The modified cyrogenic adsorption method for the laboratory separation of85Kr from the atmosphere

This paper decribes syntheses for the¹¹C-labelled chemotherapeutic drug, CCNU,¹¹C-labelled BFNU and CFNU (analogs of BCNU) as well as an improved synthesis for¹¹C-BCNU. Also discussed are procedures for the separation of dual isomers in the case of¹¹C-labelled CCNU and CFNU. The specific activity of these no-carrier-added radiopharmaceuticals was approximately 10⁴ lower than expected for a carrier-free product. The syntheses were normally finished 20–25 min after the end of the collection of¹¹C-COCl₂. Chemical and radiochemical purity of the final product, as determined by HPLC and TLRC respectively, was at least 98%. The syntheses yielded 10–25 mCi of nitrosourea ready for use in PET studies.To whom correspondance should be addressed at Medical Cyclotron Unit.     

Remote controlled unit for the production of [2-11C] isopropyl iodide

A remote controlled system is described for the production of [2-¹¹C] isopropyl iodide. The synthesis involves carbonation of methyl lithium with¹¹CO₂ followed by reduction with lithium aluminum hydride, hydrolysis and iodination with hydroiodic acid. The purification is performed by preparative gaschromatography on a Chromosorb 102-Porapak Q column. For a 30 min irradiation at 15 A beam intensity the method yields about 300 mCi /11 GBq/ of radiochemically and chemically pure [2-¹¹C] isopropyl iodide with a specific activity of 210 to 250 mCi. mol^–1 at the end of synthesis /EOB+25 min/. The remote controlled unit is also useful for the production of other alkyl iodides, acetone and acetic acid, labelled with¹¹C.     

Research for technique of preparing high-intensity241Am low-energy gamma-source

Systematically complicated technique used for preparing high-intensity (more than 8.0 GBq/cm²)²⁴¹Am -source by a new enamel technique is presented. High intensity²⁴¹Am -sources with activities ranging from 3.7 to 37 GBq have been made by this new technique. The activity and photon output have been measured. The results were compared with the data reported by the Radiochemical Centre Amersham in their specification. The photon output of²⁴¹Am -source produced by us meets the technical specification of²⁴¹Am -sources produced by Amersham. Moreover, the highest intensity can reach 1789 mCi/cm². The overall utilization ratio of²⁴¹Am activity (59.5 keV) is 31.2%.     

Production of123I using the CV-28 cyclotron at IPEN-CNEN/SP

These studies had the purpose of establishing the optimal conditions for the production of¹²³I through the¹²⁴Te (p, 2n)¹²³I reaction, using the CV-28 Cyclotron (E_max=24 MeV for protons) at IPEN-CNEN/SP. Two different targets (TeO₂ and TeO₂+2% Al₂O₃) were irradiated in order to check their physical resistance against beam current (up to 12 A) and length of irradiation (10 min — 2h), and to evaluate the recovery of the radioiodine produced, by a dry distillation process with a high frequency induction furnace. Later on, enriched¹²⁴TeO₂ (96.2%) targets were irradiated, and¹²³I was produced routinely with a production yield of (3. 31±0.07) mCi/Ah, 1.7% of¹²⁴I at EOB and radiochemically pure.     

The distribution coefficient of60Co in sediments from the Solway Firth, UK

The behaviour of⁶⁰Co in sea water and sediments typical of the Solway Firth has been investigated. The distribution coefficient,K _d, of⁶⁰Co²⁺ in sediments was determined using the batch sorption method and theK _d variation with aqueous phase composition, sediment type and pH has been studied. Adsorption of⁶⁰Co by sediments was found to be highest in de-ionised water and lower in NaCl solution (31 salinity). Adsorption was lowest in natural sea water, where theK _d range was 2,270 to 2,750. Variation ofK _d with sediment grain size was observed. It was shown that⁶⁰Co adsorption was strongly dependent on pH in de-ionised water, with less variation in NaCl solution. Variance of⁶⁰CoK _d values were lowest in sea water in the range pH 5–8 indicating a more conservative behaviour of⁶⁰Co than previously recognised. Hence⁶⁰Co dispersion will be predominantly govemed by tidal behaviour.     

