Elemental composition and microstructure analysis of a rabbit urolith

Following physical examination and radiography analysis, cystotomy was performed to remove a rabbit’s single bladder stone. This rabbit urolith was analyzed by X-ray fluorescence spectrometry (EDXRF) and scanning electron microscopy (SEM). The EDXRF technique was successful for the determination of major elements (Ca, Mg, P, K and S) and presented sufficient sensitivity to also trace elements (Sr, Fe, Cu, V, Cr, Mn, Zn and Pb) determination. The results showed significant quantitative and structural variations among the urolith regions. The EDXRF technique using the fundamental parameters method and SEM attend as complementary techniques that can be useful in the management of urinary stone analysis.     

EDXRF as an analytical tool in art: Case studies from pigment identification and treatment assessment

Energy dispersive X-ray fluorescence (EDXRF) was employed for the identification of pigments decorating Hellenistic figurines, and the assessment of the efficiency of a treatment with barium hydroxide applied to stone. Elements present in the colored areas of the figurines, as well as the treated stone was identified by EDXRF. These data together with complementary information obtained by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis (XRD) led to the identification of several precious pigments. As far as the treatment efficiency is concerned, EDXRF analysis revealed that barium is unevenly distributed on the treated surface and reaches a maximum depth of 2.5 mm.     

EDXRF as an analytical tool in art: Case studies from pigment identification and treatment assessment

Energy dispersive X-ray fluorescence (EDXRF) was employed for the identification of pigments decorating Hellenistic figurines, and the assessment of the efficiency of a treatment with barium hydroxide applied to stone. Elements present in the colored areas of the figurines, as well as the treated stone was identified by EDXRF. These data together with complementary information obtained by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis (XRD) led to the identification of several precious pigments. As far as the treatment efficiency is concerned, EDXRF analysis revealed that barium is unevenly distributed on the treated surface and reaches a maximum depth of 2.5 mm.     

Elemental analysis of Cu−Ni and Nd−Al alloys and, nickel and iron powders by energy dispersive X-ray fluorescence (EDXRF) technique

Energy dispersive X-ray fluorescence spectroscopy (EDXRF) has been used for elemental analysis of Cu−Ni alloy, neodymium aluminide, and iron and nickel powder. The preparation of Cu−Ni alloy and neodymium aluminide has been carried out by aluminothermic reduction of mixed oxides of copper and nickel and neodymium oxide respectively. Aqueous electrorefining technique has been followed for the preparation of iron and nickel powder using Fe−Ni alloy as anode. The determination of major and trace elements present in the Cu−Ni and, electrolytically refined nickel and iron has been accomplished by EDXRF using Cd¹⁰⁹ radioisotope source. In the case of Nd−Al alloy Am²⁴¹ radioisotope source has been used. The rapid and multielement analysis of the thermit product by EDXRF has aided in the appropriate variation of the charge constituents during the standardization of the optimum charge composition for Cu−Ni alloy. EDXRF analysis of electrolytically refined nickel and iron revealed heavy contamination of iron in nickel as compared to that of nickel in iron. Neodymium content has been found to be 67.68% in Nd−Al alloy.     

X-ray spectrometry using polycapillary X-ray optics and position sensitive detector

Polycapillary X-ray optics (capillary X-ray lens) are now popular in X-ray fluorescence (XRF) analysis. Such an X-ray lens can collect X-rays emitted from an X-ray source in a large solid angle and form a very intense X-ray microbeam which is very convenient for microbeam X-ray fluorescence (MXRF) analysis giving low minimum detection limits (MDLs) in energy dispersive X-ray fluorescence (EDXRF). A new method called position sensitive X-ray spectrometry (PSXS) which combines an X-ray lens used to form an intense XRF source and a position sensitive detector (PSD) used for wavelength dispersive spectrometry (WDS) measurement was developed recently in the X-ray Optics Laboratory of Institute of Low Energy Nuclear Physics (ILENP) at Beijing Normal University. Such a method can give high energy and spacial resolution and high detection efficiency simultaneously. A short view of development of both the EDXRF using a capillary X-ray lens and the new PSXS is given in this paper.     

