Preparation of samarium-153-EDTMP and determination of its radiochemical purity using paper chromatography

Samarium-153-ethylenediaminetetramethylenephosphonate (¹⁵³Sm-EDTMP) has been used to palliate pain resulting from bone cancer. This paper describes the preparation of¹⁵³SmCl₃ from irradiated natural samarium and the ability of¹⁵³Sm to complex with EDTMP in liquid and in freeze-dried forms. The evaluation of radiolabeled EDTMP was done by paper chromatography. A rapid evaluation of free¹⁵³SmCl₃ and¹⁵³Sm-EDTMP was developed using a miniaturized chromatographic system.     

Determination of rare earths in silicate rocks by epithermal neutron activation and a simple group separation

The determination of nine rare earth elements in rock samples by epithermal neutron activation, followed by a simple group-separation procedure and Ge(Li) γ-ray spectrometry, is described. This method is found to be advantageous for the determination of Nd, Gd, Ho, Er and Lu by means of the short-lived nuclides¹⁴⁹Nd,¹⁵⁹Gd,¹⁶⁶Ho,¹⁷¹Er and^176m Lu. Precision for La, Sm and Eu is similar to that of thermal neutron activation, that for Dy is worse. Samples of the standard rocks, basalt BCR-1 and granite G-2, were analyzed by this procedure and the results obtained are compared with previously reported data.     

Determination of crossed-second-order field shift in8 F and6 F terms of 4f 6(7 F)6s configuration of sm+

We report here the experimental evaluation of crossed-second-order (CSO) effects in the field shift of⁸ F and⁶ F terms of 4f ⁶(⁷ F)6s configuration of singly ionised samarium. Our experimental value of CSO field shift difference between⁸ F and⁶ F terms for¹⁴⁸Sm and¹⁵⁴Sm is ?11.8(3.2) mK, which is in good agreement with the theoretical value of ?13.8 mK evaluated using known parameters.     

Determination of Samarium in rocks by epithermal neutron-activation analysis

Summary A non-destructive neutron-activation method for the determination of samarium in rocks, based on activation with epithermal neutrons, is described. By this means the formation of¹⁵³Sm, as compared to most interfering radionuclides, is considerably higher than by thermal neutron activation. The precision of the method is 2–3% in the range of 3–25 ppm, and the sensivity is about 0,1 ppm. Results are presented for some standard rocks. The influence of other rare earth nuclides on the measurement of the 41 KeV X-ray of¹⁵³Sm has been investigated.

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Zerstörungsfreie Bestimmung von Samarium in Gesteinen durch Aktivierungsanalyse mit epithermischen Neutronen

Zusammenfassung Die Bildung von¹⁵³Sm ist hierbei im Vergleich zu den meisten störenden Radionukliden beträchtlich größer als bei der Aktivierung mit thermischen Neutronen. Die Präzision des Verfahrens beträgt 2–3% im Bereich von 3–25 ppm, die Empfindlichkeit etwa 0,1 ppm. Für einige Standardgesteine werden die Ergebnisse angeführt. Der Einfluß anderer Nuklide Seltener Erden auf die Messung der 41 keV Röntgenstrahlung von¹⁵³Sm wurde untersucht.

     

A direct carbon-13 and nitrogen-15 NMR study of samarium(III) complexation with nitrate and isothiocyanate in aqueous solvent mixtures

The extent of inner-shell, contact ion-pairing between samarium(III)-nitrate and in a preliminary manner, samarium(III)-isothiocyanate, has been determined by a direct, low-temperature, multinuclear magnetic resonance technique. In water-acetone mixtures containing Freon-12 or Freon-22, the slow exchange condition is achieved at –110 to –120°C, permitting the observation of¹⁵N NMR resonance signals for bulk and coordinated nitrate. In these mixtures, signals are observed for Sm(NO₃)²⁺, Sm(NO₃) ₂ ⁺ , and two higher complexes, possibly the tetranitrato with either the penta-or hexanitrato.¹H NMR signals for bound water molecules in these mixtures were observed, but accurate hydration numbers can not yed be determined. In anhydrous or aqueous methanol mixtures,¹⁵N NMR signals for only three complexes are observed, with the dinitrato clearly dominating. Using¹⁵N and³⁵Cl NMR chemical shift and linewidth measurements, the superior complexing ability of nitrate compared to perchlorate and chloride, was demonstrated. Successful preliminary¹³C and¹⁵N NMR measurements of Sm³⁺-NCS^– interactions in water-acetone-Freon-22 mixtures also have been made. The¹³C NMR spectra reveal signals for five complexes, presumably Sm(NCS)²⁺ through Sm(NCS) ₅ ^2– . In the¹⁵N NMR spectra, signals for only three complexes are observed (the result of insufficient spectral resolution.) displaced about +240 ppm from bulk anion.     

