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    24 August 1983, Volume 4 Issue 4
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    Articles
    MEASUREMENT OF THE PHASE DIAGRAM OF MOLTEN SALT SYSTEM NaCl-CaCl2-SrCl2
    Mo Wenjing, Wu Shimin, Qiao Zhiyu, Zhu Yuankai
    1983, 4(4):  395-400. 
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    In this paper, the phase diagram of molten salt system NaCl-CaCl2-SrCl2 has been determined by MDTA with high sensitivity, using the calculated phase diagram as a prior one. Especially, it is considered that supercooling of salts affects the accuracy of measurement.This ternary system contains an eutectic point at 41.9 mol% NaCl,40.0 mol%CaCl2, 18.1 mol%SrCl2, 744K. In the liquidus surface for saturation with the CaCl2-SrCl2 solid solution unvariant line starts at 823K, and the liquid composition is 24.8 mol%NaCl, 50.1 mol%CaCl2,25.1 mol%SrCl2.This phase diagram is important for the practice of sodium electrolysis. It may furnish an example in judging the reliability of a thermody-namic model that has been applied for calculation of the phase diagrams of charge-asymmetric ternary molten salt systems.
    OF THE PREPARATION AND CHARACTER OF Fe(Ⅲ)-HEDP COMPLEXES
    Zhuang Ruifang, Xu Wen wen, Dai Anbang, Zhang Jian
    1983, 4(4):  401-406. 
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    K3[Fe(C2H5P2O7)2]·4,5H2O, and K3[Fe(C2H6P2O7)2(OH)2]·3H2O have, been prepared in. solid state and characterized by chemical analysis, Mossbauer spectra, infrared spectra, gravimetric: and differential thermal analysis and conductivity measurement.The two compounds are both high spin complexes. From quadru-pole splitting, the symmetry around Fe atom has been shown by Mossbauer parameters of these complexes as . compared with the values of Fe(Ⅲ)-complexes, The, changes of isomer shifts are dependent on the strength of covalent bond between Fe (Ⅲ) and the ligands.The results of IR spectra and other measurements have also been discussed briefly. A probable stfuctural formula is given for each complex.
    STUDIES ON THE HYDROLYTIC POLYMERIZATION OF CHROMIUM (Ⅲ) ION (Ⅲ)——HYDROLYTIC POLYMERIZATION OF Cr~(3+) AT COMPARATIVELY HIGH CONGEHTRATIONS
    Luo Qinghue, Ren Jianguo, Shen Mengchang, Dai Anbang(Tai An-pang)
    1983, 4(4):  407-413. 
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    The hydrolytic polymerization of Cr3+ at rather high concentrations was studied pH-metrically. Four series of chromic nitrate solutions have been prepared of 0.160M, 0.200M,0.250M and 0.320M concentration, each with various pH and all with 0.5M sodium nitrate. The solutions were hold in polyethylene bottles and kept at 40±1℃. From time to time, a small portion of each solution was taken and its pH was measured at 30±0.1℃. When difference between the pH values measured over an interval of four days was less than 0.005 pH, equilibrium was considered to be established, which usually took about one month.The values of Z, the average number of OH- bound per Cr3+ ,were calculated at different pH. The highest value of Z was about 0.5 for solutions of concentration higher than 0.160M which had Z of about 1.0. Then the Z vs. pH curve was plotted for each concentration, B, The fact that the curves of different concentrations did not coincide but separated from each other indicated that polynuclear coordination compounds had been formed. When B and pH of the same Z from dif-. ferent curves of (Z vs. pH)B were plotted, a linear relationship between -IgB and pH was found. Hence the hydrolytic polymerization reaction took place according to the "core + links" scheme and the product could be represented as Cr[Cr(OH)t]n(3+n(3-t))+, t being the slopes of the straight lines, (-∂lgB/∂pH)B, which is about 1.0 in the region of Z studied. This was the type of"core+links"compound when Cr3+ concentrations was 0.160-0.320M. At lower concentration, t = 2 as reported in part (Ⅰ) of this series of studies.Under the present experimental conditions, n, the number of links in Cr[Cr(OH)]n(3+2n)+ was determined to be 1 and 2 , and the hydrolysis constants obtained are as follows; lgβ1,2 = -2.68, lgβ2,3 =-3.84.
