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Table of Content

    24 January 1981, Volume 2 Issue 1
    Articles
    THEORETICAL STUDY OF HIGH PRESSURE ION EXCHANGE CHELATE DISPLACEMENT CHROMATOGRAPHY USED FOR SEPARATING RARE EARTHS-BOUNDARY BETWEEN STEADY ZONES
    Ling Daren, Zhao Aimin, Xin Wenda, Chen Liquan, Fu Lian, Qiu Ling
    1981, 2(1):  1-11. 
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    Expounding the equality between the equation based on the rate theory and that on the theory of equilibrium and its condition, using the micro-resins with the diameters of 30-40μ and 40-60μ respectively and using DTPAas displacer to separate rare earths by high pressure ion exchange chelate displacement chromatography at 75±3℃, the report has experimentally shown that the film diffusion of ions is the control step and decides HETP, which provides the theoretical base of employing Displacer I (a displacer with certain chelate agent concentration, pHand various concentrations of neutral salt) into high pressure ion exchange ehelate displacement chromatography.By examing and discussing the dependence of HETPupon the experiment conditions we have proved Snyder's formula is suitable for high pressure ion exchange chromatographic process.
    THE STUDY OF MECHANISM OF CHELATE AND SYNERGISTIC EXTRACTIONS BY THE METHOD OF TWO-PHASE TITRATIONS
    Li Lemin(Li Lo-min), Xu Guangxian(Hsu Kwang-hsien)
    1981, 2(1):  12-24. 
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    The method of two-phase titrations was first suggested by D.Dyrssen (1952) and B.S.Jensen (1959).In the present investigation we have extended the method to the study of mechanism of chelate and synergistic extraction and for the determination of stability constants of mixed ligand complexes of the following type:Mn++nA- +j(HA)(a) +kB(o) = MAn(HA)j(B)k(o) βnjk = (MAn(HA)j(B)k)o/(Mn+)(A-)n(HA)of(B)ok and we have offered a new and rigorous derivation of the theoretical formulas necessary for the evaluation of βnjk, The method was applied to the study of the mechaniam of chelate and synergistic extraction of zinc ion with l-pheny-3-methyl-4-benzoyl-pyrazolone(HPZL) and TBPin benzene.The results and the scope of applicability of the two-phase titration method were discussed.
    ELECTROCHEMICAL STUDIES OF RARE EARTH ELEMENTS-I——POLAROGRAPHIC STUDY OF EUROPIUM
    Li Ruiliang, Gao Xiaoxia(Kao Sheau-shya)
    1981, 2(1):  25-36. 
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    The ac polarographic behavior of Eu+3 ions in three base solutions (NH4SCN, EDTA-NaCl,DTPA-NaCl) has been compared.In DTPA-NaCl solution the polarographic reversibility of Eu(Ⅲ)is the best among them.The optimun conditions for the polarographic determination of Eu(Ⅲ)are: pH≥6.5, NaCl concentration≥0.3M, the concentration of DTPAshould be slightly higher than the total concentration of all the metal ions which can form complexes with DTPA.Under these conditions, the lower limit of detection of Eu(Ⅲ).is 2×10-6Mby ac polarography or single sweep oscil-lographic polarography, or 2×10-7Mby differential pulse polarography.Other rare earth ions do not interfere.Small amounts of Eu in samples of mixed rare earth oxides were determined by this method with satisfactory results.
    INVESTIGATIONS ON OSCILLOPOLAROGRAPHIC TITRATION——IV TITRATION OF Ca IN PRESENCE OF Mg
    Kao Hung Weng Yunrong, Yin Changqing
    1981, 2(1):  37-42. 
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    Application of oscillopolarographic titration to EGTAtitration of Ca in presence of Mg gives satisfactory results, with Ca:Mg = 1:40.Small amounts of Fe、Al、Ti、 Mn and Pb, which are precipitated in the titration cell without filtration give no interference.The end point is sharp.Being rapid and accurate, the method can be used in limestone analysis.
