共查询到20条相似文献,搜索用时 15 毫秒
1.
Keshav Chander S. P. Hasilkar A. V. Jadhav H. C. Jain 《Journal of Radioanalytical and Nuclear Chemistry》1993,174(1):127-132
A method for the sequential determination of thorium and uranium has been developed. In the sample solution containing thorium and uranium, thorium is first determined by complexometric titration with ethylenediaminetetraacetic acid (EDTA) and then in the same solution uranium is determined by redox titration employing potentiometry. As EDTA interferes in uranium determination giving positive bias, it is destroyed by fuming with HClO4 prior to the determination of uranium. A precision and accuracy of better than ±0.15% is obtained for thorium at 10mg level and uranium ranging from 5 mg to 20 mg in the aliquot. 相似文献
2.
Gurupada Banerjee 《Fresenius' Journal of Analytical Chemistry》1955,146(6):417-422
Summary A rapid titrimetric method for the estimation of thorium in the range from 5 to 88 mg. in a 50 ml. of final volume has been developed which involves the adjustment of Ph at 3.0, addition of 2 ml. of 0.02% SPADNS indicator, dilution to volume and titration with standard NaF until the colour obtained matches a blank containing the buffered solution of the indicator alone. The method has been standardised against known amounts of thorium and a calibration curve relating the titre of the fluoride solution to thorium content has been prepared. Interferences of various cations and anions have also been studied. From the results, the quantitative nature of zirconium interference has been confirmed. The method for the determination of thorium is very rapid and the colour change being sharp from blue-violet to scarlet-red, the detection of endpoint is not at all difficult.The author wishes to thank Dr. A. K. Ghosal, Principal, Darjeeling Government College, for providing Laboratory facilities and Prof. P. Ray and Dr. A. K. Mukherjee of the Indian Association for the Cultivation of Science, Calcutta for their encouragement in the research work. 相似文献
3.
A new method for the titrimetric determination of perchlorate has been developed, based on its reduction to chloride by iron(II) in a strong sulphuric acid medium at high temperature. The effect of variables, such as the sulphuric acid concentration, the temperature and the period of heating, on the extent of reduction has been studied and the optimal conditions for analytical determination of perehlorate derived. 相似文献
4.
The direct titration of ferricyanide ions with the mercurous-thiocyanate system is studied, the influence of pH, thiocyanate concentration, time and temperature being considered. The standard deviation of the proposed method is 0.26 per cent. 相似文献
5.
J. V. Kamat J. S. Gamare K. Jayachandran Suresh K. Aggarwal 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(2):1431-1434
A biamperometric methodology for the sequential determination of thorium (Th) and uranium (U) was developed. In the sample solution containing Th and U, Th was first determined by complexometric titration based on the electrochemical behaviour of EDTA maintaining a potential of ≥200 mV between the twin Pt electrodes. This was followed by the redox titrimetric determination of U employing biamperometry to detect the end point. Prior to the determination of U, EDTA was destroyed by fuming with concentrated HClO4 to eliminate its interference in the U determination. The method was tested for the determination of Th and U in (Th, U) O2 samples containing 4 mg of Th and 2–8 mg of U, with precision and accuracy of better than 0.3 %. 相似文献
6.
S. B. Manohar S. K. Aggarwal S. M. Deshmukh A. R. Parab P. P. Burte H. C. Jain Satya Prakash 《Journal of Radioanalytical and Nuclear Chemistry》1981,63(1):145-153
A gamma-spectrometric method using an intrinsic high resolution germanium detector has been developed for the determination
of isotope ratios of plutonium from samples in solution form. The method is based on the assay of low energy gamma-rays of238Pu,239Pu,240Pu and241Pu and does not require the use of branching intensities or the knowledge of detection efficiencies for different gamma rays.
Since low energy gamma-rays are used, the effect of241Am has also been studied. It is found that results are not affected up to 0.5 wt% of241Am in plutonium samples. An accuracy of 3% is achievable in the determination of240Pu/239Pu and241Pu/239Pu atom ratios as demonstrated by carrying out measurements on isotopic standards of plutonium. 相似文献
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P. Sivakumar S. Meenakshi S. V. Mohan R. V. Subba Rao M. Venkataraman 《Journal of Radioanalytical and Nuclear Chemistry》2012,294(1):93-96
The spent fuel from Fast Breeder Test Reactor of various burnups from 25 to 155?GWd/te is being reprocessed in CORAL (COmpact Reprocessing of Advanced fuels in Lead shielded cell) using a modified PUREX (Plutonium Uranium Recovery by EXtraction) process. Total plutonium (Pu238, 239, 240, 241 & 242) concentration in the sample is analysed by HTTA (Thenoyl Trifluoro Acetone) extraction method wherever interference from other alpha emitting nuclides (Raffinate) and bulk natural uranium (uranium products) are present "as reported by Milyukov et al. (Analytical chemistry of plutonium, 1967) and Natarajan and Subba Rao (BARC, pp. 38?C43, 2007)". This method requires the addition of corrosive reagents such as NH2OH.HCl which is a problem in waste disposal for reduction. A salt-free reagent such as Hydroxyurea is studied as a reducing agent which has the ability to reduce both Pu(VI) and Pu(IV) to Pu(III) "as reported by Zhaowu (260(3):601?C606, 2004) and Zhaowu (262(3):707?C711, 2004)". Pu(III) thus formed can be easily oxidised to Pu(IV) by NaNO2 for the extraction of Pu by HTTA. 相似文献
10.
