Abstract: Trace amounts of heavy metals were preconcentrated on discs of polyurethane (PU) foam loaded with ammonium diethyldithiocarbamate (DDTC), to increase the sensitivity of XRF. Since the diameter of the cavities in the open-cell PU foams reaches 30300 μm, considerable heterogeneity effects might occur, which could reduce the accuracy of the method. The possible systematic error introduced by considering the sample to be homogeneous is calculated using the Berry et al. model. The calculations show that the underestimation of the absorption correction factor when considering the sample as being homogeneous is less than 2% for high-Z elements when the sample thickness is at least 2 mm. The detection limits are also around the minima for this thickness.

Abstract: The heavy metal analysis around Iskenderun Bay in Turkey was carried out using mosses, soils, mussels, and sediments. This region is one of the most industrial areas of Turkey, including iron-steel plants, beverage, liquefied petroleum gas (LPG) plants, and oil transfer docks. Energy dispersive X-ray fluorescence spectrometry (Epsilon 5, PANalytical, Almelo, The Netherlands) was used to analyze all samples. V, Cr, Mn, Fe, Ni, Cu, Zn, As, and Pb elements were observed in all samples studied. Although Ce was detected in some mosses and soils, Sn was detected only in some moss samples. Pb concentrations in the moss samples are higher than the soil, the mussel, and the sediment samples. This can be attributed to the mosses that absorb heavy metals such as Pb easily from the air. As the aim of this study was to analyze heavy metals, the evaluation of these elements with their potential hazards for ecology and humans is briefly discussed

Abstract: Folding aerosol loaded filters in two with the loaded side inwards during the X-ray analysis not only reduces possible filter heterogeneity effects and improves sample protection, but also increases the sensitivity and renders filter paper absorption corrections simple and more accurate in many instances. It is shown that folding an aerosol loaded Whatman filter paper during Kα X-rays counting leads to an increased sensitivity for all elements up from calcium, scandium or titanium (depending on the sensitivity definition and on the aerosol load) and for all elements up from phosphorus, sulphur or chlorine in the case of the Nuclepore filter. Although the absorption by the filter, into which the aerosol penetrates to some extent, is always more important in the sandwich than in the usual geometry, the dependence of the absorption correction on the usually unknown average deposition depth is less pronounced. Assuming all the aerosol material to be collected at the very surface of the filter and hence being present in the centre of the sandwich to be analysed, leads to an extremely simple filter paper absorption correction which is less prone to uncertainties than more sophisticated corrections in the usual geometry requiring additional measurements. This is the case for all elements up from potassium on Whatman filters and up from phosphorus on Nuclepore filters.

Abstract: The ArmstrongBuseck correction for absorption effects in electron probe x-ray microanalysis of particles considers seven specific particle shapes, and for these geometries exact correction equations are used. This procedure implies that the analyst has to associate the particle to be analysed with a certain particle type; an arbitrary relative thickness is sometimes assumed. A theoretical study was made of this absorption correction as a function of the particle composition, type and thickness for micrometre-sized particles. It appears that a correct choice of the particle type is critical. However, when the analytical results are normalized to 100%, the differences between the models are much less pronounced, and it is justified to assume a spherical model in all cases.

Abstract: A new equation for predicting the generated bremsstrahlung background intensity in electron-probe x-ray microanalysis has been verified experimentally. This equation is applicable to all bulk composite specimens and reduces to Kramers' equation for pure elements only. The experimental verification has been carried out for Al2O3, Fe2O3 and ZrO2 with radiation energies from 4.2 to 14.8 keV. The predicted bremsstrahlung intensities are in good agreement with the experimental data.

Abstract: A semi-empirical approach is described for determining the mass per unit area of a sample being analysed. The method can be used to estimate the concentration of minor and trace elements in matrices containing a substantial amount of light elements. The procedure utilizes the coherently and incoherently scattered radiation induced in the sample by the filtered continuum radiation of a rhodium x-ray tube. The relationship between the intensity of the scattered radiation per unit mass and the average atomic number of the sample is established via calibration graphs, which can be applied for different x-ray tube voltages and for different primary beam filters. The overall procedure was validated by the analysis of several geological standards, deposited as thin slurries of unknown thickness either on Mylar foil or on Nuclepore filters.

Abstract: This paper critically compares the performance of four non-invasive techniques that match the accuracy, flexibility, time-efficiency, and transportability required for in situ characterization of leaded glass windows: macroscopic X-ray fluorescence imaging (MA-XRF), UV-Vis-NIR, Raman spectroscopy, and infrared thermography (IRT). In order to compare the techniques on equal grounds, all techniques were tested independently of each other by separate research groups on the same historical leaded window tentatively dated to the 17th century, without prior knowledge. The aim was to assess the ability of these techniques to document the conservation history of the window by classifying and grouping the colorless glass panes, based on differences in composition. IRT, MA-XRF and UV-Vis-NIR spectroscopy positively distinguished at least two glass groups, with MA-XRF providing the most detailed chemical information. In particular, based on the ratio between the network modifier (K) and network stabilizer (Ca) and on the level of colorants and decolorizers (Fe, Mn, As), the number of plausible glass families could be strongly reduced. In addition, UV-Vis-NIR detected cobalt at ppm level and gave more specific information on the chromophore Fe2+/Fe(3+)ratio. Raman spectroscopy was hampered by fluorescence caused by the metal ions of the decolorizer in most of the panes, but nevertheless identified one group as HLLA.

Abstract: In this study, the results of analysing of a series of 16th-19th century painted enamel objects of the Limoges School currently in collections in three Dutch and Flemish museums by means of portable and micro x-ray fluorescence analysis (PXRF and µ-XRF) and electron probe micro analysis (EPMA) are presented. The aim of the investigation was the authentication of specific pieces. Therefore, the glass compositions as well as the (glass) colouring agents used by the Limoges' artists were studied as a function of the age of the objects. Due to the evolution of these properties, it is possible to approximately date these objects based on their chemical composition. The complete émail peint collection of the Museum Boijmans-Van Beuningen (Rotterdam, The Netherlands), consisting of 20 émail peint plaques, was analysed with µ-XRF. Quantitative information was obtained by EPMA analysis of 15 enamel fragments of objects from museum and private collections in the Low Countries. PXRF analyses were performed on the painted enamel collection of the Antwerp Vleeshuis Museum (13 objects) and the Mayer van den Bergh Museum (4 objects) and on a set of 18 plaques that were donated to the Boijmans-Van Beuningen Museum by a private collector. The results obtained by means of EPMA, µ-XRF and PXRF proved to be useful in the discrimination of 16th century painted enamel objects from those of the19th century. From a total of 70 objects examined, 2 objects (OM964A and OM993) featured a chemical signature that deviated from the published literature composition and pigment use consistent with its presumed period of manufacture.