    METHYL THYMOL BLUE TERNARY COMPLEX SPECTROPHOTOMETRIC DETERMINATION OF MICROAMOUNT CADMIUM IN AIR
    Wang Huaigong
    1981, 2(1):  43-49. 
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    In this paper the condition and composition of the ternary complex for determination of cadmium with Cd-methyl thymol blue-cetyl trimethyl ammonium bromide have been put forward.This method is characterized by high sensibility and good sebectivity, and especially by stable colour with rapid reaction.We have, moreover, proposed a new method tb determine cadmium in air, without separating Cd from its accompanying elements, with ammonium fluoride and phenanthroline as masking reagents of Ni, Co, Mg cations.
    A STUDY OF 1-ISONICOTINOYL-4-AROYLTHIOSEMICARBAZIDES COMPOUNDS
    Zhang Ziyi, Chen Limin
    1981, 2(1):  50-54. 
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    For the purpose of studying the relation between molecular structure and tuberculostatic activity in acylthiosemicarbazide group, some new derivatives of thiosemicarbazide such as 1-isonicotinoyl-4-halogen-aroyl-thiosemicarbazides have been synthesized.These new compounds ware prepared by developing the reaction of the halogen aroylisothiocyanate with isonicotinoyl hydrazide In acetone, acetonitrile or djoxane in yield of 50-80%.
    RESEARCHES ON CERTAIN THIOPHOSPHATIC INSECTICIDES CONTAINING NAPHTHALENE RING
    Yang Shixian(Yang Shih-hsien), Chen Tianchi(Chen Tien-chih), Chen Qinghua(Chen Chin-hua)
    1981, 2(1):  55-62. 
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    Forty thiophosphates containing naphthalene ring have been synthesized and tested as insecticides.The results indicated that most of these compounds were lowly toxic and some of them have high biologic activities to insects.
    STUDY OF GEOMETRIC ISOMERS OF SOME VINYLPHOSPHATE INSECTICIDES-I——THE INFLUENCE OF VARIOUS REACTION CONDITIONS ON THE Z/E RATIO IN THE SYNTHESIS OF DIMETHYL 1-ETHOXYCA- RBONYL 1-PROPEN-2-YL PHOSPHATE(MIE -YA-JING)
    Shao Ruilian, Dong Xiyang, Zhang Chunzao
    1981, 2(1):  63-69. 
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    The insecticide (Mie-ya-jing) dimethyl 1-ethoxy 1-propen-2-yl phosphate has been prepared under different reaction conditions.Synthetic methods, catalysts and solvent exhibit significant influence on the E/Zratio of the products.
    STUDIES ON CHIRAL THIOPHOSPHORIC ACIDS AND THEIR DERIVATIVES-I——THE RESOLUTION OF O-ETHYL-O-PHENYL PHOSPHOROTHIOIC ACID AND THE SYNTHESIS OF ITS CHIRAL THIOL-ESTERS
    Tang Chuchi, Wu Guiping, Chai Youxin
    1981, 2(1):  70-76. 
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    Through quinine salt O-ethyl-O-phenyl phosphorothioic acid(I) has been successfully resolved in methanol solution.
    SELECTIVITY OF INTERMOLECULAR FORCE
    Jin Songshou, Tang Xinshuo
    1981, 2(1):  77-88. 
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    Up to date, the orders of many physical properties, such as reduced retention time on gas chromatography, solubilities, solvation, boiling points, etc.cannot be explained satisfactorily with the dipole moment, polarizibility and molecular weight of the molecule as well as the consideration of the formation of hydrogen bond and electron-transfer complex.It is caused by the selectivity of intermolecular force, in other words, by the presence of some unknown specific interaction between the molecules, described by many authors.The authors have investigated the intermolecular forces among various compounds, by applying the combined method of gas chromatography and molecular models.The observed results show that the presence of the strengthening interaction between the adaptable groups existing on the different compounds respectively.