The preparation and characterisation of chromium(III) complexes of C-meso-5, 12-dimethyl-1, 4, 8, 11-tetraazacyclotetradecane (LM). Aquation and base hydrolysis kinetics ofcis- andtrans-[CrLMCl2]+

Summary The reaction of [CrCl₃(DMF)₃] with C-meso-5, 12-dimethyl-1, 4, 8, 11-tetra-azacyclotetradecane(L_M) in DMF gives a mixture ofcis-[CrL_MCl₂]Cl (ca. 90%) andtrans-[CrL_MCl₂]Cl (ca. 10%). These complexes are readily separated, as thecis-isomer is insoluble in warm methanol while thetrans-isomer is soluble. Using the dichlorocomplexes as precursors it has been possible to prepare a range ofcis-[CrL_MX₂]⁺ complexes (X=Br^–, NO ₃ ^– , N ₃ ^– , NCS^– and X₂=bidentate oxalate) and alsotrans-[CrL_MX₂]⁺ complexes (X=Br^–, H₂O or NCS^–). The spectroscopic properties and detailed stereochemistry of the complexes are discussed.The aquation and base hydrolysis kinetics ofcis- andtrans-[CrL_MCl₂]⁺ have been studied at 25° C. Base hydrolysis of thecis-complex is extremely rapid with K_OH =1.46×10⁵ dm³ mol^–1 at 25° C. This unusual reactivity appears to be associated with thetrans II stereochemistry of thesec-NH centres of the macrocycle. Base hydrolysis of thetrans complex with thetrans III chiral nitrogen stereochemistry is quite normal with k_OH =1.1 dm³ mol^–1 s^–1 at 25° C.     

Physicochemical characterization of boro- and gallo-silicate isomorphs ofβ-zeolite

The crystalline isomorphs of-zeolite containing boron or gallium in the framework positions have been synthesized and the products characterized by comparing them with Al- zeolite. Evidence for the presence of B or Ga in the zeolite lattice framework has been confirmed by spectroscopic (XRD, IR and²⁹Si,²⁷Al and¹¹B MASNMR), DTA/TG, ion exchange, sorption and catalytic activity results. Chemical analysis and NMR confirm the absence of any significant amount of Al in the zeolite (SiO₂/Al₂O₃=2000). The XRD pattern of the as-synthesized B- and Ga- compounds matched well with that of Al- zeolite. Lattice B and Ga leads to a change in the X-rayd values. Framework and bridging hydroxyl stretching IR bands of-zeolite are shifted due to incorporation of gallium and boron into the zeolitic framework. MASNMR spectra of¹¹B and²⁹Si also suggest the presence of tetrahedrally coordinated B(III) or Ga(III) ions in the-zeolite framework. B and Ga-zeolites exhibit significant ion exchange capacity and catalytic activity in them-xylene isomerization reaction. The shifts in the IR bands towards higher frequency in B- and lower frequency in Ga-, the observed ion exchange capacities and catalytic properties, indicate the presence of B³⁺ or Ga³⁺ ions in the framework of-zeolite.     

Production of high specific activity <Superscript>68</Superscript>Ge at Brookhaven National Laboratory

Summary Germanium-68 is produced at the Brookhaven Linac Isotope Producer (BLIP) by irradiating ^natGa targets with ~45 MeV protons. Typical irradiation yields are 17.4 GBq (470 mCi) from a 4 week irradiation (0.52 MBq/µAh). Germanium-68 is recovered from the target by extraction into 4N HCl and 30% H₂O₂. Further purification is achieved by extraction into carbon tetrachloride and back-extraction into H₂O. Recovery yields are greater than 85%, with greater than 99% radiopurity, and activity concentrations are greater than 3.15 GBq/ml (85 mCi/ml). The final pH of the product solution, which is 0.03M diethylenetriaminepentaacetate (DTPA), can now be adjusted to user specifications.     

Synthesis of11C propranolol

A method is described by which 60 mCi¹¹C propranolol may be obtained from about 1 Ci¹¹CO₂ in 30 min without irradiation risk for personnel. The product is chromatographically pure, sterile and apyrogenic with a specific activity between 500 mCi and 2 Ci/μmole at the time of use. The synthesis involves the preparation of¹¹C acetone followed by fixation of the isopropyl group on the precursor [1-amino-3-(1-naphtyloxy)-2-propanol] by formation of an imine, then reduction of the latter by sodium cyanoboro hydride. The influence of certain parameters (reagents, precursor, impurities) on the final product is discussed.     

Metallobiochemistry of current environmental levels of trace metals: A new method of cyclotron production of48V for toxicological studies

No-carrier-added⁴⁸V at 37 Mbq (mCi) levels was produced at the JRC-Ispra cyclotron by (, n) reactions on a scandium target and used to label environmental and physiological levels of vanadium for metallobiochemical investigations. The radiochemical separation of⁴⁸V from Sc is very simple and rapid and involves a single chromatographic step after fast dissolution of the bombarded target. The yield of the separation and the radioisotopic purity of the separated⁴⁸V were nearly 100% A summary of the main results concerning different metabolic investigations on rats including absorption, retention, transfer of⁴⁸V from mothers to newborns, binding with enzymes as well as uptake by cell culture system is reported.At the time of this study visiting scientists at the^4,5Radiochemistry and³Functional Materials Divisions of the JRC-Ispra.     