Background levels of238U and226Ra in atmospheric aerosols

The²³⁸U and²²⁶Ra contents of small-volume aerosols are determined by a chemical analysis technique. Mean activity concentrations of²³⁸U and²²⁶Ra in aerosols over approximately ten years are 0.29·10^–5 and 0.93·10^–5 Bq/m³, respectively. The yearly variation of²³⁸U and²²⁶Ra in aerosols is small. The concentrations of²²⁶Ra are always larger than those of²³⁸U in the same sampling time. The correlation of²³⁸U and²²⁶Ra cannot be recogonized (r=0.18). The concentrations of summer samples are greater than those of winter samples for²³⁸U. One of the causes of seasonal difference may be due to the fact that the components of aerosols are different according to soil size, soil components, weathering states, etc.     

Low level measurements of129I in environmental samples

An analytical method for the determination of¹²⁷I and¹²⁹I in various environemntal samples has been developed. The method consists of the separation of iodine from the samples using a double layered quartz tube firing apparatus, post-irradiation purification of iodine, and measuring¹²⁶I and¹³⁰I by means of gamma spectrometry. The relative standard deviations of this method was less than 6%.     

The use of photon activation analysis for the determination of Sm,Eu, Gd and Dy in boron carbide

An installation for photon activation analysis recently completed at CBNM, Geel, is described. Synthetic standards prepared from pure graphite are used for the non-destructive determination of lanthanides in boron carbide. The induced activities of¹⁵³Sm,^152mEu,¹⁵⁹Gd and¹⁵⁷Dy were measured using a single open-ended coaxial Ge(Li) detector and the photopeak areas were calculated using the GAFIT program. For the irradiation parameters used, the limits of detection are communicated. This paper has been presented at the 5th Symposium on the Recent Developments in Activation Analysis. 17th–21st July, 1978, St. Catherine's College, Oxford.     

89Sr/90Sr-Determination in soils and sediments using crown ethers for Ca/Sr-separation

A radiochemical procedure is described for the sensitive determination of⁸⁹Sr and⁹⁰Sr activity concentrations in soil and sediment samples. After leaching the sample with hydrochloric acid, Sr is separated from most of the soluble matrix constituents and Ca by solvent extraction using dicylclohexano-18-crown-6 in trichloromethane. After backextraction with a EDTA-solution (ethylene diamine tetra acetate), Sr is purified by several precipitation steps from traces of matrix constituents and radionuclides which might interfere the beta measurements of⁸⁹Sr,⁹⁰Sr and⁹⁰Y. The detection limits are about 0.2 Bq/kg and 0.4 Bq/kg for⁹⁰Sr and⁸⁹Sr respectively. The procedure can be applied to all kind of environmental samples with small modifications of the sample preparation steps prior to analysis.     

Determination of low level85Kr and133Xe concentrations in the environment

This study was performed under the joint TRMC/INER program for the determination of low level⁸⁵Kr and¹³³Xe concentrations in the environmental air samples. Based on cryogenic adsorption of krypton and xenon on charcoal followed by chromatographic separation from other gases, the⁸⁵Kr and¹³³Xe recovered from 200 liters of atmospheric air can be determined by either on-line gas flow proportional counter or liquid scintillation counting. The recovery yields of krypton and xenon examined by using⁸⁵Kr and¹³³Xe tracers were nearly 100%. The minimum detectable activity of⁸⁵Kr and¹³³Xe by gas flow proportional counting is about 7.40 Bq. The method is satisfactory for environmental monitoring applications under abnormal conditions of nuclear facilities. However, for lower level environmental⁸⁵Kr and¹³³Xe measurements, the liquid scintillation counting method can be applied due to their extremely low detection limits (i.e. 0.107 Bq and 0.093 Bq for⁸⁵Kr and¹³³Xe, respectively). Using this method, the measurable limits of concentrations are 0.535 Bq/m³ and 0.466 Bq/m³ for⁸⁵Kr and¹³³Xe, respectively.     