    PURIFICATION OF ALKALI EARTH METAL COMPOUNDS BY THE CHROMATOGRAPHIC ADSORP- TION ACCOMPANIED WITH COMPLEX-FORMATION
    Huang Zhupo, Guo Fengyu, Chen Chaozong, Hou Pincheng
    1983, 4(4):  414-418. 
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    A method of chromatographic adsorption accompanied with complex compound formation was used for purifying alkali earth metal compounds from heavy metal impurities. This method provides a means to remove the following impurities to an extent of ppm level, such as Fe<0.4, Co<0.1, Cu<0.5, Ni<0.7, Pb<0.2, Zn<～0.4 ppm. This method enables purification to be accomplished with a higher efficiency and in a larger capacity than that of other methods.The efficiency of several complexing agents and the optimum processing conditions have been studied.
    A STUDY ON THE TERNARY SYSTEM LaCl3·CH3CONH2·H2O AT 0℃ AND 30℃
    Tang Zongxun, Guo Zhizhen, Chen Peihang, Ma Jinhua, Chen Yunsheng
    1983, 4(4):  419-425. 
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    The solubilities and the refraction indices of the saturated solutions in the titled ternary system have been investigated isothermally at 0℃ and 30℃.At 0℃, both the isotherms of solubilities and refraction indices of the system consist of,three branches corresponding to the solid phases, CH3CONH2, LaCl3·4CH3 CONH2·5H2O and LaCl3·7H2O, respectively. The compositions of the two eutonic points are 52.47% (by wt.) CH3CONH2, 21.77,% LaCl3 and 9.46% CH3CONH2,45.59% LaCl3.There is a short metastable segment of solubility curve of LaCl3·7H2O (dotted line) in the diagram, which may. be considered as an extrapolated part of the stable curve of this compound.At 30rC, two phase diagrams were obtained. One was obtained just by stirring the original complexes at 30℃ and the other by preheating the original complexes up to the temperature above the m. p. of CH3CONH2 (81℃) and then stirring at 30℃. The former is a stable system. There are four solid phases,LaCl3·7H2O, LaCl3·4CH3CQNH2·5H2O, LaCl3 and CH3CONH2. The eutonic solution of the first two solids contains 47.19% LaCl3 and 14.48% CH3CONH2.The solubility curve of anhydrous LaCl3 is very short and the other two eutonics can only be estimated as 33%, 59% and 31%, 66%, respectively. The second diagram (shown in dotted line) is a metastable system. Instead of the ternary compound, there is LaCl3·3H2O as one of the solid phases. The first two eutonic solutions now contain 47%, 29% and 43%, 46% of LaCl3 and CH3CONH3, by the estimation, respectively.The density of the ternary compound determined by pycnometricalmethod, using the related mother liquor or benzene as measureing media,is about 1.70 ( 12 ± 1℃) . The photomicrograph and the X-ray diffraction patterns as well as the d/n values of the ternary compound are also given.The solid phase LaCl3·6H2O reported by Z. M. Zholalieva et al. in 1976 was not found both at 0℃ and at 30℃.
    A STUDY ON BINARY SYSTEM LaCl3·4CH3CONH2·5H2O-HO
    Tang Zongxun, Wen Yuxiu, Li Tongsheng, Chen Yunsheng
    1983, 4(4):  426-427,425. 