Structure of lilidine

The new alkaloid lilidine, isolated for the first time from the epigeal part ofLilium martagon has been studied by special methods. It has the composition B₅H₆NO₂, mp 118–110°C, []_D-26.3°. The¹H and¹³C NMR spectra were studied in detail. The values of the direct and long-range spin-spin coupling constants between the¹³C carbon nuclei and the¹H nuclei of the alkaloid molecule were measured with the aid of¹³C-[{su1}H] selective heteronuclear double resonance. The structure of 5-hydroxy-3-methyl-3-pyrrolin-2-one is suggested for lilidine.Institute of the Chemistry of Plant Substances of the Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 692–696, September–October, 1987.     

Synthesis of deuterium and tritium labelled phenyl glycine

A new method of synthesis of phenyl glycine labelled with deuterium and tritium was elaborated. Labelled phenyl glycine was obtained by isotope exchange method between phenyl glycine and deuterated or tritiated water at elevated temperature in hydrochloric acid medium using K₂PtCl₄ as a catalyst. 37 GBq /1 Ci/ HTO was used for the synthesis of tritiated phenyl glycine and labelled product with specific activity of 185 MBq/mole /5 mCi/mole/ was obtained.     

Carrier-free separation of167Tm from Yb,Er and Ho targets by reversed-phase extraction chromatography and preparation for its medical use

Reversed-phase extraction chromatography employing a Daiflon-supported HDEHP column and HCl as eluent was examined for carrier-free separation of¹⁶⁷Tm from a photo-irradiated Yb target and also from particle-bombarded Er and Ho targets. The examination was performed with radioassays of radioactive Tm and Yb tracers and⁵⁷Co--induced X-ray analysis of Er and Ho. An example of the separation of about 1 mCi of¹⁶⁷Tm from a 100 mg irradiated Yb target enriched in¹⁶⁸Yb and a procedure for the final preparation for medical use are described. The YbSO₄ precipitation could be combined with this chromatographic separation of¹⁶⁷Tm from a more massive Yb target of natural abundance, weighing several tens of grams. A procedure for YbSO₄ precipitation is also presented in the Appendix.     

Preparation of carbon-11 labelled acetate and palmitic acid for the study of myocardial metabolism by emission-computerised axial tomography

Methods have been developed for the labelling of acetate and palmitic acid with the positron-emitting radionuclide,¹¹C (T=20.4 min). Labelling was achieved via carbonation of the appropriate alkyl magnesium bromide (methyl magnesium bromide or n-pentadecyl magnesium bromide) with¹¹C-labelled carbon dioxide produced by the¹⁴N(p, α)¹¹C nuclear reaction. The radiochemical yield and speed of each method of labelling are such that a radiochemically pure product is obtained in injectable form and in activity (>10 mCi) suitable for the study of myocardial metabolism by emission-computerised axial tomography. High pressure liquid chromatography and thin layer chromatography were used to assess the radiochemical purity of each radiopharmaceutical. The specific activity of¹¹C-labelled acetate was estimated by an enzymic procedure to be greater than 0.5 Ci/μmole.     

Synergistic extraction of manganese(II) with thenoyltrifluoroacetone and neutral unidentate and bidentate ligands

Tritium content in tritiated titanium was measured by the method of fluorescent X-ray detection with an intrinsic Ge detector. The conventional method of setting region-of-interest of overlapped X-ray peaks was developed. The Ti K and K X-ray peak profile of³H/Ti was compared with that of V-49 electron capture standard source. Effect of geometry and sample thickness on peak profile was discussed. Detection limit in this method was 0.187 GBq of tritium.     

Optisch aktive aromatische Spirane, 7. Mitt. Circulardichroismus optisch aktiver 5,5′-disubstituierter 2,2′-Spirobiindane

Dipole-dipole coupling of the indane fragments in 5,5-disubstituted 2,2-spirobiindanes is predominantly responsible for the origin of optical activity in the¹L_a-electronic transition only if both ligands exhibit strong interaction with the aromatic nuclei. This mechanism does not contribute essentially to the¹L_b-Cotton effect.The band-splittings of the couplet as well as the rotational strengths of the transitions ofA andB symmetry-type in the¹L_a-Cotton effect are in accordance with a rough calculatory estimation.The absolute configuration thus determined agrees with the chirality recently deduced by chemical methods.The rotational strengths of the¹W-Cotton effect of the carbonyl derivatives4, 5, 12, 13, and15 located at appr. 320 nm are remarkably low. This can be explained on the basis of conformational considerations.