New method for simultaneous determination of55Fe and59Fe in blood samples

A new simple method for the simultaneous determination of⁵⁹Fe and⁵⁵Fe concentration in 5 ml samples of blood is described and carefully evaluated. Before the measurement of the activity of the radionuclides, organic matter was eliminated by HNO₃?HClO₄ wet ashing. Iron was electroplated onto a copper plate. The accuracy of results was studied by assessing samples, which contained known amounts of radioactivity and determining the counts per nanocurie in each case. The accuracy of the results of⁵⁹Fe and⁵⁵Fe determinations was found to be about 5%.     

Determination of trace elements in carbonates by instrumental neutron activation analysis

A systematic non-destructive determination of eighteen trace elements (F, Na, Cl, Sc, Mn, Zn, Br, Sr, I, Ba, La, Ce, Sm, Eu, Tb, Yb, Th and U) in carbonate samples by thermal neutron activation analysis was developed. Three 0.2–0.5g samples were irradiated for 15 sec (in the case of determination of F), for 3 min (in the case of Na, Cl, Mn, Sr and I) and for 60 hrs (in the case of Sc, Zn, Br, Ba, La, Ce, Sm, Eu, Tb, Yb, Th and U) in the TRIGA MARK II Reactor at a thermal neutron flux of 5·10¹¹ n·cm⁻²·sec⁻¹ (15 sec and 3 min irradiation) and 1.5·10¹²n·cm⁻²·sec⁻¹ (60 hrs irradiation), respectively. According to the half life of the nuclides formed, the activities were measured with a Ge(Li) spectrometer as follows,²⁰F∶15 sec counting after 20–25 sec cooling,²⁴Na,³⁸Cl,⁵⁶Mn,^87mSr and¹²⁸I∶600 sec couting after 30–120 min cooling,⁸²Br,¹⁴⁰La,¹⁵³Sm,¹⁷⁵Yb and²³⁹Np (daughter of²³⁹U)∶3000 sec counting after 1 week cooling,⁴⁶Sc,⁶⁵Zn,¹³¹Ba,¹⁴¹Ce,¹⁵²Eu,¹⁶⁰Tb and²³³Pa (daughter of²³³Th)∶5000 sec counting after 1 month cooling. The errors due to the fluctuation of the neutron flux and the counting geometry were minimized by the use of calcium determined previously with EDTA-titration as an internal standard. The interferences from²⁴Mg(n, p)²⁴Na and²³⁵U(n, fission) reactions were corrected by the activities produced by the reactions in unit weight of magnesium and uranium, and their concentrations in samples measured experimentally. The data of Na, Mn, Zn and Sr were compared with the results obtained by atomic absorption analysis.     

Determination of137Cs and90Sr in milk by the static method with an ion exchanger

This paper presents the method of⁹⁰Sr and¹³⁷Cs determination from 10 litres of milk. The preconcentration is made by the static method with a strong acid cation exchanger (OSTION KS).¹³⁷Cs from the eluent (8M HCl) is selectively eliminated with ammonium molybdophosphate and then the^137mBa gamma activity measured, using NaI(T1) detector.⁹⁰Sr as⁹⁰Y is determined after achievement of the radioactive equilibrium and measured by flow proportional counter. The method appears to be accurate, reproducible and permits to determine³² mBq¹³⁷Cs and 13 mBq⁹⁰Sr in the samples.     