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    The titled ternary compound has been prepared by mixing LaCI3·7H2O and CH3CONH2 in water with l：4 of the mole ratio of LaC13 to CH3CONH2。The solublities in the titled system at various temperatures as wellas the melting point of the ternary comPound were determined． Accor－ding to thesedata adlagram ofsolublllty ofblnary system LaCI3·4CH3CONH2·5H20－H2O was plotted．The temperature of the eutecticpoint is at－34．5℃ containing the ternary compound 61．3％． Theternary compound Is congruentlysoluble In water covering the tempera－ture range from the eutectlc point to its melting point．
    A STUDY ON THE THERMOSTABLE STATIONARY PHASES FOR GAS CHROMATOGRAPHY(Ⅰ)——THE USE OF TETRAPHENYLPHENYL TRIETHOXYSILANE AS STATIONARY PHASE
    Yan Changtai, Lu Maosun, Tang Hongmao
    1983, 4(4):  428-432. 
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    Tetraphenylphenyl triethoxysilane and its hydrolysate and pre polymer were synthesized. The stationary phase was obtained by (1) dissolving the hydrolysate or prepolymer in benzene and then coated on the diatomaceous supports, and (2) the coated support was heat-treated at 400℃ under a stream of nitrogen for 12 hours. The characteristics of the prepared column were, (l) A mixture of n-alkanes contaning C7-C30 has been well separated when the temperature was programmed to 320℃. (2) n-C16H34 could be dertermined quantitatively. (3)Maximum temperature of 320℃ has been used without bleeding. (4) The number of HETP was 700 plates per meter approximately.The effects of the surface properties of the supports, of the quantity of the hydrolysate or prepolymer used in preparing the stationary phase, and of the temperature and period of heat-treatment on thecharacteristics of the column are discussed.
    THE COORDINATION REACTION OF SOME ASYMMETRICAL BISAZO DERIVATIVES OF CHROMO- TROPIC ACID WITH RARE EARTH ELEMENTS
    Ma Yongfu, Ni Zhao'ai
    1983, 4(4):  433-438. 
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    The coordinating behavior between 18 asymmetrical bisazo derivatives of chromotropic acid containing the auxochrome-COCH3, -NO2, -SO3H and rare earth elements has been investigated. The influences of the auxochrome-COCH3,-NO2,-SO3H and their substitutive position on the 'properties and the composition of the chelates have also been discussed.
    Preface
    STUDY ON THE POLAROGRAPHIC CATALYTIC WAVE OF COBALT IN ETHYLENE DIAMINE-NITRITE SOLUTION
    Li Nanqiang, Wang wenxi, Zhao Kaiyuan
    1983, 4(4):  439-443. 
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    In a supporting electrolyte containing 0.04-0.lM ethylene diamine, 0.4-l.0M NaNO2 and at pH11, we obtained a sensitive polarographic catalytic wave of cobalt. The catalytic wave is in a peak shape withpeak potential between -1.2-1.3V (SCE). The limits of detection ofdc and single-sweep polarography for cobalt are 5×10-9M and 5×10-10M respectively.The method has been applied to the determination of cobalt in nickel salts.It is confirmed that in the compact layer of electrical double layer the associated ion pair [(Co(en)3)2+·NO2-]+ results in the formation of catalytic wave. The overall electrode reaction may be represented as follows: where E1＞E2
    Articles
    THE STUDY OF THE REACTIONS OF TWO TYPES OF NEW COLOR REAGENT P-ACETYL-ARSENAZO WITH RARE EARTHS
    Zeng Shengnian, Cai Ruxiu, Yu ximao, Zeng Yun'e
    1983, 4(4):  444-448. 
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    p-acetyl-arsenazo is a new color reagent for spectrophotometry determination of rare earths. In the medium of HCl-NaAc, it forms α-type of complexes with Ce-group rare earths. It is highly sensitive and selective: ε670=(10.3-11.6)×104(La-Nd).The complexes are very stable. The Beer's law is obeyed from(0-70)μg/25ml (La-Nd, oxide). This reagent has been used to determine micro Ce-group rare earths in alloy steel by direct spectrophotometry.Under a certain experimental condition, the a-type of rare earths complexes (La-Nd) can be converted to β-type, λmax = 730nm. The tendency of the conversion of complexes decreases as the atomic number increases, which can enlarge the difference between Ce-group rare earths. The a-type complexes converted to β-type can be influenced by the reaction medium, the acidity, the molar ration of [RE]/[R], the standing time,the organic solvent and others.In this paper the color reactions of two types of rare earths with p-acetyl-arsenazo and the conditions of conversion have been studied. The composition of complexes of two types have been determined.
