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1.
Thermal lens spectrometry was used to study the dissociation kinetics of diethyldithiocarbamate complexes of copper(II), cobalt(III), and nickel(II) as a function of pH in the presence of chloride and sulfate ions. It is shown that, as distinct from conventional spectrophotometric and potentiometric measurements, the reversible dissociation of the test complexes and the irreversible oxidation of the ligand can be studied separately (at a level of n × 10–8n × 10–6 M) using thermal lens spectrometry. Because of work in more dilute solutions and due account of the kinetic features of the systems in question, thermal lens spectrometry provides a higher accuracy of the determination of stability constants for diethyldithiocarbamate complexes of copper(II), cobalt(III), and nickel(II). The adsorption of the diethyldithiocarbamate complexes in question from water–ethanol solutions (1 : 3) on Silasorb C18 silica is studied, and the adsorption constants are determined. The limits of detection of copper(II), cobalt(III), and nickel(II) diethyldithiocarbamates obtained in extraction–thermal-lens determination are n × 10–8 M.  相似文献   

2.
A spectrophotometric method for the determination of cobalt and nickel using a new reagent sodium ethylthioxanthate has been described. The yellow-colored cobalt complex and red-colored nickel complex have been extracted quantitatively using carbon tetrachloride in the pH ranges 4.0–11 and 4.0–6.7, respectively. The colors of these complexes are stable and absorbances have been measured at 389 nm for cobalt and 495 nm for the nickel complexes. Few ions interfere but the method has been applied successfully for the determination of these metal ions in various complex materials.  相似文献   

3.
    
Ulocladols A and B — new exometabolites having a mixed sesquiterpenoid-polyketide nature that are structurally close to the host-specific toxins ofAlternaria citri — have been isolated from the deuteromyceteUlocladium chartarum. Both substances inhibit the growth of cotton seeds.All-Union Scientific Research Institute of Phytopathology, Moscow Province, Golitsyno. M. V. Lomonosov Moscow State University. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 642–648, September–October, 1991.  相似文献   

4.
The cobalt, nickel and copper complexes of dithio-oxamidc have been characterized in terms of color, effect of pH, structure in solidion, order of addition of reagents, adherence to Beer's law and sensitivity. The reactivity of the reagent to other ions has been reported. A method for the simultaneous spectrophotometric determination of cobalt, nickel and copper has been developed. the results of the application of this procedure to synthetic samples and to several National Bureau of Standards Samples are given.  相似文献   

5.
The cobalt, nickel and copper complexes of N,N'-bis(3-dimethylaminopropyl)dithio-oxamide have been characterized in terms of color, effect of pH, rate of color formation, structure in solution, order of addition of reagents, adherence to Beer's law, and sensitivity. The reactivity of the reagent to other ions has been reported. A method for the simultaneous spectrophotometric determination of cobalt, nickel and copper has been developed. The results of the application of this procedure to synthetic samples and to several National Bureau of Standards samples are given.  相似文献   

6.
Summary Three new substances — tenuferin, tenuferinin, and tenuferidin — have been isolated from the roots ofFerula tenuisecta Eug. Kor. It has been shown that they are esters of an undescribed sesquiterpene alcohol — 8,10-dihydroxy-3,4-epoxyguaiane — and isovanillic, vanillic, and p-hydroxybenzoic acids, respectively.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodynkh Soedinenii, No. 1, pp. 70–75, January–February, 1978.  相似文献   

7.
    
Summary A new polyphenol — listvenol — has been isolated from the bark ofLarix sibirica Ledeb. Structure (I) is proposed for it on the basis of chemical and spectral characteristics.S. M. Kirov Kazakh State University. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 623–629, September–October, 1973.  相似文献   

8.
A simple and sensitive spectrophotometric method for the determination of cobalt, nickel and copper with desferrioxamine-B (desferal) is described. The sensitivity of the colour reactions of cobalt, nickel and copper is increased by introducing desferal. The pH range for the formation of Co II, Ni II or Cu II-desferal. Chelates is 4.5–8.5, 5.5–9, and 6.5–9.5, respectively. The molar absorptivities of the chelates are 1.2·105, 5.6·104 and 4.8·104 at 545 nm, 390 nm and 680 nm, respectively. Beer's law is obeyed up to 10 g/ml of metal ion. The effect of desferal concentration, pH, standing time and interfering ions are discussed. The method was applied to the determination of trace amounts of cobalt, nickel and copper in steel and simulated radioactive wastes.  相似文献   

9.
The class compositions of the lipids of leaf vegetables —Spinacea oleracea (variety Ispolinskii),Latuca sativa (variety Kucheryavets Odesskii), andRumex acetosa (variety Odesskii-17) have been studied. The compositions of their NLs (17 groups of individual compounds were identified), GLs (nine groups of compounds were found), and PhLs (seven groups of compounds have been found) have been determined by physicochemical methods of analysis. The maximum amount of the total lipids and also of the PhLs was possessed by the spinach. Among the FAs of the leaf vegetables, USFAs predominated.M. V. Lomonosov Technological Institute of the Food Industry, Odessa. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 199–205, March–April, 1993.  相似文献   