    PROTON MOBILITY IN NH4Y ZEOLITE-I——THE HEAT OF ADSORPTION OF NH3 ON HY ZEOLITE AND PROTON MOBILITY IN NH4Y OBTAINED BY THE CNDO/2 METHOD
    Yan Deguan, Xue Zhiyuan
    1981, 2(1):  89-96. 
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    The heat of adsorption of NH3 on HYzeolite has been obtained by CNDO/2 method using (AO)3 AlOHSi(AO)3 clusters.The result is closed to the experimental data.It is demonstrated that the proton moving from oxygen on surface of HYzeolite to nitrogen of adsorbate would prefer some site for energetic reason.Appering in the curve of potential energy were two minima.One of minima with distance-1.138Å is near oxygen and the other one-1.720Å is far away from oxygen but near nitrogen.From one minimum to the other the barriar must be climbed over.The value of potential barriar is 9.4kcal/mol from the side of oxygen and 11.9 kcal/mol from the side of nitrogen.Energy difference between the two minima is 2.5 kcal/mol.When NH3 is adsorbed on cation site, the proton moves a distanc from 1.085Å (between the oxygen and proton) to 1.138Å; The system was evolved energy 21.9kcal/mol.and then the proton climbed over the barriar to arrive at a lower minimum, evolved energy 2.5kcal/mol again, hence the total heat of the adsorption was 24.4 kcal/mol (experiment: 25.7kcal/mol).The turnover number for the proton from the side of nitrogen to the side of the oxygen of the framework in the supercage is 1.92×109 sec-1 at 400℃.
    RAMAN AND INFRARED SPECTRA OF RARE EARTH ACETYLACETONATE COMPLEXES——I
    Liang Yingqiu, Liu Juzheng, Liu Guofa, Zhao Yongnian, Wang Yutian
    1981, 2(1):  97-104. 
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    In this work, the Laser Raman and infrared spectra of 15 rare earth acetylacetonate complexes in the region 300-3300cm-1 are studied.The bands near 401 and 415 cm-1 are sensitive to a change in rare earth ion.The frequencies of these two bands change periodically with atomic number, showing the "tetrad effect" and ihe "inclined Weffect" characteristic of lanthanides, and the former was first observed in spectra of rare earth complexes.These effects provide strong evidence for assigning the band near 401cm-1 to the MO2 symmetric stretch and that near 415cm-1 to the MO2 antisymmetric stretch.Adiatomic molecule approximation may be used to estimate the M-Ostretching force constants from the M-Ovibrational frequencies.If the force constant is plotted against the atomic number, the curve shows also the "tetrad effect" .If the force constant is plotted against the logarithm of the stability constants of these complexes, two straight lines having different slope were obtained for light and heavy rare earth ions which cross at Eu.Since the force constants vary appreciably compared to the variation in stability constants for heavy rare earth acetylacetonate complexes, the force constant is a more precise structure parameter for describing these complexes.The C-Ostretching frequency in the infrared spectrum of acetylacetone decreases upon coordination with rare earth metal ions, which indicates that the charge transfer occurs.The negative charge in the acetylacetonate ring tends to be delocalized.Rare earth acetylacetonate complexes are usually considered to be ionic, but the present result indicates that a certain amount of covalency is present.
    INFRARED STUDY OF ETHYLENE CHEMISORBED ON SILICASUPPORTED PALLADIUM
    Wu Tonghao, Yang Hongmao, Zhao Fangqing
    1981, 2(1):  105-111. 
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    Infrared spectra of ethylene chemisorbed on silicasupported palladium at 15℃ have been obtained.On hydrogenation of the chemisorbed surface species at 15℃, ethane and a smaller amount of n-butane were formed.The experiment indicated that ethylene chemisorbed on silicasupported palladium formed three surface species: the σ-bond type surface species PdCH2CH2Pd; the n-butyl type surface species CH3 CH2 CH2 CH2 Pd, probably via a self-hydrogenation and surface dimerization; and the surface carbide probably via the dissociative chemisorption of ethylene.