Determination of Cr,Fe, Co,Ni, Cu,Zn, As and Pb in liquid chemical waste by energy dispersive X-ray fluorescence

A method for simultaneous determination of Cr, Fe, Co, Ni, Cu, Zn, As e Pb in liquid chemical waste using Energy Dispersive X-Ray Fluorescence (EDXRF) technique was evaluated. A small sample amount (200 μL) was dried on a 6.35 μm thickness Mylar film at 60 °C and the analyses were carried out using an EDXRF spectrometer operated with an X-ray Mo tube (Zr filter) at 30 kV/20 mA. The acquisition time was 300 s and the Ga element was utilized as internal standard at 25 mg/L for quantitative analysis. The method trueness was assessed by spiking and the detection limit for those elements ranged from 0.39 to 1.7 mg/L. This method is notable because it assists the choice of the more appropriated waste treatment procedure, in which inter elemental interference is a matter of importance. In addition, this inexpensive method allows a non-destructive determination of the elements from ₁₉K to ₉₂U simultaneously.     

Determination of tungsten in ores by energy dispersive X-ray fluorescence analysis

The possible determination of tungsten in low grade ores from Northern India, Rajasthan State has been explored by energy dispersive X-ray fluorescence analysis /EDXRF/ technique using radioisotope based excitation of W L X-rays and high resolution Si/Li/ detector system. Finely powdered ore has been diluted with optimal quantity of cellulose and converted into pellets to make it suitable for X-ray analysis after homogenization. The experiments have shown the minimum detectable limit of 33 ppm in diluted matrix. The results are compared with the spectrophotometric stannous chloride-thiocyanate method. EDXRF appears to be encouraging for routine and precise analysis of tungsten in low grade ores.     

Energy dispersive X-ray fluorescence analysis of gallstones

The elemental analysis of south Indian gallstones has been carried out using energy dispersive X-ray fluorescence (EDXRF) spectroscopy. A number of important elements including Fe, Cu, Zn, Br, and Pb were estimated from the EDXRF spectra. The results are presented and discussed.     

Non-invasive identification of chemical compounds by energy dispersive X-ray fluorescence spectrometry, combined with chemometric methods of data evaluation

Chemicals from customers' returns have to be analyzed before they can be reused as raw materials in production. A procedure for non-invasive qualitative analysis of compounds in a closed container based on energy dispersive X-ray fluorescence (EDXRF) spectrometry is described. EDXRF was chosen as method for noninvasive analysis of chemicals through PE bottle walls without opening the bottle. This analysis aims for a quick proof of correspondence between the declaration of a reagent on the label of the bottle and its content. This analytical result cannot be achieved by a mere evaluation of characteristic element lines in EDXRF-spectra in combination with the method of matrix correction or the method of mean atomic number. These methods take into account only a small part of the total information available in an X-ray spectrum. It is shown here that valuable additional information is extractable from the spectral ranges of the Compton-scattering and Rayleigh-scattering areas by the use of methods of multivariate data analysis, especially by principle component analysis (PCA). Regularized discriminant analysis (RDA) was employed to establish a classification scheme for unknown samples.     

EDXRF analysis of some samples of cigarette paper

The effects of tobacco on human health have been widely investigated and documented However, there are not too many specific reports on the potential risk associated to the presence of metals in the paper employed for cigarettes fabrication Even more, there is a lack of national and international norms in this respect. Otherwise, in the literature INAA appears as the unique method for wrapping paper analysis. Therefore, without a nuclear reactor available at the National University of Mexico (UNAM), EDXRF was selected with the aim to explore the possibility to apply this method, instead of INAA, to the analysis of wrapping paper assuming this task, at the beginning, as a supplement to a previous research which was recently presented (2005).¹ The analytical work was developed on the wrapping paper of eight of the most known marks of cigarettes in Mexico, in two non-destructive stages: a first survey, by the classical technique of energy dispersive X-ray fluorescence (EDXRF), used a 1 11 GB qradiation source of ²³⁸Pu and a SiLi detector. In the absence of standard reference materials for cigarette’s paper, the SRM-1832 and 1833 were required for calibration, a fiberglass air filter was used as a secondary standard. The second stage was performed in a spectrometer TX-2000, anode of Mo, quantification software EDXRF32 (fundamental parameters). This paper presents a comparison of the obtained values with those found in the literature. The results show that the EDXRF method, in the Mo tube version, has the adequate precision and detection limits for the analysis of wrapping paper.     

