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991.
R. K. Mittal J. P. Tandon R. C. Mehrotra 《Fresenius' Journal of Analytical Chemistry》1962,189(4):330-336
Summary In the present investigations, the standardization of vanadium(II) solution against ferric and cupric salts has been described and a few visual indicators have been shown to be applicable in the above titrations. When iron(III) solution is added to vanadium(II) solution neutral red marks the end point for VII to VIII change. This change is also noted when vanadium(II) solution is added to ferric solution in the presence of excess of concentrated hydrochloric acid at an elevated temperature and neutral red and phenosafranine as visual indicators. Under the same conditions, the end point with eupric solution also corresponds to this change.When vanadium(II) solution is added to ferric solution at an elevated temperature in the presence of methylene blue or gallocyanine as visual indicators, the end point marks VII to VIV change. A mixture of iron and copper has also been titrated successfully with the help of visual indicators.
Thanks of the authors are due to the C.S.I.R. authorities for providing a Junior Research Fellowship to one of them (R.K.M.). 相似文献
Zusammenfassung Zur Einstellung von Vanadium(II)-lösungen mit Eisen(III)- oder Kupfer(II)-salzen werden als visuelle Indicatoren Neutralrot, Phenosafranin, Methylenblau oder Gallocyanin benutzt. Bei Zugabe von Eisen(III)-lösung zur Vanadium(II)-lösung zeigt Neutralrot den Übergang VII VIII an. Dieser Übergang wird ebenfalls von Neutralrot und Phenosafranin angezeigt, wenn Vanadium(II)-lösung in Gegenwart von überschüssiger konz. Salzsäure bei erhöhter Temperatur zu Eisen(III)- oder Kupfer(II)-lösung gegeben wird. Der Übergang VII VIV wird von Methylenblau oder Gallocyanin angezeigt, wenn Eisen(III)-lösung bei erhöhter Temperatur mit Vanadium(II)-lösung titriert wird. Die Titration eines Gemisches von Eisen(III) und Kupfer(II) wird ebenfalls ausgeführt.
Thanks of the authors are due to the C.S.I.R. authorities for providing a Junior Research Fellowship to one of them (R.K.M.). 相似文献
992.
Rathore N. S. Pabby Anil Kumar Venugopalan A. K. 《Journal of Radioanalytical and Nuclear Chemistry》2004,262(3):543-549
Hydrated iron oxide or amorphous-Fe2O3·3.5 H2O (HFeO), hydrated titanium oxide (HTiO) and hydrated thorium oxide (HThO) were synthesized and their applicability for the decontamination of intermediate level liquid wastes (ILLW) was tested. The sorption of a few actinides like plutonium and americium on HFeO, 137Cs and 106Ru on HTiO and 90Sr on HThO was investigated as a function of pH, time and loading capacity of the hydrous oxide with metal ions. The influence of the total dissolved salt content was also monitored. Some of these parameters influenced the sorption behavior significantly. The radiation stability of these inorganic sorbents were studied by irradiating them up to 48 Mrad. Adsorbed actinides and fission products were successfully eluted from HFeO and from the mix-bed of HTiO and HThO by 0.5M nitric acid.The authors wish to thank Shri R. D. Changarani, Chief Superintendent NRG Facilities and Shri P. K. Dey, Head FRD for their valuable advice and constant support. 相似文献
993.
Standard papers regulating the quality of waters of different types are considered. Procedures for determining water quality indexes are briefly reviewed.__________Translated from Zhurnal Analiticheskoi Khimii, Vol. 60, No. 8, 2005, pp. 886–893.Original Russian Text Copyright © 2005 by Kutseva, Kartashova, Tchamaev. 相似文献
994.
