Authors:Guogang Jia, G. Torri, P. Innocenzi, R. Ocone, and A. Di Lullo
A method for the determination of low-level radium isotopes in mineral and environmental water samples by alpha-spectrometry
has been developed. Radium-225, which is in equilibrium with its mother 229Th, was used as a yield tracer. Radium were preconcentrated from water samples by coprecipitation with BaSO4and iron (III) hydroxide at pH 8-9 using ammonia solution, then isolated from uranium, thorium and iron using a Microthene-TOPO
chromatography column at 8M HCl, separated from barium in a cation-exchange resin column using 0.05M 1,2-cyclohexylenedinitrilotetraacetic
acid monohydrate at pH 8.5 as an eluant, and finally electrodeposited on a stainless steel disc in a medium of 0.17M (NH4)2C2O4at pH 2.6 and current density of 400 mA. cm-2, and counted bya-spectrometry. Optimum experimental conditions for radium separation, purification and electrodeposition
have been studied and discussed in the paper. The lower limits of detection of the method are 0.11 mBq. l-1for 226Ra, 228Ra and 224Ra, respectively, if 2 l of water are analyzed. The method has been checked with a certified reference material IAEA-Soil-6
supplied by the International Atomic Energy Agency and reliable results were obtained. Eighteen water samples collected in
Italy have been analyzed with the method, the mean radiochemical yields for radium were 86.2±6.5%. The obtained radium concentrations
were in the range of 0.50-60.8 mBq. l-1for 226Ra, of 0.10-25.7 mBq. l-1for 228Ra, and of£LLD-7.97 mBq. l-1for 224Ra. The 228Ra/226Ra and 224Ra/226Ra ratios were in the range of 0.189-4.45 and£LLD-0.941, respectively.
To satisfy the needs for industrial standards for thermal analysis in the Japanese polymer industry, round-robin tests of
differential scanning calorimetry (DSC), thermogravimetry (TG), thermomechanical analysis (TMA) and thermodilatometry (TD)
have been carried out recently. The results are discussed in this short review.
The DSC applications tested were not only for determination of transition temperature but also for measurements of the transition
heat and heat capacity. The TG task group did not aim at longterm thermal endurance studies, but relative thermal stability
in molding and estimation of filler content, residual solvent content, etc. TMA was found to be a useful tool for measuring
softening temperature and heat distortion temperature, especially for high-temperature engineering plastics, instead of the
Vicat test which has temperature limitations. For temperature calibration of DSC and TG, ICTA-NIST certified reference materials
were used together with other potential temperature standards; some inorganic substances and alloys were not found to be preferable
to pure metals. For TMA and TD metal plates were found to be very useful for temperature calibration. Analysis of the round-robin
test results also clarified present status of practical applications of thermal analysis, such as reproducibility and causes
Authors:R. Radhamani, P. Mahanta, P. Murugesan, and G. Chakrapani
A simple, rapid, effective and eco-friendly decomposition method is developed for the determination of uranium (U) by laser
induced fluorimetry (LIF). The salts of sodium di-hydrogen phosphate (NaH2PO4) and di-sodium hydrogen phosphate (Na2HPO4) were used in the ratio of 1:1 (phosphate flux) for the decomposition and dissolution of refractory, non silicate minerals
like ilmenite, rutile, columbite, tantalite, and xenotime. The effect of associated matrix elements (Ti, Fe, Nb, Ta, Mn and
Y present in the sample) on quenching of uranyl fluorescence was studied. The flux used for the sample decomposition has several
advantages. In the reported sample decomposition methods, α-hydroxy acids are used as complexing agents to prevent hydrolysis
and to get clear and stable solution. This solution can not be directly used for U determination by LIF as α-hydroxy acids
quench uranyl fluorescence, hence separation is required. In the present method no such separation is required. The flux itself
acts as fluorescence enhancing reagent and buffer (maintaining the optimum pH of 7.1 ± 0.1). The fused melt of the flux mixture,
when disintegrated in water, gives clear and stable solution and has high tolerance for most of inorganic quenchers compared
to reported phosphate buffers. Also just by dilution (due to high sensitivity of LIF), the concentration of quenchers could
be brought down well within the tolerance limit. The accuracy and precision of the method was evaluated by analyzing Certified
Reference Materials (IGS-33 and IGS-34 of Institute of Geological Sciences, UK) and Synthetic Minerals. The accuracy of the
data is further evaluated by comparing with standard decomposition methods. The results are well within the experimental error.
The RSD of the method is ±10% (n = 6) at 10 ppm level for Ilmenite and for other minerals the RSD of the method is ±5% (n = 6) at 50 ppm level. The method is being routinely applied to various refractory samples received from Rare Metal and Rare
Earth Investigations for determination of uranium by laser fluorimetry.
Authors:Akifumi Eguchi, Takeshi Enomoto, Norimichi Suzuki, Miho Okuno, and Chisato Mori
= 7) of certifiedreferencematerial (SRM 1957).
Passing–Bablok regression [ 17 ] and Pearson's correlation coefficients were used to investigate the agreement between the original
Authors:D. Trbović, T. Polak, L. Demšar, N. Parunović, M. Dimitrijević, D. Nikolić, and V. Đorđević
their reproducibility limits and make recommendation for their use in laboratory practice [ 41 , 42 ], to evaluate and possibly improve analytical methods or laboratory performance, or to certifyreferencematerials [ 43 – 45 ]. Due to the heterogeneity
Authors:Elise Ivarsen, Christoffer P. Andersen, Sabine M. Jensen, Carsten T. Pedersen, and Anders K. Svaneborg
iron and zinc, the accuracy of the methods was further tested by analysis of certifiedreferencematerial for food element analysis, brown rice flour NMIJ CRM7532-A, the reference material had a mean recovery of 101% ( n = 16) for iron and 97% ( n
Authors:Elena Badea, Giuseppe Della Gatta, and Petru Budrugeac
be less reliable, since DSC parameters can vary with the collagen hydration level.
Certifiedreferencematerials such as naphthalene, benzoic acid and gallium were used to check the calibration constants supplied by SETARAM in the working