Radiochemical separation of antimony and tellurium in isotope production and in radionuclide generators

A potentially useful radionuclide generator for PET studies is based on ¹¹⁸Te/¹¹⁸Sb. A novel single-step approach using anion-exchange chromatography was developed to separate the ¹¹⁸Te parent activity from proton-irradiated targets. The average yield of radiotellurium using this method was 88%, with no detectable radioantimony contamination. A generator system employing activated carbon as a column chromatography adsorbent was studied. An ¹¹⁸Sb elution yield of 87%, with a radiotellurium breakthrough of less than 0.1%/ml, was achieved. Oxidation state studies indicate that approximately 39% of the ¹¹⁸Sb formed in the decay of ¹¹⁸Te is in the form of Sb(V). Details of these separations are presented. This revised version was published online in July 2006 with corrections to the Cover Date.     

Distribution of gamma radionuclidic impurities in routine99mTc generator eluates

Fission-produced -emitting radionuclidic impurities in eluates obtained by elution of routine (n,f)⁹⁹Mo/^99mTc generators have been determined. Four radionuclidic impurities were identified and quantitatively measured by the method of -spectrometry. The distribution of¹⁰³Ru,¹⁰⁶Ru,¹²⁵Sb and¹³¹I in the eluates was followed. The fraction of the activity which has been desorbed from alumina in the generator column during the lifetime of the generator was determined for earch radionuclide found. The contents of radionuclidic impurities in the eluates were compared with the criteria of radionuclidic purity prescribed by the Pharmacopoeia.     

An oblique section hydride generator for the simultaneous determination of arsenic, antimony and bismuth in geological samples by inductively coupled plasma-atomic emission spectrometry

Summary An oblique section hydride generator is developed for use in combination with inductively coupled plasmaatomic emission spectrometry. The generator offers less interferences from concomitant ions and transition metal ions when compared with the conventional hydride generators reported in literature. The emission signals and the detection limits of the analytes are also improved. The recommended hydride generator has been applied to the determination of arsenic at g/g level and antimony and bismuth at subg/g level in geological standard reference materials. A good agreement is achieved between the data obtained by the present study and the certified values.

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Abgeschrägter Hydridgenerator für die Simultanbestimmung von As, Sb und Bi in geologischen Proben durch ICP-AES

     

Selective determination of antimony(III) and antimony(V) in liver tissue by microwave-assisted mineralization and hydride generation atomic absorption spectrometry

Antimony(III) and antimony(V) species have been selectively determined in liver tissues by optimizing the acidic conditions for the evolution of stibine using the reduction with sodium borohydride. The results show that a response for Sb(III) of 0.5 to 20 g l^–1 was selectively obtained from samples in a 1 mol l_–1 acetic acid medium. The best response for total antimony from 1 to 20 g l^–1 is obtained after sample treatment with a 0.5 mol l^–1 sulfuric acid and 10% w/v potassium iodide. Microwave digestion has been necessary to release quantitatively antimony species from sample slurries. The amount of Sb(V) was calculated from the difference between the value for total antimony and Sb(III) concentrations. A relative standard deviation from 2.9 to 3.1% and a detection limit of 0.15 and 0.10 g l^–1 for Sb(III) and total Sb has been obtained. The average accuracy exceeded 95% in all cases comparing the results obtained from recovery studies, electrothermal atomic absorption spectrometry and the analysis of certified reference materials.Dedicated to Professor Dr. Peter Brätter on the occasion of his 60th birthday     

Proton-activation technique for the determination of antimony

Proton-activation analysis has been applied to the determination of antimony. Thick-target yields and analytical sensitivities are given for the indicator-radionuclides (119m)Te, (119g)Te, (121m)Te, (121g)Te, (123m)Te, (120m)Sb and (122g)Sb for proton energies between 9 and 25 MeV. In irradiations with a 5-muA beam for 5 hr, followed by a specific separation of the indicator-radionuclides, limits of detection at the ppM level can be achieved. Data are given for the most significant interfering reactions. Antimony was determined instrumentally in bismuth of "very pure" grade and the results are compared with those obtained from two independent techniques.     

Separation of trace elements,In(III), Sn(IV), Sb(V) and Te(IV) by adsorption on activated carbon and graphite

Adsorption behaviour of trace elements, In(III), Sn(IV), Sb(V) and Te(IV) on activated carbon and graphite powder was studied. Adsorption characteristics of the ions enabled the separation of In(III)–Sn(IV), Sn(IV)–Sb(V) and Sb(V)–Te(IV) pairs. Applications to practical separation, milking of^113mIn from¹¹³Sn, removal of tin impurity from¹¹⁹Sb, and milking of¹¹⁹Sb from^119mTe, are presented.     

