obtained via this method, are presented. (author)

[en] In the period between March and May 1998, fifty aerosol samples were collected in two stations in the city of Tirana. The first station was situated at the urban area, while the second one was near the Centre of the city. The total aerosol samples were collected in TFA-$1 filters using high volume pumps. An experimental EDXRF instrument was used for the determination of the concentrations of 15 elements in the loaded aerosol filters. The analytical data obtained, allowed the calculation of the mean elemental concentrations in the aerosol and their crustal enrichment factors. The applications in the aerosol and their crustal enrichment factors. The application of multivariate methods (Factor Analysis) allowed the identification of the main aerosol sources. Along with the soil dust and sea salt particles, which are the main natural sources, there are clearly identified two other anthropogenic sources related with oil combustion and waste incineration.(authors)

[en] Preconcentration of trace transition and heavy metal ions by precipitation with APDC has been combined with energy-dispersive X-ray fluorescence for environmental sea water analysis. The preconcentration procedure implies adding of 500 μg Mo ion and 10 ml of 1 % water solution of APDC to a 500 ml water sample at pH 4, filtering off on a Millipore filter and analyzing after drying. Realistic detection limits are at 1 μg * l^-1 level and precision varies between 10 - 25% at about 5 μg * l^-1 level, depending on the element. Eleven sea water samples, covering Albanian Adriatic and Ionian coast, are analyzed for trace metal ions. (author) 8 refs.; 2 figs.; 5 tabs

[en] The analytical parameters obtained during the application of EDXRF spectrometry for the analysis of geochemical soil and sediment samples, are presented. The results are used for the geochemical mapping of Albania. Thick pellets of samples were measured in a secondary target excitation EDXRF system, using Mn and Mo secondary targets for excitation of low- and medium- Z elements, respectively. Ba and some rare earth elements were determined using an Am-241 source. The program COREX was used for calculating the concentrations of the elements excited by secondary targets and the method of the Compton scattered peak for the elements excited by the source. Depending on the composition of the samples 20 to 30 elements were determined. The recommendations of the International Geochemical Mapping Project IGCP-259 were used as guidelines for the evaluation of the analytical parameters. EDXRF spectrometry shows acceptable values of the detection limits for most of the determined elements. Precision and accuracy of the determinations were evaluated by the measurements of a series of standard reference materials recommended for use as primary standards in geochemical mapping. The intercomparison of the results with an independent laboratory is also discussed. In most of the cases, the results are satisfied the statistical tests and recommended criteria for geochemical mapping activities

[en] The paper describes a portable XRF spectrometer based on radioisotope excitation and a Peltier-cooled Si-PIN X ray detector as well as the analytical parameters of the instrument for the analysis of soil and sediment samples. Spectrum processing was done by using the AXIL program, and quantification was based on the COREX procedure or fluorescence to Compton ratio approach. The in situ results were compared with the laboratory measurements, and major discrepancies were attributed to the heterogeneity effects. The method was successfully applied for identification of the so-called hot spots of pollution in the over-bank sediments. (author)