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6. Mitt.:H. Neudeck undK. Schlögl, Chem. Ber.110. 2624 (1977).     

A rapid and accurate method for the determination of strontium-90 in environmental soil

A rapid and accurate method for the determination of⁹⁰Sr in environmental soil has been developed; the procedure includes soil leaching by hydrochloric acid, oxalate precipitation, decontamination from²¹⁰Bi, separation by HDEHP extraction chromatography column, yttrium oxalate precipitation and -counting. The interference of²¹⁰Bi was found and studies have been made for the decontamination of⁹⁰Y from²¹⁰Bi by Bi₂S₃ precipitation giving a decontamination factor of 1.05·10³. The analytical results obtained by the improved rapid method for 12 soil samples were comparable to that obtained by a previous method within a relative error of 20%. Studies of vertical distribution of⁹⁰Sr in an environmental soil profile have shown that 90% of the⁹⁰Sr deposits in the 30 cm surface soil of the earth with a highest concentration of 3.40 Bq/kg. When 50 g soil was analyzed, the yield of yttrium was 73±17% with a detection limit of 0.26 Bq/kg.     

Production of123I and28Mg by high-energy nuclear reactions for applications in life sciences

The advantages of high energy cyclotrons as compared to small compact cyclotrons for the production of special radionuclides are outlined. The routine production of¹²³I (T=13.3 h) and²⁸Mg (T=21.1 h) by means of high energy nuclear reactions at the Jülich Isochronous Cyclotron is described. The reaction¹²⁷I(d,6n)^{123 123}I at 78 to 64 MeV is used for the production of¹²³I with thick target yields of 8 mCi/μAh and high radionuclidic purity. The practical experience in the application of this process, which is well suited for the production of Na¹²³I and for¹²³Xe-exposure labelling techniques, is reported.²⁸Mg is produced by the²⁷Al(α, 3p)²⁸Mg reaction at E_α=140 to 30 MeV with thick target yields of 40 μCi/μAh. The carrier-free²⁸Mg is separated from the matrix activities by coprecipitation and anion exchange with chemical yields of 80%.     

Autoassembly of cage structures. 4. Stereochemistry of 2,5-di-tert-butyl-γ-butyrolactone-4-carboxy-s-(α)-phenylethylamide

The diastereoisomeric lactonamides (2a, b), obtained from the dilactone (1) and S-phenylethylamine, have been separated. X-ray crystallography shows that the high-melting isomer (2a) has theR-configuration at the chiral centers C² and C⁴, the enantiomeric conformation of the -lactone ring being of theS-type in thetwist form, intermediate between envelope ² E and semi-chair ₃ ² T. It is shown by molecular mechanics that the minimum steric energy of2a corresponds to a conformation of the heterocycle close to the envelope form₃E. Examination of van der Waals interactions shows that the calculated structure for2a is preferred. The reasons for the nonidentity of the forms of the -lactone ring of2a in the crystal and the free state are discussed. The crystal structure of2a is composed of two geometrically similar independent molecules associated along the axis by weak hydrogen bonds of two types, the energies of which have been estimated from the v_XH values, which are related by the expression v_XH=f(R_X...O), where X=N, O.For previous communication, see [1].N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117977 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 7, pp. 1601–1611, July, 1992.     

Bilayer studies in mixedn-decanol/n-tetradecanol complexes ofn-decylammonium beidellite

Complexes have been prepared by treatment ofn-decylammonium beidellite with mixtures ofn-decanol andn-tetradecanol with different concentrations. Measurements of the basal spacings of the obtained complexes have been performed in a wide range of temperatures. Three different bilayer phases have been established between (20 and 70°C: the _i(C₁₀) phases (=bilayers ofn-decyl chains); the _i(C₁₀/C₁₄) phases (=mixed bilayers ofn-decyl andn-tetradecyl chains in molar ratio approximately 1:1) and the _i(C₁₄) phases (=bilayer ofn-tetradecy 1 chains with then-decylammonium ions included). In all bilayer phases the chains stand perpendicular to the silicate interfaces. In definite concentration ranges two of the phases coexist, i.e., miscibility gaps occur, which disappear at temperatures higher than the temperature of the _i/ transition. The miscibility gaps are reversible with temperature. The composition of the intercalated bilayers has been studied by HPLC of the excess alkanol mixture separated from the beidellite complexes after the equilibrium has been reached. There is preferential adsorption of one of two alkanols from the mixture, which is in agreement with the observed miscibility gaps. The space filling problem as well as the structure of the three bilayer phases observed have been discussed.