Mössbauer study of defect119Sn atoms with ligands from silver to iodine

Mössbauer emission spectra of defect¹¹⁹Sn atoms arising from¹¹⁹Sb were measured in InSb, GaSb, CdSb, ZnSb, In₂Te₃, CdTe, and Ag₂Te labeled with¹¹⁹Sb or its parent^119mTe. Together with the results of our previous studies, the isomer shifts of defect and normal¹¹⁹Sn were shown to correlate with the electronegativity of ligands from silver to iodine.     

Aufnahme von Spurenmengen Antimon (Radioantimon) durch einige Metalloxidhydrat-Niederschläge

Zusammenfassung Mit trägerfreiem¹²⁵Sb bzw. trägerarmem¹²⁴Sb wurde die Aufnahme von Spurenmengen Antimon(III) durch Fe(III)-, Al-, Zr- und Ti-Oxidhydrat untersucht. Für die Aufnahme von Antimon durch Mitfällung wurde gefunden: ZrTi>Fe Al. Bei Mitfällung aus 1M-NaCl und bei pH 7 sind etwa folgende Metallionenmengen erforderlich, um Antimon zur Hälfte mitzufällen: Zr oder Ti 0,02 mMol/l, Fe 0,1 mMol/l bzw. Al 3 mMol/l. Bei Fe-, Zr- und Ti-Oxidhydrat beträgt die Radioantimonaufnahme durch Mitfällung das 5- bis 8fache der Aufnahme durch Sorption an vorgebildeten Niederschlägen. Bei Mitfällung überwiegt daher hier Einbau in das Innere des Niederschlags sehr stark gegenüber Adsorption an der Oberfläche. Versuche mit Radiostrontium (trägerarmem⁸⁵Sr) ergeben im Gegensatz hierzu, daß bei Fe-, Al- und Ti-Oxidhydrat Mitfällung und Sorption an vorgebildeten Niederschlägen zu ungefähr gleich starker Aufnahme führen. Ferner wurde die Abhängigkeit der Radioantimonaufnahme vom pH und von der NaCl-Konzentration der Lösungen ermittelt und daraus Schlüsse auf die Natur des Aufnahmeprozesses gezogen.

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Uptake of trace amounts of antimony (radioantimony) by precipitates of some hydrated metal oxides

Uptake of trace amounts of antimony(III) by the hydrated oxides of Fe(III), Al, Zr and Ti was investigated using carrier-free¹²⁵Sb or¹²⁴Sb of high specific activity. For uptake of antimony by coprecipitation, the following order was found: ZrTi>FeAl. The amounts of metal ions required to coprecipitate half of the antimony from 1M-NaCl at pH 7 are: Zr or Ti-0.02 mMol/l, Fe-0.1 mMol/l, Al-3 mMol/l. With the hydrated oxides of Fe, Zr and Ti, uptake of radioantimony by coprecipitation is 5 to 8 times as great as uptake by sorption on preformed precipitates. In coprecipitation, incorporation into the interior of these precipitates thus exceeds adsorption on the surfaces considerably. In contrast, experiments with radiostrontium (⁸⁵Sr of high specific activity) have shown that for the hydrated oxides of Fe, Al and Ti uptake by sorption on preformed precipitates is about equal to that by coprecipitation. Dependance of uptake of radioantimony upon pH and concentration of NaCl was also determined and conclusions regarding the nature of the processes responsible for uptake were drawn.

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Mit 7 Abbildungen

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FürE. B. (Univ.-Prof. Dr.Engelbert Broda) mit herzlichen Wünschen zum 60. Geburtstag.     

The anion exchange behavior of Te and Sb

The absorption behavior of Te and Sb in different oxidation states by anion exchange resins in hydrochloric acid medium has been studied. Distribution coefficients for Te(IV), Te(VI) as a function of HCl acid concentration (upto 3M HCl) have been determined. The absorbability for Sb(III) was noticed to be very high and could not be eluted out of the column using HCl as eluent. Sb(V) could be eluted quantitatively using 3M HCl. The present study clearly indicate that due to the EC/β⁺ decay of the parent isotopes^117,118Te, the daughter nuclei^117,118Sb are produced predominantly as Sb(III).     