[en] Full text: The activities on Energy-Dispersive X-ray Fluorescence Laboratory at the Institute of Nuclear Physics (INP) in Tirana, Albania started about 30 years ago from using simple systems consisting of single channel analysers, radioisotope sources and gas proportional or scintillation counters along with balanced filters for the separation of analytical lines. These systems were applied for the determination of single elements. A few portable prototypes were developed and successfully used for the determination of chromium and copper in ores, both in the lab and institute (ore processing plants) conditions. Later, through different TC projects with IAEA, the lab has been equipped with the following systems: X-ray tube excited EDXRF spectrometer with secondary target excitation; radioisotope excited EDXRF system; TXRF module; field portable XRF system based on a Cd-109 disc source; Si-PIN detector and pocket MCA. From the beginning our work has been focused on research, applications and training. Due to the fact that our EDXRF systems are made of different parts that are put together, our research activities are mainly related to optimization of excitation geometry and the development of optimized analytical procedures for the analysis of different group of elements in several kinds of samples. Some of these procedures include: determination of major and minor elements in soils, sediments, mineral ores and different type of rocks; determination of sulphur and some trace elements (V, Ni, etc.) in oil, bitumen and asphaltene; determination of some trace metals in sea and surface waters; determination of elemental composition of aerosols loaded on filters; determination of some trace elements in biological samples. An important point of our work is related with the quality of the analytical results. For this reason we have participated in some of the intercomparison runs organized by AQCS of the IAEA and in the GeoPT proficiency tests. In most cases our reported results have been in good accordance with the respective accepted or recommended values. Based on the advantages of EDXRF and on the fact that our lab is the only one in the country using this analytical technique, our group has been involved in several research projects and applications in the fields of geology, geochemistry, environmental monitoring, archaeology, etc. Some of the projects carried out during the last years are summarized bellow: geochemical mapping of Albania; national monitoring program for water and air pollution; technological study of Illyrian terracotta of Aphrodite and related ceramics of Hellenistic period from Belesh, Albania; identification of inorganic pigments used in old Albanian icons by TXRF; assessment of copper pollution in over-bank sediments of Mati river by in-situ measurements using a FPXRF instrument; identification of late-Byzantine and post-Byzantine wall paintings? materials and technology in Albania; mutual influence between Albanian and Greek iconographers; the study of ancient silver coins minted by Illyrian king Monounios (3-d century BC) and their comparison with same type and period silver coins from the cities of Dyrrachion and Korkyra. Lately, FPXRF system is being used for new in-situ applications like assessment of pollution of soils and sediments, and analysis of different cultural heritage objects (metals, stones, paintings). Training is provided for the students of Physics, Chemistry and Geology at both undergraduate and postgraduate levels (author)

[en] Full text: The importance of aerosol composition study is directly related with the specific role that aerosol particles play on human health and in different atmospheric parameters. The air pollution monitoring in Tirana has started long ago by measuring some common pollutants, but only during the last years a few attempts have been made for the study of aerosol composition. These were based on the analysis of total aerosol samples collected on cellulose filters using energy dispersive X ray fluorescence (EDXRF) spectrometry. Recently, with the support of the Albanian Ministry of Environment, an aerosol sampling campaign was organized in Tirana. Two different stations were selected for collecting aerosol samples. The first was situated in the centre of the city while the second, in a clean area, near the top of the mountain Dajti. In each of the stations total and size-fractionated aerosol samples were collected respectively on TFA-41 cellulose filters using high volume pumps and on Nuclepore filters using stacked filter unit sampler. An experimental EDXRF system was used for the determination of the concentrations of about 15 elements in the aerosol-loaded filters. The analytical data obtained allowed the calculation of the mean elemental concentrations in the aerosol and their crustal enrichment factors. The application of multivariate methods (Factor Analysis) allowed the identification of the main aerosol sources. (author)

[en] We have studied 39 samples of fragments from ceramic roof tiles with different stamps(Diamalas and Heraion), dated between 330 to 170 BC and found at the archaeological site of Dimales, some 30 km from the Adriatic coast. The data from these samples were compared with those obtained from 7 samples of similar objects and period with the stamp ^Heraion^, found at the archaeological site of APOLLONIA. The samples were analyzed by energy-dispersive X -ray fluorescence(EDXRF), using of the x-ray lines of the elements to the intensity of the Compton peak. The results have been treated with diverse multivariate methods. The application of hierarchical cluster analysis and factor analysis permitted the identification of two main clusters. The first cluster is composed from the ''Heraion'' samples discovered in Apollonia, while the second comprises all the samples discovered in Dimale independent of their stamp. (authors)

No abstract available

[en] In this paper are presented some results of an archaeometric investigation performed on several glass mosaic tesserae from Early Christian basilicas from different sites in Albania, belonging to V–VI century AD. While, during the last years there has been an increasing interest from both archaeologists and scientists for the study of glass archaeological artifacts found in Albania, the present study constitutes the first attempt to study the glass mosaic tesserae. A multi analytical approach, which includes optical microscopy, scanning electron microscopy equipped with energy dispersive spectrometer (SEM–EDS), micro X–ray fluorescence and Raman spectroscopy, is used during the investigation. The main objective of the study is the characterisation of the type of materials, glass matrix and coloring and opacifying agents, used for their production as well as the investigation of the microstructures of opaque coloured glass mosaics tesserae. Most of the glass tesserae have the characteristic soda-lime-silica composition typical for the Roman glass. Compounds of Mn, Fe, Cu, Pb, Sn, Co were used as colorants in tesserae of different colours, while apart from bubbles and mineral inclusions SnO_2 has been used as opacifier. Thin Au foils were used for the gold coloured tesserae. (author)