De Wasch K Le Bizec B De Brabander H André F Impens S 《Rapid communications in mass spectrometry : RCM》2001,15(16):1442-1447
In previous work (Le Bizec et al., Rapid Commun. Mass Spectrom. 2000; 14: 1058), it was demonstrated that a boar meal intake could lead to possible false accusations of abuse of 17beta-nortestosterone in antidoping control. The aim of the present study was to identify and quantify endogenous 19-norsteroids in boar edible tissue at concentrations that can alter the steroid urinary profile in humans, and lead to excretion of 19-norandrosterone (19-NA) and 19-noretiocholanolone (19-NE). The samples were analysed in two laboratories. The methodologies used for extraction and detection (GC/MS(EI) and LC/MS/MS(APCI+)) are compared and discussed. 19-Norandrostenedione (NAED), 17beta- and 17alpha-nortestosterone (bNT, aNT), and 17beta- and 17alpha-testosterone (bT, aT) were quantified. The largest concentrations of NAED and bNT were observed in testicles (83 and 172 microg/kg), liver (17 and 63 microg/kg) and kidney (45 and 38 microg/kg). A correlation between the bNT and NAED content of a typical meal prepared with boar parts and the excreted concentrations of 19-NA and 19-NE in human urine was demonstrated. 相似文献
995.
We present a density functional scheme for calculating the frequency-dependent linear response of superconductors. The central result is a set of integral equations determining the linear response of the normal and anomalous densities to external perturbations. Analytic solutions of these integral equations are obtained for homogeneous systems with separable effective interactions. For inhomogeneous superconductors, the formalism leads to a scheme for calculating the critical temperature without explicitly solving the gap equation. © 1995 John Wiley & Sons, Inc. 相似文献
996.
K. V. Fedotov 《Chemistry of Heterocyclic Compounds》1992,28(8):937-940
Asymmetric carbocyanine dyes, the solutions of which are characterized by the presence of several absorption bands in the visible and near-IR regions, were synthesized from 4,5-dimethyl-1-oxo-2-phenyl-1,5-dihydrothiazolo[3,2-a]quinoxalin-3-ium perchlorate. Their deep color is due both to a more effective length of the condensed heterocyclic system and to the strong interaction of the electronic transitions, localized on the polymethine chain and on the heterocyclic ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1113–1116, August, 1992. 相似文献
997.
Sh. Yu. Islambekov A. K. Karimdzhanov S. M. Mavlyanov A. I. Ismailov 《Chemistry of Natural Compounds》1991,26(3):239-250
Information is given on vegetable tanning substances, their classification, distribution in the plant world, and structure, and the dependence of their tanning properties on their composition, and also on methods of enriching tanning extracts. The review of literature sources includes publications from 1950 to 1989.A. S. Sadykov Institute of Bioorganic Chemistry, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 293–307, May–June, 1990. 相似文献
998.
The structure of the abnormal product 1a formed in the Knoevenagel condensation of 2-carbethoxycyclohexanone and malononitrile has been further confirmed. Oxidation of the tetrahydroisoquinoline 3b using Na2Cr2O-AcOH-H2SO4 gave the keto isoquinoline 3d and the isoquinoline-1-carboxylic acid 5a. The acid chloride of 5a was condensed with diethyl ethoxymagnesiomalonate to afford after decarbethoxylation the methyl ketone 5d which on Baeyer-Villiger oxidation gave a mixture of the acetate 1g and the title compound 1b. The unambiguous synthesis of 1b confirms the structure assigned earlier to the title compound also formed during the partial hydrolysis of the diethoxy compound 1c. Condensation of 2-acetylcyclohexane-1,3-dione with malononitrile gave the quinoline derivative 4c which on ethylation yielded the ketoquinoline 4d. The present studies have confirmed that the quinoline compound 4a is also formed in the condensation of 2-acetylcyclohexanone and cyanoacetamide. 相似文献
999.
The title compounds, which contain six-membered chelate rings locked in the chair conformation, have been prepared by the reaction of (C6H5)3P with the appropriate tetracarbonyl derivative in refluxing mesitylene. 相似文献
1000.
Pharmaceutical counterfeiting 总被引:2,自引:0,他引:2
Deisingh AK 《The Analyst》2005,130(3):271-279
Pharmaceutical counterfeiting is becoming a serious problem both in developed and developing countries. This paper considers the extent of the problem and provides several examples of drugs which have been counterfeited. Additionally, the effects of counterfeit products on consumers, health care providers, drug manufacturers and governments are discussed. Several of the currently used methods of detection are described and these include near-infrared spectroscopy, Raman spectroscopy, isotopic characterization, tensiography, chromatographic and mass spectrometric approaches. Finally, anti-counterfeiting measures such as the use of holograms, tracers and taggants and electronic tracking are summarized. 相似文献