Application of the photoionization detector for single determinations of hydride forming elements

The application of a photoionization detector in conjunction with a flow-through system is described for the determination of arsenic, antimony, selenium, tellurium, bismuth, tin, sulfide and ammonia. The analytical procedure is based upon a preliminary generation of the hydride compounds, their subsequent transfer to the gas phase and finally their detection in the photoionization detector. Linear calibration curves were obtained over three to four orders of magnitude with the following 3s-detection limits: 4 ng/ml As, 0.3 ng/ml Sb, 0.5 ng/ml Se, 3.0 ng/ml Te, 0.1 g/ml Bi, 0.5 g/ml Sn, 10.0 ng/ml S^2–, 0.5 g/ml NH₃.     

Isomeric yields of130Sb,132Sb,134I,and136I in the thermal neutron fission of235U

Isomer yield ratios of¹³⁰Sb,¹³²Sb,¹³⁴I and¹³⁶I isomers formed in the thermal neutron fission of²³⁵U have been calculated from our previous experimental studies that led to the identification of these species. In those studies the iodine and antimony fractions formed in fission were rapidly separated and the decay of -rays belonging to each isomer pair were followed using Ge(Li) detectors and a multichannel analyzer. The isomer ratios were calculated from growth and decay considerations of these -rays. The results are compared with the recently published values obtained with an on-line isotope separator, those from LOHENGRIN, and those from model calculations. Angular momenta of fission fragments corresponding to the measured isomer yields have also been calculated.     

Simultaneous determination of some long-lived semivolatile radionuclides in environmental samples

A radiochemical method is presented to determine simultaneously the long-lived semivolatile radionuclides⁷⁹Se,⁹⁹Tc,¹⁰⁶Ru,¹²⁵Sb,^125mTe,^127mTe,¹³⁴Cs and¹³⁷Cs in environmental samples. The pure -emitters⁷⁹Se and⁹⁹Tc are counted in a low-level gas flow counter, the -emitters in a -spectrometer with a high purity well-type Ge detector. The procedure was tested using environmental samples with known concentrations of⁹⁹Tc,¹⁰⁶Ru,¹²⁵Sb,¹³⁴Cs and¹³⁷Cs.     

Sorption and separation of some elements of nuclear importance using Chelex-100

Chelex-100, in the anionic form has been studied for its ability to perform selective separation and concentration of some metal ions of nuclear importance from mineral acid solutions. The sorption behavior of Zr(IV)–Nb(V), Mo(VI), Tc(VII), Te(IV) and U(VI) from solutions of hydrochloric and sulphuric acids on Chelex-100 has been studied under static and dynamic conditions. Mo(VI) and Tc(VII) have been concentrated on the resin from hydrochloric or sulphuric acid solutions at low acidities probably, as the anions MoO ₄ ^2– and TcO ₄ ^– , respectively. Te(IV) has been isolated from hydrochloric acid solutions of normalities 6 in the form of the anionic chloro complex TeCl ₆ ^2– . Optimum conditions for elution and separation of Mo(VI), Tc(VII), Te(IV) and U(VI) were recommended.     

Tetraphenylantimony <Emphasis Type="Italic">N</Emphasis>-benzoylglycinate: synthesis and structure

Tetraphenylantimony N-benzoylglycinate (I) has been synthesized by the reaction between pentaphenylantimony and N-benzoylglycine in toluene. According to X-ray diffraction data, the antimony atom in a molecule of complex I has a trigonal bipyramidal coordination to the oxygen atom in axial position. The Sb?C_eq, Sb?C_ax, and Sb?O bond lengths are 2.116(6)?2.138(6), 2.183(6), and 2.200(4) Å, respectively. The intramolecular Sb?O=C distance between the carbonyl oxygen atom and the central antimony atom is 3.35(2) Å.     

Speciation and preconcentration of inorganic antimony in waters by Duolite GT-73 microcolumn and determination by segmented flow injection-hydride generation atomic absorption spectrometry (SFI-HGAAS)

A selective matrix removal/separation/enrichment method, utilizing a microcolumn of a chelating resin with SH functional groups (Duolite GT-73), was proposed for the determination of Sb(III) in waters by segmented flow injection-hydride generation atomic absorption spectrometry (SFI-HGAAS). The resin was selective to Sb(III) at almost all pH and acidity values employed, whereas Sb(V) was not retained at all and could be determined after a pre-reduction step with l-cysteine. Spike recoveries were tested at various concentration levels in different water types and were found to vary between 85 and 118%. Accuracy of the proposed methodology was checked by analyzing a standard reference material and a good correlation was found between the determined (13.3 ± 1.1 μg l⁻¹) and the certified value (13.79 ± 0.42 μg l⁻¹). The method was applied to several bottled drinking water samples for antimony determination with and without preconcentration and none of the samples were found to contain antimony above the permissible level (5 μg l⁻¹). The characteristic concentration (the concentration of the analyte corresponding to an absorbance of 0.0044) was 0.55 μg l⁻¹ and the 3 s limit of detection (LOD) based on five times preconcentration was 0.06 μg l⁻¹. The applicability of the microcolumn separation/preconcentration/matrix removal method for flow injection systems was also demonstrated.     