Non-invasive identification of chemical compounds by energy dispersive X-ray fluorescence spectrometry, combined with chemometric methods of data evaluation

Chemicals from customers’ returns have to be analyzed before they can be reused as raw materials in production. A procedure for non-invasive qualitative analysis of compounds in a closed container based on energy dispersive X-ray fluorescence (EDXRF) spectrometry is described. EDXRF was chosen as method for non-invasive analysis of chemicals through PE bottle walls without opening the bottle. This analysis aims for a quick proof of correspondence between the declaration of a reagent on the label of the bottle and its content. This analytical result cannot be achieved by a mere evaluation of characteristic element lines in EDXRF-spectra in combination with the method of matrix correction or the method of mean atomic number. These methods take into account only a small part of the total information available in an X-ray spectrum. It is shown here that valuable additional information is extractable from the spectral ranges of the Compton-scattering and Rayleigh-scattering areas by the use of methods of multivariate data analysis, especially by principle component analysis (PCA). Regularized discriminant analysis (RDA) was employed to establish a classification scheme for unknown samples.     

Improvement of matrix effects correction in X-ray fluorescence analysis through the optimum relation

A computer program for the optimization of relation for correction of matrix effects in Energy Dispersive X-Ray Fluorescence (EDXRF) analysis is described Program functioning and correction efficiency is studied experimentally in the case of silicate geological samples.     

EDXRF versus INAA in a pollution control of soil

Summary Elemental concentrations of soil samples collected in the vicinity of a Romanian fertilizer plant were determined by EDXRF and long half-life INAA. Lower limits of detection, obtained for various elements in soil by EDXRF technique with radioactive excitation sources (²³⁸Pu and ²⁴¹Am) and a HPGe detector are presented. Spurious effects characteristic for Ge detector X-ray spectrometry are evaluated and discussed, and methods to overcome this drawback are suggested. Special care was taken to subtract from the spectra the Ge Ka     

Mercury analysis in environmental samples by EDXRF and CV-AAS

The analysis of total Hg in various environmental matrices was investigated using energy dispersive X-ray fluorescence (EDXRF) for both powdered and digested samples and cold vapor atomic absorption (CV-AAS) for digested samples. Several microwave decomposition procedures were evaluated with respect to the determination of Hg by CV-AAS and EDXRF. The use of different acid mixtures, microwave power settings and decomposition times were compared as well as the analysis on wet and freeze-dried samples. A set of standard reference samples were used to evaluate the procedures: NBS Citrus leaves (1572), NRC Pine needles (1575), NRC Dogfish muscle tissue (DORM-2), NRC Dogfish liver tissue (DOLM-2), BCR Human hair (397), BCR Coking coal (181) and NRC Marine sediment (PACS-1). An H₂SO₄/HNO₃/H₂O₂ acid mixture was found to be optimal for the complete mineralization and digestion of biological samples for Hg by CV-AAS whereas for EDXRF both the HNO₃/H₂O₂ and H₂SO₄/HNO₃/H₂O₂ acid mixture gave good results. The detection limit of EDXRF could significantly be decreased (from 0.2 μg/g to 0.058 μg/g) by performing the analysis with digested samples. A good agreement was obtained between CV-AAS and EDXRF analysis. The obtained results were also in good agreement with certified values. The methods were applied to environmental samples (coal, trees, leaves, spinach, fish, sediments) and human hair in a coal mining area and in places where they use coal for cooking in Vietnam. Received: 24 February 1997 / Revised: 13 June 1997 / Accepted: 18 June 1997     

Identification of ancient gilding technology and Late Bronze Age metallurgy by EDXRF, Micro-EDXRF, SEM-EDS and metallographic techniques

A combination of analytical techniques capable of elemental and microstructural characterisation was used for the identification of ancient gilding technology and bronze metallurgy. EDXRF, micro-EDXRF, SEM-EDS analysis and metallographic examinations were applied in the study of artefacts dating to the end of the second millennium BC from Crasto de São Romão in Central Portugal. Results report to the finding of an exceptional gilded copper nail among bronze artefacts with 9 wt.% to15 wt.% tin and minute other metallic impurities. Additionally, analysis of a crucible fragment points out for bronze production at the archaeological site. EDXRF and micro-EDXRF analysis made on the copper nail showed that it was gilded only on the front side of the head, and that the gold layer has been lost in the most exposed areas. SEM-EDS analysis showed that the gold layer has 5–8 µm in thickness and is covered with a thick corrosion layer. The gilding technique is discussed based on the gold layer composition and gold/copper substrate interface. So far, this object seems to be the first diffusion gilded artefact identified in the Portuguese territory dated to Late Bronze Age.     

