An electrolytic device for preparation of hydrogen and oxygen from water for isotopic analysis

An electrolytic device for decomposition of water has been developed which readily gives hydrogen and oxygen for isotopic measurement with a mass spectrometer. A 20-mul sample can be decomposed quantitatively in 10 min with good reproducibility. The results produced are comparable with those obtained by reduction with uranium.     

Soft-laser scanning densitometry performed on a 35-mm slide illustrating SDS-PAGE separation of adenovirion polypeptides

Virion polypeptides (35 S), methionine-labeled and purified by CsCl gradient centrifugation, were separated by SDS-gel electrophoresis. Analysis of their band pattern was performed by scanning the images of the SDS-gels shown on a 35-mm slide. The densitometric tracings revealed the presence of 17 protein bands, although only 15 of them were visible to the naked eye. The high sensitivity and resolving capacities of the soft-laser scanning densitometer enabled us to detect trace amounts of protein bands separated in SDS-gels and to obtain a resolution compatible to that of electrophoresis. Fourfold electronic amplification of the densitometric tracings, produced by a computer, generated new information regarding the pattern of the electrophoregram. The facility to amplify peaks of importance is particularly advantageous when faint or overlapping protein bands revealed on a gel are assessed.     

Natural and fallout radionuclide concentrations in the environment of Islamabad

A study on the concentration of natural and fallout radionuclides in environmental samples collected from different localities of Islamabad was performed. For the determination of gamma-emitters such as ²³⁸U, ²³²Th, ⁴⁰K and ¹³⁷Cs high purity germanium (HPGe) detector was used while for the analysis of ⁹⁰Sr, a beta-emitter, liquid scintillation counting system was used. The indoor absorbed dose rate was measured by a CaF₂ : Dy thermoluminescence detector. Other radiation parameters were also determined to evaluate the radiation hazard. All the results were well within the permissible limits showing that there is no radiation hazard in the environment of Islamabad.     

Structure determination of bioactive galloyl derivatives by NMR spectroscopy

The investigation of the chemical constituents of Symplocos racemosa Roxb led to the isolation of two new glycosides, symcomoside A (1) and symcomoside B (2), together with one known glycoside, tortoside C (3), which is reported for the first time from this plant. The structures of the new compounds were determined by 1D and 2D homonuclear and heteronuclear NMR spectroscopy, from chemical evidence and by comparison with published data for closely related compounds. Symcomoside B (2) showed potent inhibitory activity against alpha-glucosidase in a concentration-dependent fashion with an IC50 value of 0.733 +/- 0.033 mM whereas symcomoside A (1) showed very weak inhibitory activity against alpha-glucosidase (9.90% in 0.70 mM).     

Synthesis of fused ring heterocycles from aromatic amines with hydroximoyl chlorides

Substituted 2-arylbenzimidazoles, 2-arylbenzoxazoles and 2-arylbenzothiazoles were obtained in good yield by the reaction of hydroximoyl chlorides with ortho-substituted aromatic amines. The benzo moiety of the benzimidazoles was shown by nmr to be symmetrical, indicating that the N-H group proton of the imidazole ring is exchanging with the water protons in the DMSO-d₆ solvent.     

Ground state correlation energy of the Be-sequence forZ=4–20 in MCDF approximation

The ground state (J=0) electronic correlation energy of the 4-electron Be-sequence is calculated in the Multi-Configuration Dirac-Fock approximation forZ=4–20. The 4 electrons were distributed over the configurations arising from the 1s, 2s, 2p, 3s, 3p and 3d orbitals. Theoretical values obtained here are in good agreement with experimental correlation energies.     

Detection and assessment of citrus tristeza virus antigens by computer-aided scanning densitometry

Citrus tristeza virus (CTV) extracted from Etrog citron (C.medica L.) was immunoprecipitated. The immunoprecipitate was fractionated by SDS-PAGE and western blotted onto nitrocellulose. The CTV antigens were determined by immunoblot analysis using rabbit anti-CTV IgG, and the protein-band pattern exhibited on the nitrocellulose was assessed by soft-laser scanning densitometry. The densitometric tracing revealed the presence of bands that were not visible to the naked eye. Using the superimposition mode of the instrument, it was also revealed that the protein-band patterns of different CTV samples were not identical. Computer-aided soft-laser scanning densitometry proved to be a powerful approach in the detection and assessment of protein bands revealed on nitrocellulose immunoblots, which we were previously unable to do employing conventional methods.     

Spectrophotometric determination ofo- andp-phenylenediamines

Summary Cupric chloride-triphenylphosphine complex gives red color witho-phenylenediamine having maximum absorption at 505–520 nm and 0.5g/ml as visual limit of identification. The reaction is specific foro-phenylenediamine and obeys Beer's law (1 to 10g/ml). This reaction provides the basis of a new method for the Spectrophotometric determination ofo-phenylenediamine ing quantities.Ruthenium trichloride-triphenylphosphine complex gives blue color withp-phenylenediamine having maximum absorption at 580 nm and 2g/ml as visual limit of identification. On the basis of this color reaction a Spectrophotometric method for the determination ofp-phenylenediamine in hair dyes is described. The recovery of the dye from commercial preparations is better than 97%. Other organic compounds do not interfere.

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Zusammenfassung Kupfer(II)chlorid-triphenylphosphin reagiert mito-Phenylendiamin unter Rotfärbung mit maximaler Absorption bei 505 bis 520 nm und 0,5g/ml als Erfassungsgrenze. Die Reaktion ist für o-Phenylendiamin spezifisch und folgt dem Beerschen Gesetz zwischen 1 und 10g/ml. Sie dient als Grundlage für eine neue Methode der spektrophotometrischen Bestimmung von Mikrogrammengen o-Phenylendiamin.Rutheniumtrichlorid-triphenylphosphin reagiert mit p-Phenylendiamin unter Blaufärbung mit maximaler Absorption bei 580 nm und 2g/ml als Erfassungsgrenze. Auf dieser Grundlage läßt sich p-Phenylendiamin in Haarfärbemitteln bestimmen. In handelsüblichen Präparaten werden mehr als 97% des enthaltenen Farbstoffes gefunden. Andere Verbindungen stören nicht.

     

4,4-Acetalidine-bis-(3-methyl isoxazolone-5) as a new colorimetric reagent for the determination of palladium and uranium

Summary Palladium and uranium react with 4,4-acetalidine-bis-(3-methyl isoxazolone-5) in acid medium to give yellow color having a visual limit of identification at 2 and 15g per ml. This color reaction provides the basis of a new method for colorimetric determination of palladium and uranium. Copper also gives yellow color but it cannot be determined with this color reaction because the color intensity is not stable. The maximum tolerable limit of various ions is reported.

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Zusammenfassung Pd und U reagieren in saurem Milieu mit 4,4-Acetalidin-bis-(3-methyl-isoxazolon-5) unter Gelbfärbung mit einer Erfassungsgrenze von 2 bzw. 15g/ml. Diese Farbreaktion dient als Grundlage für eine neue kolorimetrische Methode für Pd und U. Cu gibt zwar auch eine Gelbfärbung, kann aber damit nicht bestimmt werden, da die Farbintensität nicht beständig ist. Die maximal tolerierbare Menge der Fremdionen wird angegeben.