γ-Ray absorption spectroscopy has been used to accurately determine the Si and Ge content in SiGe alloys. This technique provides
a fast, accurate, and non-destructive method for determining concentrations of components in binary systems.
Normally, gamma-ray spectroscopy is performed by equipment positioned in the SLOWPOKE-2 Facility at the Royal Military College; however, there have occasionally been requirements for analyses externally. A transportable gamma spectroscopy system was thus assembled by acquiring a commercially available multichannel analyzer, analysis program and detector, and by designing and constructing a transportable shielding castle. It was then used to take measurements of fission product concentrations at several research reactors.
Synthetic Fe—Mn alkoxide of glycerol samples are submitted to controlled heating conditions and examined by IR absorption spectroscopy. On the other hand, the same sample is studied by infrared emission spectroscopy (IRES), upon heating in situ from 100 to 600°C. The spectral techniques employed in this contribution, especially IRES, show that as a result of the thermal treatments ferromagnetic oxides (manganese ferrite) are formed between 350 and 400°C. Some further spectral changes are seen at higher temperatures.
Authors:Ádám Dávid, Emil Mincsovics, István Antal, Éva Furdyga, Zsolt Zsigmond, and Imre Klebovich
We report a new combination of overpressured-layer chromatography (OPLC) with near-infrared (NIR) spectroscopy for pharmaceutical analysis. Different pharmaceutical preparations containing caffeine, paracetamol, and acetylsalicylic acid as model compounds were separated by OPLC. The band density in the solid phase after OPLC was suitable for study of the separated components directly on the layer by NIR spectroscopy.We have demonstrated the applicability of rapid OPLC separation combined with UV densitometry and NIR spectroscopy for both qualitative and quantitative analysis. This OPLC-UV-NIR technique is thus suitable for rapid, nondestructive investigation of multicomponent pharmaceutical preparations and enables a different type of pharmaceutical analysis, e.g. starting-material tests, in-process control, end-product control, stability testing, etc. Another benefit of this newly developed combination of rapid off-line techniques is the possibility of simultaneous collection of qualitative and quantitative chromatographic and spectral information.
Authors:M. Oshtrakh, V. Semionkin, O. Milder, and E. Novikov
Mössbauer spectroscopy is a useful technique for biomedical applications. To increase analytical possibilities and quality
of its biomedical applications a new Mössbauer spectrometric system was developed. This system based on a highly stable, sensitive
and precision spectrometer SM-2201 with high velocity resolution and a temperature variable liquid nitrogen cryostat with
a moving absorber. The first results of Mössbauer spectroscopy with high velocity resolution demonstrated a decrease in the
experimental error in the determination of 57Fe hyperfine parameters and, therefore, an increase of accuracy in analysis of small variations of the iron electronic structure,
as well as more reliable fitting of complicated spectra.
Authors:O. B. Oshtrakh, M. I. Milder, and V. A. Semionkin
An analysis of the iron state in commercial pharmaceuticals containing ferric and ferrous iron compounds, which are used for
treatment of iron deficiency, was made by Mössbauer spectroscopy. Small variations of the FeOOH cores of injectable iron-dextran
complexes were observed. The presence of ferrous impurity in iron-dextran complexes was found. Characterization of the iron
state in vitamins and dietary supplements containing ferrous compounds was made. The presence of ferrous and ferric impurities
and iron compounds that were in disagreement with compounds announced by the manufacturer was detected by Mössbauer spectroscopy.
The advantage of , -coincidence spectroscopy for the measurement of radiochemically separated nuclides of low radioactivity is demonstrated. The background is reduced by about three orders of magnitude, and its main component, the natural radioactivity of the laboratory walls, is reduced by about four orders of magnitude. The contribution of cosmic rays becomes important at higher energies and within large shields.
Beta-gamma-coincidence spectroscopy is a sensitive measurement technique in reactor neutron activation analysis. A simple
counting device with a 4″×3″ NaI(Tl) crystal and a 32 mm×2 mm plastic scintillator is described and the advantage of the β-γ-coincidence
technique, which has been successfully applied to the determination of iron and other impurities in semiconductor silicon,
Flameless atomic absorption spectroscopy has been successfully applied to the analysis of trace levels of gold, silver and
cobalt in milligram quantities of aluminum. The two-line method of background correction was used with good, but not total,
success. The reproducibility of the measurements was excellent, and the results compared very well with the expected values.
Authors:E. Kuzmann, Z. Klencsár, Z. Homonnay, A Vértes, G. Braga, A. De Oliveira, V. Garg, M. Bódogh, I. Kotsis, and A. Nath
57Fe and 151Eu Mössbauer spectroscopy as well as RF susceptibility measurements were applied to study the effects of Pr substitution either into the rare earth or into the Ba site in Eu1–xPrxBa2Cu3O7– and EuBa2–xPrxCu3O7–, respectively. Site mixing of Pr between the rare earth and Ba sites could be excluded by the utilization of 57Fe Mössbauer spectroscopy. It was found that there exists a correlation between the 151Eu isomer shift and the onset temperature of the superconducting transition independent of the location of Pr. RF susceptibility measurements provide an evidence for a difference in the magnetic moment of Pr substituted for the Eu or Ba sites. The obtained results can be explained by hole filling as the dominant effect of Pr substitution.