    DETERMINATION OF SEVERAL MINOR NUTRIENT ELEMENTS IN TEA BY ATOMIC ABSORPTION SPECTROMETRY
    Wang kaixiong, Xie xuyi, Zhou zhirui
    1981, 2(1):  112-116. 
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    A convenient and accurate method for the determination of copper, manganese, iron and zinc in tea by aspirating directly the sample solution into a flame atomic absorption spectrometer is described.The conditions of dry ashing of the tea leaves and preparation of the sample solution have been studied.The interference of other ions contained in the sample solution has been examined and found to be negligble.Astandard addition method has been made and the results obtained are in agreement with that of the standard curve method.The recovery and the precision of this method are quite satisfactory.Finally, twenty-live different samples of famous china tea have been analysed by this method, and the content ranges of copper, manganese, iron and zinc in these samples are Cu 9 -65, Mn 185-1600, Fe 105-320, and Zn 35-93 ppm.
    INVESTIGATIONS ON OSCILLOPOLAROG RAPHIC TITRATION——V——TITRATION OF Ni BY DIMETHYLGLYOXIME
    Weng Yunrong, Chern Tzunrong, Kao Hung
    1981, 2(1):  117-121. 
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    In NH4OH-NH4Cl buffer solution, Ni can be directly titrated by standard alcoholic solution of dimethylglyoxime, using the appearanceof the incision on (dE)/(dt) - Ecurve of dimethylglyoxime to indicate the endpoint of titration.Fe(III), Al(III), Mn(IV), Ti(IV) and Pb(II) which form precipitates in the medium do not interfere.This is an example to show that tedious gravimetric technique can be advantageously replaced by a simpler volumetric technique of oscillopolarographic titration.
    THE STUDY OF THE ACTIVITY OF AROMATIC AND HETEROAROMATIC COMPOUNDS TOWARDS ELECTROPHILIC SUBSTITUTION REACTIONS
    Zhang Jiancheng, Liu Xinhou, Wu Wei, Liu Rouzhuang
    1981, 2(1):  122-126. 
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    The order of the activity of 5 aromatic and heteroaromatic compounds towars electrophilic substitution reaction was determined,namely,anthrac-ene-thiophene>naphthalene>benzene>pyridine.CNDO/2 calculations show that the activity order and the orientation of aromatic and heteroaromatic compounds towards the electrophilic substitution reactions were not determined by the charge distribution,but by the π-electron polarizability (superdelocalizability) of the reaction sites.
    HERBICIDAL DIALLATE-TRIALLATE MIXTURES——Ⅱ——A NEW SYHTHESIS OF 1,2,3-TRICHLORPROPENE AND 1,1,2,3-TETRACHLOROPROPENE
    Wang Jinxian
    1981, 2(1):  127-130. 
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    1,2,3-Trichloropropene and 1,1,2,3-tetrachloropropene have been pre-parad in 86% yield by the following procedure:1.Dehydrochlorination of 1,2,3-Trichloropropane with 30% Sodium hydroxide and a surfactant gives 90-92% yields of 2,3-dichloropropen(I).2.Catalytic chlorination of 2,3-dichloropropene (I) with AlCl3 at 85℃ gives a mixture of 37% 1,2,2,3-tetrechloropropane (Ⅱ) and 53% 1,1,2,2,3-pentachloropropane (Ⅲ).3.Dehydrochlorination of (Ⅱ) and (Ⅲ) with 30% Sodium hydroxide and a surfactant to give a mixture of 39% 1,2,3-Trichloropropene (Ⅳ) and 43% 1,1,2,3-Tetrachloropropene (V).The total yield is 86%.Reaction mixture of (Ⅳ) and (V) with diisopropylamine and carbon-oxysulfide gives a herbicidal mixture of 33-39% S-(2,3-dichloroallyl) diisopropylthiolcarbamate (Diallate) (Ⅵ) and 47-53% S-(2,3,3-Trichloroallyl) diisopropylthiolcarbamate (Triallate) (Ⅶ), The total yield is above 80%.