Etude des generateurs d'indium-113m

Methods are proposed for the determination of¹¹³Sn in the eluate of an^113mIn generator as well as for the analysis of its chemical and radionuclidic purity. Two generators of different origin have been studied. The presence of the radioisotopes¹¹³Sn,¹²⁵Sb,^125mTe and the elements Zr, Si and Fe have been found in the eluate. Recommendations are given for the use of such generators.     

μ<Subscript>2</Subscript>-Oxobis[(aroxo)tris(<Emphasis Type="Italic">para</Emphasis>-tolyl)antimony]: Synthesis and Structure

µ₂-Oxobis[(2,4,6-tribromophenoxo)tris(para-tolyl)antimony] (I), µ₂-oxobis[(2,3,4,5,6-pentachlorophenoxo) tris(para-tolyl)antimony] (II), and µ₂-oxobis(2,4-dinitrophenoxo)tris(para-tolyl)antimony] (III) have been synthesized with high yields by the reaction of tris(para-tolyl)antimony with 2,4,6-tribromo-, 2,3,4,5,6-pentachloro-, and 2,4-dinitrophenol, respectively, in ether in the presence of tert-butylhydroperoxide. The Sb atoms in complexes I, II, and III have a distorted trigonal bipyramidal coordination with the aroxyl ligands and the bridging oxygen atom in axial positions. The central Sb–O–Sb moiety in molecules of complexes I–III has an angular structure.     

Application of ultrasonic-assisted cloud point extraction/flame atomic absorption spectrometry (UA-CPE/FAAS) for preconcentration and determination of low levels of antimony in some beverage samples

Due to be able to migrate or leach from food packaging materials into the foods and/or beverages, development of a new, sensitive and selective analytical methods for low levels of antimony as a food contaminant is of great importance in terms of food safety. In this context, an ultrasonic-assisted cloud point extraction method was developed for the preconcentration and determination of antimony as Sb(III) using 4-(2-thiazolylazo)resorcinol (TAR) and 2-(2-thiazolylazo)-p-cresol (TAC) as chelating agents and sodium dodecyl sulfate as signal enhancing agent at pH 6.0 and mediated by nonionic surfactant, t-octylphenoxypolyethoxyethanol by flame atomic absorption spectrometry. Using the optimized conditions, the calibration curves obtained from Sb(III) with TAR and TAC were linear in the concentration ranges of 0.5–180 and 1–180 μg L^?1 with detection limits of 0.13 and 0.28 μg L^?1, respectively. The precision (as relative standard deviations, RSDs) was lower than 3.9 % (25 and 100 μg L^?1, n: 6). The method accuracy was validated by the analysis of two standard reference materials. The results obtained were statistically in a good agreement with the certified values at 95 % confidence limit. The method has successfully been applied to the determination of Sb(III) and total Sb in selected beverages, milk and fruit-flavored milk products before and after pre-reduction of Sb(V) to Sb(III) with a mixture of KI/ascorbic acid in acidic media. The Sb(V) contents of samples were quantitatively calculated from analytical difference between total Sb and Sb(III) levels.     

Elemental distribution and thermoelectric properties of layered tellurides 39R-M(0.067)Sb(0.667)Te(0.266) (M=Ge, Sn)