Simultaneous determination of210Bi and210Po on pine needles by solvent extraction and liquid scintillation counting

A determination procedure has been developed for²¹⁰Bi and²¹⁰Po in environmental samples and was applied for pine needles. Bismuth-210 and²¹⁰Po separated from the parent nuclide²¹⁰Pb as BiOCl precipitate were extracted simultaneously by TOPO/toluene containing PPO and POPOP. The separation of²¹⁰Bi and²¹⁰Po from²¹⁰Pb was almost satisfactory. The activity of²¹⁰Bi+²¹⁰Po in the TOPO/toluene was measured periodically by liquid scintillation counting for about 20 days after separation. The time course of the decreasing pattern of the activity was determined by the initial activity ratio²¹⁰Po/²¹⁰Bi. The decreasing pattern of the activity was compared with theoretical patterns, and best estimates for²¹⁰Po and²¹⁰Bi were obtained by non-linear least-squares fitting. The activities of²¹⁰Bi and²¹⁰Po were determined for one-year and two-year old pine needles fro the same pine tree, and weathering half-time and deposition rate of these nuclides was discussed.     

A gamma-spectrometric method for the determination of plutonium isotope ratios

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.     

The stability of99mTc phosphorus compounds in plasma both in vivo and in vitro

The in vivo and in vitro stability of^99mTc hydroxyethlylidene diphosphonate, 99^mTc methylenediphosphonate and^99mTc pyrophosphate in plasma has been studied using paper chromatographic technique as the analytical tool. The results indicate that the amounts of^99mTc activity found both at the origin and R_f range of^99mTcO₄ ^? for in vivo experiments are slightly greater than those for either in vitro or control experiments. However, this amount of^99mTc activity represents about 0.16–0.4% of the injected dose. Therefore, it is suggested that^99mTc phosphorus radiopharmaceuticals are stable in vivo and neither oxidation nor hydrolysis of these bone imaging agents occurs in the blood.     

Determination of228Th,230Th,and232Th in environmental samples from uranium mining and milling operations

A method is described for the determination of²²⁸Th,²³⁰Th, and²³²Th in environmental samples from uranium mining and milling operations. The analytical procedure is based on the direct determination of²²⁸Th in the sample by high resolution γ-spectrometry followed by extraction and purification of the thorium fraction using high molecular weight amines and an anion-exchange technique, respectively, prior to α-spectrometry to determine isotopic ratios. The lowest level of detection for each thorium isotope is 0.01 pCi/g for solid samples and 20 pCi/l for aqueous samples. Replicate analyses of a typical mine waste stream gave a standard deviation of ±3% for²²⁸Th. Standard deviations of the²³⁰Th and²³²Th increased to ±11% apparently due to traces of²¹⁰Po interfering in the α-spectrometry.     

An improved apparatus for the determination of krypton-85 and xenon-133 in an emergency situation

A simple and portable apparatus was developed for measurements of⁸⁵Kr and¹³³Xe that would be released into the atmosphere in an emergency situation of nuclear facilities. The method is based on cryogenic adsorption of these gases on charcoal followed by chromatographic separation from other gases. The⁸⁵Kr and¹³³Xe recovered from atmospheric air are determined separately by liquid scintillation counting. It takes about 1 hour for the stepwise determination of⁸⁵Kr and¹³³Xe. The atmospheric concentration of 3·10^–3 Ci per m³ air (1.1·10² Bq/m³ air) is measurable for both nuclides with 20% counting error.     

A method for the simultaneous estimation of228Th and229Th

A simple method is reported in this paper to estimate²²⁹Th in the presence of²²⁸Th. The total activity of²²⁹Th and²²⁸Th was determined by following the alpha activity growth (using a liquid scintillation counter and proportional counter) of purified thorium samples. The activity ratio of²²⁹Th/²²⁸Th was determined by alpha spectrometry. From the initial total activity and ratio, disintegration rates of²²⁹Th and²²⁸Th were calculated. The values obtained for the activities have a precision better than ±2%.     

Preparation of99mTc complexes with compounds structurally related to ethylene diamine tetraacetic acid

The preparation of^99mTc-Sn-DOTA,^99mTc-Sn-DDDTA and^99mTc-Sn-DHDTA is described. The labelling efficiency of all samples was checked by paper chromatography, thin layer chromatography and paper electrophoresis. Preliminary results of the biodistribution studies performed in white rats are given.