A new photoionization detector for gas chromatography

Summary A new photoionization detector for gas chromatography is discribed. The source of vacuum ultra-violet (VUV) radiation is separated from the ionization chamber by a window and thus the ionization chamber may be run at atmospheric pressure using an intense source of ionizing radiation. The operation consequently is improved and considerably simplified. Except for a ten times reduction in linearity, the performance characteristics of the detector are comparable to those of the flame ionization detector. Filtration of the VUV radiation allows the selectivity to be varied without affecting the dynamic properties of the detector.Z. ternberg, N. Ostoji, Yug. Pat. Appl.     

Co-deposition of Copper and Tin from Acidic Sulfate Solutions Containing Polyether Laprol 2402C: The Effect of Halides

Voltammetry and x-ray photoelectron spectroscopy data show micromolar amounts of halides to noticeably affect co-deposition of copper and tin from acidic sulfate solutions containing polyether Laprol 2402C as the surface-active substance. The reduction of Cu(II) slows down and that of Sn(II) accelerates in the series Cl^– < Br^– < I^–. Compounds on the surface of bronze coatings are oxides of Cu(I) and Sn(II) and halides of Cu(I).     

Synthesis of macrocyclic aliphatic disulfide oligomers from dithiols by oxidative coupling with oxygen using a copper‐amine catalyst

A new effective method is provided for the synthesis of macrocyclic aliphatic disulfide oligomers by catalytic oxidation of aliphatic dithiols with oxygen in the presence of a copper‐amine catalyst. Copyright © 2004 John Wiley & Sons, Ltd.     

Toward artificial developmental regulators

A polyamide-peptide conjugate is designed which recruits sequence specifically the developmental regulator Exd to a cognate DNA site. In particular, an eight-ring hairpin polyamide (Im-Im-Py(C3H6NHR)-Py-gamma-Im-Py-Py-Py-beta-Dp) with a heptapeptide (R = Ac-Phe-Tyr-Pro-Trp-Met-Lys-Gly-) attached on a central ring was shown to induce cooperative binding of the Drosophila Hox protein cofactor Exd with a Kd of 4.4 nM in vitro, an order of magnitude more efficient than the natural Hox protein partner Ubx. The conjugate joins two sequence specific domains, one for DNA and one for the protein. This small molecule thus serves as a cooperative protein-DNA dimerizer, which mimics the natural Hox family of developmental regulators.     

1-Aroylmethylisoquinolines

The reaction of 1-aroylmethyl-2-benzoyl-1,2-dihydroisoquinolines with the hydrideion acceptor 2,2,6,6-tetramethyl-1-oxidopiperidinium perchlorate gives stable N-acyl salts, which are converted to either 1-aroylmethylisoquinolines or anhydro bases when they are treated with some bases.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1662–1664, December, 1979.Original article submitted January 31, 1979.     

Identification and determination of aesculin and aesculetin in ash barks by capillary zone electrophoresis

Summary A capillary zone electrophoresis method for identification and determination of aesculin and aesculetin has been established using borate-phosphate buffer containing 30% ethanol with on-column UV detection. A detailed investigation of the influence of changes in borate concentration, pH, applied voltage, temperature and organic modifier was then carried out. For both aesculin and aesculetin, a linear plot of migration time (MT) against borate concentration was obtained, and ln[measured peak area (MA)] and lnMT both gave linear plots against ln(applied voltage) with correlation coefficient r>0.999, which also resulted in a linear correlation between MA and MT (r≥0.9998) under varied voltage. Ethanol as organic modifier to the background electrolytes helped in separating aesculin and aesculetin from other components in ash barks. The reproducibility with relative standard deviation in MT and in normalized peak area(NA) and linearity based on NA against concentration were evaluated. Finally, the method was successfully applied to monitor the quality of different ash barks and to compare the effect of sample preparation on content of bioactive components in ash bark. Results indicate that CZE promises to be applicable to quality control of traditional Chinese medicines containing aesculin and aesculetin.     

Sulphate analysis in uranium leach iron(III) chloride solutions by inductively coupled Argon Plasma Spectrometry

Inductively coupled Argon Plasma Spectrometry is used for the indirect determination of sulphate in iron(III) chloride leach solution of Elliot Lake uranium ores via addition of a known amount of barium ions and analyzing for excess of barium. The ore contains approximately 7 wt% pyrite, FeS(2) as the major mineral which oxidizes to generate sulphate during leaching with fe(III). The effects of pH, the concentrations of Fe(III) and chloride ions and for presence of ethanol in the test samples on the accuracy of analysis are studied. It is found that unlike the Rhodizonate method, removal of iron(III) from or addition of ethanol to the test sample prior to analysis are not required. Linear calibration curves are obtained.     

Cyclohexane conversion on nickel mordenite

Two series of nickel mordenite catalysts have been prepared on the basis of Na-mordenite and H-mordenite. Their catalytic activity in cyclohexane conversion has been studied. It has been found that the properties of the catalysts are strongly dependent on the acidity of mordenite.

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NaM HM. .

     

Theoretical study of the CCl3 radical

Employing the STO-3G and 4–31 G basis sets within the unrestricted Hartree-Fock method the equilibrium structure of the CCl₃ radical was calculated. The calculations predict the radical to be non-planar with both basis sets used. Using the UHF optimized geometries the SWX_α calculations have been performed to calculate energy levels, ionization potentials and electron affinities of CCl₃.     

Preparation of N-(β-acetoxyethyl) anabasine,-brucine, -strychnine,and -cocaine iodides and a study of some of their biological properties

A. S. Sadykov Institute of Bioorganic Chemistry, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 413–415, May–June, 1990.