A spectrophotometric method is described in which microgram amounts of plutonium can be determined in the presence of uranium,
thorium, fission products and cladding materials. Plutonium is extracted with TTA in xylene and reextracted into a solution
of Arsenazo III. Zirconium is masked by a Fe(III)-EDTA mixture, fluoride ions by Al(III). 2 to 40 μg of plutonium are required
for one analysis. The standard deviation is 1.3% at 15 μg plutonium. 相似文献
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A sensitive procedure for the determination of sulphide is described. The method depends on the extent to which the iodine-azide reaction has been catalysed by sulphide, and this is measured by titration of the amount of iodine consumed in a fixed time period. 相似文献
13.
The stoichiometry of the oxidation of rhamnose by periodate has been studied using a method based on the determination of iodate. Conditions have been found under which one mole of rhamnose stoichiometrically reduces six moles of periodate. An amplification method for the titrimetric determination of rhamnose is proposed in which one mole of rhamnose reacts with 6 moles of periodate with the formation of six moles of iodate, which is equivalent to 18 moles of triiodide, in the titration of which 36 gram-equivalents of sodium thiosulfate are consumed. The method is distinguished by high sensitivity and accuracy. The relative standard deviation in the determination of 2–3.5 mg of rhamnose does not exceed 0.5–1%.Biokhimreaktiv Scientific Production Association. All-Union Scientific-Research Institute of Applied Biochemistry, Olaine. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 21–24, January–February, 1984. 相似文献
14.
V. R. Casella C. T. Bishop A. A. Glosby C. A. Phillips 《Journal of Radioanalytical and Nuclear Chemistry》1981,62(1-2):257-266
A radiochemical procedure is presented for the sequential determination of uranium isotopes, thorium isotopes, and210Pb in coal and coal ash. This procedure consists of dry ashing the sample, a nitric—hydrofluoric acid dissolution, removal
of iron with ether extractions, and separation of the elements of interest by anion exchange chromatography. Uranium and thorium
isotopes are measured by alpha spectrometry, while210Pb is measured by beta counting its daugther activity,210Bi. For 10 g coal samples and 1 g ash samples, the chemical yields for the radioactivities measured were 70–80%, and the relative
standard deviations for replicate analyses were generally less than 9%. The deviations of the means from the reference values
were within the combined errors of each and were usually less than ±5%. Minimum detectable activities were about 0.02 pCi
for uranium and thorium isotopes and 0.2 pCi for210Pb. 相似文献
15.
A method is described for the determination of neptunium and plutonium in process solutions. This involves the separation
of these elements followed by their spectrophotometric determination as Arsenazo III complexes. Neptunium(IV) and plutonium(IV)
are separated using TTA extraction method and the separated Np(IV) and Pu(IV) are then determined as their Arzenazo III complexes
in 5M HNO3. A few solutions obtained by dissolving irradiated fuels were analysed for plutonium and neptunium using this method and
the results were compared with those obtained by other methods. An attempt was made to use Arsenazo III to determine uranium
in the plant solutions. 相似文献
16.
J. M. Godoy M. L. Godoy Z. L. Carvalho 《Journal of Radioanalytical and Nuclear Chemistry》1995,200(6):545-550
A so-called hour method for the determination of plutonium based on extraction chromatography is validated by its application to several certified soil and sediment samples from the International Atomic Energy Agency's Seibersdorf Laboratory. The results are in good agreement with the reference values. Chemical yields range between 47%–66%, with a mean value of (56±6)%. The possible use of this method for241Pu determination is also demonstrated. 相似文献
17.
G. R. Relan A. N. Dubey S. Vaidyanathan 《Journal of Radioanalytical and Nuclear Chemistry》1996,204(1):15-22
A ratio derivative spectrophotometric method has been developed for the simultaneous determination of uranium and plutonium at mg levels in 1M HNO3 medium. In this method the overlapping spectra of uranium and plutonium are well resolved by making use of the first derivative of the ratios of their direct absorption spectra. The derivative ratio absorbances of uranium and plutonium are measured at 411.2 and 473.8 nm, respectively for their quantification. The method is simple, fast and does not require separation of uranium and plutonium. Another salient feature of the method is that it does not lead to generation of analytical waste thereby minimising the efforts required for the recovery of plutonium. Uranium in the conc. range of 10–25 mg/g and plutonium in the conc. range of 0.5 to 2 mg/g (U/Pu ratio varying from about 10 to 25) were determined in the same aliquot with a precision and accuracy of about 0.5% and 1%, respectively. 相似文献
18.
A highly precise method is described for the determination of plutonium by constant-current potentiometric titration with primary standard potassium dichromate. The relative standard deviation is 0.04% or better. 相似文献
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J. Krtil F. Sus V. Bulovič E. Klosová 《Journal of Radioanalytical and Nuclear Chemistry》1980,58(1-2):83-88
A modified radiometric method for the determination of plutonium in irradiated nuclear fuel is described. The analysis consists
of total plutonium alpha-activity, activity ratio238Pu:(239Pu+240Pu) and burnup determination. The error of plutonium determination is practically identical with that of a classical radiometric
method. The method suggested is suitable for large sample series of the same type of irradiated nuclear fuel. 相似文献