The isostructural phases 39R‐Ge_0.067Sb_0.667Te_0.266 (R$\bar 3The isostructural phases 39R-Ge(0.067)Sb(0.667)Te(0.266) (R3m, a=4.2649(1), c=75.061(2) ?) and 39R-Sn(0.067)Sb(0.667)Te(0.266) (R3m, a=4.2959(1), c=75.392(2) ?) were prepared by quenching stoichiometric melts of the pure elements and subsequent annealing at moderate temperatures. Their structures are comparable to "superlattices" synthesized by layer-by-layer deposition onto a substrate. These structures show no stacking disorder by electron microscopy. The structure of the metastable layered phases are similar to that of 39R-Sb(10)Te(3) (equivalent to Sb(0.769)Te(0.231)), which contains four A7 gray-arsenic-type layers of antimony alternating with Sb(2)Te(3) slabs. Joint refinements on single-crystal diffraction data using synchrotron radiation at several K edges were performed to enhance the scattering contrast. These refinements show that the elemental distributions at some atom positions are disordered whereas otherwise the structures are long-range ordered. The variation of the elemental concentration correlates with the variation in interatomic distance. Z-contrast scanning transmission electron microscopy (HAADF-STEM) on 39R-Ge(0.067)Sb(0.667)Te(0.266) confirms the presence of concentration gradients. The carrier-type of the isostructural metal (A7-type lamellae)-semiconductor heterostructures (Ge/Sn-doped Sb(2)Te(3) slabs) varies from n-type (Ge(0.067)Sb(0.667)Te(0.266)) to p-type (Sn(0.067)Sb(0.667)Te(0.266)). Although the absolute values of the Seebeck coefficient reached about 50-70 μV/K and the electrical conductivity is relatively high, the two isotypic phases exhibit a maximal thermoelectric figure of merit (ZT) of 0.06 at 400 °C as their thermal conductivity (κ≈8-9.5 W/mK at 400 °C) lies interestingly in between that of antimony and pure Sb(2)Te(3).     

Übergangsmetall—Chalkogensysteme, 4. Mitt.: Die systeme Kobalt-Tellur und Kobalt-Nickel-Tellur

Zusammenfassung Das System Co–Te und einige Schnitte im System Co–Ni–Te wurden thermisch und röntgenographisch untersucht. Unter Berücksichtigung der Literaturdaten wurde das vollständige Co–Te-Phasendiagramm aufgestellt. Im Co–Te-System tritt in kobaltreichen Schmelzen eine Mischungslücke mit einer monotektischen Temperatur von 1460°C auf. Co und die hexagonale -Phase mit NiAs-Struktur bilden ein Eutektikum bei 48 At% Te und 980°C. Die -Phase hat einen kongruenten Schmelzpunkt von 1015°C bei 56,2 At% Te und einen maximalen Homogenitätsbereich von 55 At% Te bei 980°C bis 65 At% Te bei 970°C. Die -Phase vom Markasittyp ist zwischen 66,7 und 69,6 At% Te (bei 530°C) stabil und zersetzt sich peritektisch bei 764°C in eine Te-reiche Schmelze mit 89 At% Te und in die -Phase mit 63 At% Te. Mit Te bildet die -Phase ein entartetes Eutektikum bei 448,5°C. Für die -Phase wurden röntgenographisch die Gitterparameter in Abhängigkeit von der Konzentration vermessen.Im System Co–Ni–Te wurde der Homogenitätsbereich der NiAs-Phase thermisch mittels dreier Schnitte bei jeweils konstantem Te-Gehalt und mittels dreier Schnitte bei jeweils konstantem Co/Ni-Verhältnis untersucht. Die Liquidus- und Solidustemperaturen fallen kontinuierlich mit steigendem Ni-Gehalt, und die Legierungen sind im flüssigen und festen Zustand vollkommen mischbar. Die metallreiche Phasengrenze der NiAs-Phase verläuft bei 53–54 At% Te. Die Gitterparameter der ternären NiAs-Phase bei 55,5 At% Te folgen derVegardschen Regel.

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Transition metal—chalcogene Systems, IV: The Systems Co–Te and Co–Ni–Te

The system Co–Te and several sections of the system Co–Ni–Te have been investigated by thermal and X-ray analyses. With reference to data in literature the complete Co–Te phase diagram was constructed. Co-rich melts in the Co–Te system exhibit a miscibility gap with a monotectic temperature of 1460°C. Co and the hexagonal -phase with NiAs-structure form a eutectic at 48 at % Te and 980°C. The -phase has a congruent melting point of 1015°C at 56,2 at% Te and a maximum range of homogeneity from 55 at% Te at 980°C to 65 at% Te at970°C. The -phase with marcasite tructure is stable between 66,7 and 69,6 at% Te (at 530°C) and decomposes peritectically at 764°C into a Te-rich melt with 89 at% Te and the -phase with 63 at% Te. Te and the -phase form, a degenerate eutectic at 448,5°C. The lattice parameters of the -phase as a function of concentration were determined by X-ray analysis. In the ternary system Co–Ni–Te three sections at constant Te-content and three sections at constant Co/Ni ratio within the range of homogeneity of the NiAs-phase were investigated by thermal analysis. The liquidus and solidus temperatures drop continuously with increasing Ni content, and the alloys are completely miscible in the liquid and the solid state. The metal-rich phase boundary of the NiAs-phase is situated at 53–54 at% Te. The lattice parameters of the ternary NiAs-phase at 55,5 at% Te followVegard's rule.

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Mit 4 Abbildungen