Soil characterization by energy dispersive X-ray fluorescence: sampling strategy for in situ analysis.

This work describes a sampling strategy that will allow the use of portable EDXRF (energy dispersive X-ray fluorescence) instruments for "in situ" soil analysis. The methodology covers a general approach to planning field investigations for any type of environmental studies and it was applied for a soil characterization study in the zone of Campana, Argentina, by evaluating data coming from an EDXRF spectrometer with a radioisotope excitation source. Simulating non-treated sampled as "in situ" samples and a soil characterization for Campana area was intended. "In situ" EDXRF methodology is a powerful analytical modality with the advantage of providing data immediately, allowing a fast general screening of the soil composition.     

Multielemental evaluation of garbage bags by EDXRF

Garbage bags have been broadly used for collecting household waste in Brazil and worldwide. Many of these bags are made from recycled polymers, and the presence of harmful elements is a matter of concern. In this study, an energy dispersive X-ray fluorescence (EDXRF) approach for direct analysis of garbage bags is proposed. The concentrations of K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr and Pb were determined in 14 garbage bags of different brands purchased from local markets in Piracicaba, São Paulo State, Brazil. The EDXRF technique proved to be an effective technique for multielemental, environmentally friendly and direct garbage bag monitoring. For most samples, Ca and Ti presented at minor concentration ranges and K, Cr, Mn, Fe, Ni, Cu, Zn and Pb at minor and trace levels. The EDXRF limits of quantification were K: 220; Ca: 112; Ti: 42; Cr: 19; Mn: 13; Fe: 9.2; Ni: 5.7; Cu: 5.3; Zn: 5.2; Br: 12; Rb: 20; Sr: 28 and Pb:17 μg g^–1. The samples had variable thicknesses, with a superficial density variation of 1.5 to 23% among the triplicates. The trueness of the method was checked by analysing the National Institute of Standards and Technology standard reference material SRM2783.     

Thickness measurement of semiconductor thin films by energy dispersive X-ray fluorescence benchtop instrumentation: Application to GaN epilayers grown by molecular beam epitaxy

The importance of thin films in modern high technology products, such as semiconductors, requires fast and non-destructive analysis. A methodology to determine the thickness of single layers with benchtop energy dispersive X-ray fluorescence (EDXRF) instrumentation is described and tested following analytical validation criteria. The experimental work was carried out on gallium nitride thin films epitaxially grown on sapphire substrate. The results of samples with layers in the range from 400 to 1000 nm exhibit a good correlation with the layer thickness determined by optical reflectance. Spectral data obtained using thin layered samples indicate the possibility to precisely evaluate layer thickness from 5 nm, with a low relative standard deviation (RSD < 2%) of the results. In view of the limits of optical reflectance for very thin layer determination, EDXRF analysis offers the potential for the thickness determination of such kind of samples.     

Preconcentration of rare earth quinolin-8-ol complexes onto activated carbon and determination by first-order derivative x-ray fluorescence spectrometry

A method is described for the determination of traces of rare earths using energy-dispersive x-ray fluorescence spectrometry (EDXRF) after preconcentration of their quinolin-8-ol complexes on activated carbon. Various parameters that influence the adsorptive preconcentration of rare earths on activated carbon, viz., pH, amounts of activated carbon and quinolin-8-ol, time of stirring and aqueous phase volume, were systematically studied. A numerical method based on a simple least-squares procedure using a fifth-order polynomial with 25 consecutive values was developed for smoothing and differentiation of EDXRF data which were previously digitized and averaged. First-order derivative EDXRF in conjunction with adsorptive preconcentration of activated carbon enables down to 10 ng ml^?1 of each rare earth element to be determined.