    THE POLAROGRAPHIC CATALYTIC WAVE OF COMPLEX OF Ga AND CUPFERRON
    Zhang Shuyun, Xu Keli
    1983, 4(4):  449-452. 
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    In this paper, the oscillopolarographic behaviour of the adsorptive catalytic wave of Gallium has been studied. It is found that Ga can be determined from the height of a catalytic wave at -0.92 (vs. SCE) in the formic acid and ammonium formate buffer solution with cupferron. The optimum conditions are 0.15M HCOOH, 0.05M HCOONH4, 8.0×l0-5M cupferron and pH = 2.6-3.0. The calibration graph covers the range 7.2×10-8M-3.6×10-8M-Ga. The nature of the catalytic wave was considered to be the adsorptive complex wave of Ga with cupferron.
    SPECTROPHOTOMETRIC STUDY OF THE MIXED-LIGAND COMPLEX SYSTEM Zr(Ⅳ)-EDTA- STILBAZO AND ITS APPLICATIONS
    Wang Dongjin, Lin Chao, Lin Xing
    1983, 4(4):  453-457. 
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    A ternary complex of Zr(Ⅳ )-EDTA-Stilbazo has been investigated and found to be a highly selective system for the spectrophotometric determination of Zr(Ⅳ). Zirconium (Ⅳ) forms an orange-red coloured ternary complex with Stilbazo and EDTA at pH 5.6-6.6. The complex exhibits maximum absorption at 503nm, where the apparent molar absorptivity is 2.8×104. The molar ratio of the three components in the complex is estimated to be Zr(Ⅳ) :EDTA : Stilbazo = 1: 1: 1 by the Job's method and molar ratio method. Beer's law is obeyed in the range of 0-50μg Zr/25ml.A highly selective method has been developed for the rapid determination of micro amounts of zirconium in nickel-base alloy and Al-Mg alloy without separating Zr from the accompanying elements.The results are satisfactory.
    SYNTHESIS OF ALLYL BENZOCROWN ETHERS
    Chen Yuanyin, Yuan Guangpu
    1983, 4(4):  458-462. 
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    In this paper we describe a convenient route to synthesize allyl benzocrown ethers. Monoetherification of catechol with allyl bromide followed by Claisen Rearrangement produced 3-allyl-catechol and 4-allyl-catechol. Treatment of allylcatechols with а, ω-dihalopolyethyle-neglycols led to allyl benzocrown ethers. Thus, by this method, we prepared two new crown ethers, 3-allylbenzo-15-crown-5 and 4-allyl-benzol5-crown-5. Their structures were identified by the data of elemental analysis, IR, MS and PMR spectra. The complex capacities of the above crown ethers for sodium and potassium picrate were determined, and, also, the behaviour of PVC membrane electrodes containing them as active materials was investigated.
    RING CLEAVAGE REACTION BETWEEN POLYACETOXYSILANES AND EPICHLOROHYDRIN
    Xie Qinglan, Yang Xueru, Wang Suhua, Wang Jitao
    1983, 4(4):  463-468. 
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    The ring cleavage reaction between polyacetoxysilanes and epichloro-hydrin using 5-tert-butyl-2-furanatochromium(Ⅲ) as a catalyst was studied in detail and the corresponding products containing both acetoxy and substituted isopropoxy groups were obtained. The distribution of the products of the reaction depended on the molar ratio between polyacetoxysilanes and epichlorohydrin. IR of the products showed that the reaction between the reagents was stepwise; after the first acetoxy group reacted with the epichlorohydrin, the second and third acetoxy groups with subsequent mole of epichlorohydrin successively.