10.
The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.  相似文献   

11.
ESR and DRES were used to study the state of the cobalt, nickel, and copper ions in catalysts obtained by dissolving cobalt-, nickel-, and/or copper-containing activated aluminum alloys in water with subsequent roasting or impregnation of the support obtained by dissolving activated aluminum in water and solutions of Co, Ni, or Cu nitrates. The formation of highly dispersed M0 aggregates, which are rather readily oxidized, is characteristic before heat treatment for Co-and Ni-containing catalysts obtained from the alloys. In the case of Cu-containing systems, several types of copper ions are observed independently of the method of synthesis even before heat treatment. Heat treatment leads to the aggregation of oxidized Co2+ ions to give highly dispersed oxide phases. The roasted nickel and copper catalysts contain several types of nickel and copper ions, respectively.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 9, pp. 1987–1992, September, 1992.  相似文献   

12.
Binary complexes of α-hydroxy acids (L-Tartaric acid and L-Malic acid) with d-electron metal ions (copper, cobalt, nickel) were investigated. Potentiometric measurements have been performed in aqueous solution with computer analysis of the data for determination of the stability constants of complexes formed in the studied systems. The coordination mode of the complexes was defined using spectroscopic methods: electron paramagnetic resonance (EPR), ultraviolet-visible (UV-Vis), circular dichroism (CD), and infrared (IR). Results of the equilibrium studies have provided evidence for the formation of dimers with copper(II) ions and monomers with cobalt(II) and nickel(II) ions.  相似文献   

13.
A new hydrolyzable tannin substance has been isolated from an anqueous hydrolysate of an aqueous-acetone extract of the fruit ofRosa platyacantha — 1-dehydrotrigalloyl--D-glucose — and it has been named platyacanthin. The substance is a minor component of the tannin complex.S. M. Kirov Kazakh State University, Alma-Ata. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 829–831, November–December, 1985.  相似文献   

14.
The paper gives a review of the alkaloids ofColchium luteum Baker from various growth sites. The structure of luteidine — one of the main alkaloids of the plant — has been established. In addition, two new alkaloids have been isolated from the plant and the structure of one of them has been established as collutine N-oxide.M. I Kalinin Turkmen Agricultural Institute, Ashkhabad, and V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 810–815, November–December, 1985.  相似文献   

15.
A radiochemical displacement method has been developed for the determination of nickel and cobalt based on the release of Zn-65 from labelled Zn(PAN)2 [1-(2-pyridylazo) 2-naphthol] complex in chloroform. The displacement behavior of Zn-65 by nickel and cobalt was studied in the pH range 5–7.5. The effect of various ions on the displacement was also examined. 2–20 g of nickel and cobalt was determined by the aid of calibration plots.  相似文献   

16.
    
A new alkaloid — leuconine — has been isolated from the epigeal parts ofAconitum leucostomum andA. septentrionale, and its structure has been established on the basis of spectral characteristics.Institute of Chemistry of Plant Substances, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 538–540, September–October, 1992.  相似文献   

17.
Summary From the wood of the Siberian firAbies sibirica Ledeb. and the Khingan firA. nephrolepis Maxim., five new compounds have been isolated which are ester derivatives of the lignans lariciresinol, olivil, and hydroxymatairesinol.It has been established that olivil is esterified at the primary alcoholic hydroxyl by hydroxycinnamic acids — p-coumaric or ferulic — and lariciresinol is esterified by vanillic acid. A representative of the guaialignanolides — hydroxymatairesinol — is esterified at the secondary aliphatic hydroxy group with p-hydroxybenzoic or vanillic acid.Institute of Organic Chemistry, Siberian Branch of the Academy of Sciences of the USSR. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 337–341, May–June, 1977.  相似文献   

18.
Summary The application of internal electrolysis with the Pt-Zn electrode assembly has been described for the separation and determination of nickel and, cobalt (in the 1–5 mg range) from each other and from other ions as well as the determinations of bismuth, copper, cadmium, lead, antimony, nickel and cobalt when present in a mixture.
Zusammenfassung Die Anwendung der internen Elektrolyse mit einer Pt-Zn-Elektrodenanordnung für die Trennung und Bestimmung von Nickel und Kobalt (in der Größenordnung 1 bis 5 mg) nebeneinander und in Gegenwart anderer Ionen wird beschrieben. Desgleichen auch die Bestimmung von Bi, Cu, Cd, Pb, Sb, Ni und Co in einer Mischung.
  相似文献   

19.
Known ecdysteroids — ecdysterone, ecdysterone 22-acetate, polypodin B, integristerone A, and sileneosides A and D — and a new phytoecdysteroid — polypodin B 22-acetate — have been found in the epigeal parts of the plantMelandrium turkestanicum (Rg1.) Vved. (family Caryophyllaceae).Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 480–483, July–August, 1990.  相似文献   

20.
Two new guaiane esters — karaferin and karaferinin — have been isolated fromFerula karakalensis, and their structures and stereochemistry have been established. It has been shown that theFerula sesquiterpene alcohols angrendiol, ugamdiol, and karaferol are biogenetically interconnected and are products of a single chain of the biogenesis of terpenoids in plants.Institute of Chemistry of Plant Substances, Uzbekistan Republic Academy of Sciences, Tashkent; Botanical Garden of Moscow State University. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 227–231, March–April, 1993.  相似文献   

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