    STUDIES ON NITROXIDES (Ⅴ)——THE EFFECT OF 4-SUBSTITUENT ON THE ESR hfs CONSTANTS OF PIPERIDINE NITROXIDES
    Liu Youcheng, Liu Zhongli, Wang Yukun
    1983, 4(4):  469-475. 
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    Six differently 4-substituted 2, 2, 6, 6-tetramethylpiperidyl-N-oxides were synthesized and their ESR hfs constants aN determined in n-hexane and glycol respectively. It is shown that an approximate linear correlation between αN and Pauling's electronegativity x of the 4-substituent is present for both solvents, but the slopes of the αN-x straight lines are very different. Based on the EHMO calculations it is proposed that the effect of 4-substituent on aN may be caused by a kind of field effect which affects the spin density (i. e., the electron distribution in the frontier orbital) and the "out of plane angle" (i. e., the hybridization of the N atom). The solvent effect is explained in terms of the EHMO calculations, too.
    THE REACTION BETWEEN (C6H5COCHCOC6H5)2- EuOCOCH3 AND C5H5Na
    Zhu ShenJie, Tan Hai'an, Yang Ruihua, Kao Chenheng
    1983, 4(4):  476-480. 
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    A new compound with high thermal stability is obtained from the reaction between (C6H5COCHCOC6H5)2Eu·OCOCH3 and C5H5Na. It is sensitive neither to O2 nor to H2O.The results of elemental analysis, molecular weight determination, UV and IR spectra of the product are given. The molecular structure of the product is suggested to be (C6H5COCHCOC5H5)2Eu-(η'C5H5).
    ENRICHMENT OF LITHIUM ISOTOPES BY HIGH PRESSURE ION EXCHANGE DISPLACEMENT CHROMATOGRAPHY (Ⅱ)——CALCULATION OF HETP AND ERICHMENT CONDITIONS
    Ling Daren, Zheng Zuying, Yue Tingsheng, Yang Kungshan, Wang Yani, Xu Huiqun
    1983, 4(4):  481-486. 
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    This paper describes a new method of calculating the height equialent to a theoretical plate (HETP) from the value of the total enrichment of the species to be enriched in the unsteady band (E'e) according to the equilibrium theory of the distillation type used for enriching isotopes. From this, the quantitative relations between the total enrichment and the experimental parameters are established.The results show it is favorable for reaching a high enrichment degree for a short time if the conditions with low concentration of eluent, high linear flow rate and long adsorption band are adopted for enriching lithium isotopes and that Glueckauf's theory and Snyder's formula are also suitable for light isotopes enrichment process with simple displacement mechanism.In this connection, 0.079M CaAc2 is chosen as the eluent, 9.9cm/min as the linear flow rate and 2.35m as the length of lithium band with the natural abundance. After the band is eluted under these chosen conditions for about 140m (17days), the quantities of lithium isotopes at the edges of the band reach up to 97.5% in 7Li and 15.8% in 6Li respectively.
    A SCF-Xα-SW STUDY OF SOME MODEL BIOLOGICAL COMPLEXES
    Zhu Ji-Kang, Pan Yuh-Kang
    1983, 4(4):  487-492. 
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    The different roles of the three metal atoms in biology have been studied preliminarily. The model complexes [(C2H2X2)2Me]n with central atom Me=Be, Mg, Zn, liganding atoms X = O,S and the charges of the complexes n=+2,0,-2 are studied by SCF-Xα-SW method. The results show that the complexes with different metals have different structures of one-electron eigenvalue and eigenfunctions. The complexes with central atoms Be have highest density of states, highest electron negativity and widely spreaded molecular orbitals nearby Fermi energy levels. The charges of the three metal atoms in the complexes with liganding atoms X=S are quite different. The charges of Mg are biggest, the charges of Be medium, Zn nearly zero. Probably it hints some relation between diffrent roles of the three metal atoms in skin and different charges of the atoms in the sulfur complexes.
    Preface
    A STUDY ON KINETICS OF DEHYDRATION PROCESS OF LANTHANUM, PRASEODYMIUM, NEODYMIUM, SAMARIUM CHLORIDE HYDRATES
    Gong Zheng, Chen Peiheng, Guo Zhizhen, Ma Jinhua, Chen Yunsheng
    1983, 4(4):  493-498. 
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    A fast and simple method for establishing the reasonable kinetic function of the titled process, g(α) was presented. This consists of.(1) Choosing more possible ones(may be 2 or more) graphically, and calculating corresponding activation energy E by using the following formula:(β: heating rate, R: gas const., T: temperature K) (2) Calculating the activation energy by the following formula at a given a value:(3) Comparing the different values of E obtained in (2) with those obtained in (1) and considering. the rationality, of frequency factor A and thus deciding which g(α) is more reasonable.The kinetic equations, the corresponding parameters and the mechanism of dehydration processes of titled hydrates in vacunm and nitrogen gas had been determined and disccused.
    Articles
    CARRIER EFFECT IN SUPPORTED PLATINUM CATALYSTS
    Yang Xiyao, Ren Shading, Pang Li
    1983, 4(4):  499-503. 
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    The interaction between Pt and carriers SiO2, SiO2-Al2O3, Al2O3, SiO2-SnO2 and Al2O3-SnO2 was investigated by TPD and HOT method. It was shown that the order of the Pt-carrier interaction strength is Al2O3>SiO2-Al2O3>SiO2; It was found too that the oxide of Sn Possesses the action to strengthen the carrier effect of SiO2 and Al2O3. On this basis, we suggested that the site of the Pt-carrier stronger interaction may be the surface complex of Pt and oxygen-dificient oxides Pt-(Al2Ox) and Pt-(SnOx).
    AGGREGATION OF ION PAIRS (Ⅰ)——SOLVENT AND ANION EFFECT ON THE AGGREGATION
    Shen Yusheng, Liu Xiyu, Liu Jinjun, Liu Xiujie
    1983, 4(4):  504-506. 
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    The average aggregation number (A) of tetrabutylammonium halides in organic solvent has been determined ebulliometrically. A of tetrabutylammonium bromide in benzene is much larger than that in chloroform (Fig.1), it seems that the polarity of the solvent is the major factor.In chloroform, A decreases in the order: iddide>bromide>chloride (Fig.2).When the quaternary ammonium salts exist as mixtures under phase-transfer reaction conditions, and A of the mixed bromide and iodide is determined and is found larger than each alone when there were no interaction between different ion pairs. We consider the ion pairs existing as mixture aggregate (see Table).
    RELATIONSHIP BETWEEN ADSORPTION CHARACTERISTICS OF AMMONIA ON H-MORDENITE AND ITS CATALYTIC ACTIVITY
    Yang Kongzhang, Zhao Hui, Xu Peili, Zeng Tianshu
    1983, 4(4):  507-511. 
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    Adsorption characteristics of ammonia on H-mordenite (HM) at various temperatures have been studied by IR spectra and .differential thermal techniques. The relative amounts of reversible and irreversible adsorption of ammonia and their changes with temperature are measured. Moreover, IR spectra of ammonia on HM and its catalytic activity for toluene disproportionation reaction are determined under conditions approximating those that are actually carried out for this. Experimental results show that the adsorption of ammonia on L-site is reversible, but that on B-site is irreversible. It has been proved that B-site is the catalytic active center for toluene disproportionation reaction.It seems that under our experimental conditions L-sites do not play a direct role in disproportionation reaction
    KINETIC INVESTIGATION AND REACTIVE SPECIES IN ANIONIC POLYMERIZATION OF BUTADIENE INITIATED BY n-BUTYLLITHIUM/TETRAHYDROFURAN
    Gao Zhanxian, Gu Mingchu, Ying Shengkang
    1983, 4(4):  512-516. 
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    In the present paper the reaction rate of polymerization of butadiene initiated by buiyl lithium and tetrahydrofuran was investigated and the micro-structure of polybutadiene was determined. The reactive species in the system were also discussed. The relationship of polymerization rate with respect to the concentration of the monomer was obtained: second order in the induction period and first order in the propagation period. The reactivities of the active species were evaluated and the contribu-tion of different reactive species to reaction rate and micro-structure of the polymer was also resolved.
    STUDIES OF THE DYNAMIC MECHANICAL BEHAVIOR OF POLYPHENYLENE SULFIDE
    Zeng Hanmin, He Guoren
    1983, 4(4):  517-522. 
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    By using the torsional braid analysis (TBA), We have investigated the dynamic mechanical behavior of polyphenylene sulfide (PPS). The experimental results showed that a variety of factors have effects on the dynamic mechanical behavior of PPS with different molecular weight and end groups. These factors include the modes of heat treatment (solid-state Curing or melt-state curing), heating time, heat history of Samples (quenching or annealing) and the surface properties of fibres which were used as braids (glass fibre, carbon fibre, and graphite fibre, or their surface treatment). The changes in dynamic mechanical characteristics are associated with the variation of the molecular structure and supermolecular structure of PPS caused by the factors mentioned above.
    STUDIES ON REGULARITY OF AMINO ACIDS REPLACEMENT IN HOMOLOGOUS PROTEINS (Ⅰ)——CQNFQRMATIONAL ANALYSIS OF INSULINS FROM DIFFERENT SPECIES
    Cheng Yuhua, Zhang Xuezhong, Tong Xiangshan
    1983, 4(4):  523-528. 
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    In this article the regularity of amino acid replacement among ho-mologues insulins was explored. It is shown that the reservational mutants are developed along no-random way: in the rigit structures of protein, replaced amino acids possess similar conformational parameters; a(?)varied side of α-helix frequency of replacement of amino acids is different from each other.
    STUDIES ON CONSTRUCTION OF THE PVC-BASED MEMBRANE TETROCHLOROFERRATE (Ⅲ) ION-SELECTIVE ELECTRODE
    Gong Hongzhong, Zhu Yuanbao, Zeng Yunlong, Ou Yungui
    1983, 4(4):  529-531. 
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    Seven tetra-alkyl ammonium salts have been tested as the electro-active material for the PVC-based membrane tetrachloroferrate(Ⅲ) ion-selective electrodes. The electrode based on the tetrachloroferrate (Ⅲ) salt of trioctylhexadecylammonium as the electroactive material was considered to be the best. At 25℃, the electrode shows Nernstian response for tetrachloroferrate (Ⅲ) ion over the concentration range from l×10-2M to 7×10-6Miron (Ⅲ) with a slope of 60mV/pFe.The detection limit is down to 2.5×10-6M iron (Ⅲ) in the 5M NaCl-0.05 MHC1 solution. Sn4+, Hg2+, Cd2+ and Zn2+ in a more or less extent interfere. The possibility of determination of iron (Ⅲ) in solutions of high Cl- concentration has been discussed.
    THE ADSORPTION OF THIOUREA AND DIPHENYTHIOUREA ON MERCURY- ELECTROLYTE INTERFACE
    Zhou Zhuoxiang, Chao Jinlan
    1983, 4(4):  532-534. 
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    The a.dsorption of thiourea . (TU) and diphenythiourea (DPTU) on mercury has been investigated by interfacial tension measurements in aqueous solution and aqueous methanol. The maximum potential of electro-capillary curve shifts toward negative as TU or DPTU concentration increases. It is assumed that the negative parts (S atom) of the molecules facing the mercury surface are adsorbed resulting in a linear relation between Δφs=0 and lgC. If the mercury stirface charge density equals to ε, the adsorption isotherm of TU. can be calculated by the follwing equation. Γ=-1.44×10-10lgC + (4.45 + 0.19ε) × 10-10
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