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Table of Content

    24 August 1990, Volume 11 Issue 8
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    Articles
    The Formation of Paratungstate B and Its Use in the Separation of Tungsten and Molybdenum
    Jiang Anren, Jiang Weizhong, Pang Zhen
    1990, 11(8):  793-796. 
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    It is a very slow transformation from paratungstate Ainto Paratungstate B, nevertheless, it can be completed within several hours under the catalysis of silica. When the reaction finished, the pHvalue of the solution rose up to 8.1 from its initial value 6.7. Under the final pHcondition, no polymerization of molybdenum occured. The difference between the abilities of forming polyanions of between tungsten and molybdenum can be used for their separation. Adding guanidine to the solution containing tungsten and molybdenum, tungsten precipitated in the form of guanidine paratungstate B, while molybdenum remained in the solution as normal molybdate.
    Syntheses and Structures of Cr-ZSM-48 and V-ZSM-48 Molecular Sieves
    Jiao Qingzhu, Pang Wenqin
    1990, 11(8):  797-799. 
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    Cr-ZSM-48 and V-ZSM-48 type hetero-atom molecular sieves were synthesized and their structures were characterized by many physicochemical methods. The results show that Cr-ZSM-48, V-ZSM-48 and Silica-ZSM-48 are isostruclural. Cr and V exist as three-valence and four-valence ions respectively. The hetero-atoms are introduced into the framework of the molecular sieves in distortion-al tetrahedral coordination.
    Physico-Chemical Characterization of ZSM-5 Zeolite Synthesized Without Template
    Guo Zhenya, Wang Jingzhong, Wang Kaixuan, Zhou Daming, Xiang Shouhe, Li Hexuan
    1990, 11(8):  800-804. 
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    High resolution 29Si, 27Al, 23Na NMR is used to characterize the local structure of ZSM-5 zeolites with various Si/Al ratios synthesized without template. The dealumination from the framework of ZSM-5 zeolites treated at different temperatures and steaming times is studied by 29Si and 27Al MAS NMR. Asystematic X. R. D. study on the conditions under which the crystallographic shape of ZSM-5 type changes from orthorhombic to monoclinic(or vice versa) is reported.
    Studies on the Synthesis and Properties of Rare Earth Complexes with ADP and AMP
    Peng Zhouren, Li Yizhi, Wang Liufang
    1990, 11(8):  805-808. 
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    The preparation of RE( Ⅲ )-ADP (rare earth-adenosine-5'-diphosphate) and RE( Ⅲ )-AMP(rare earth-adenosine-5'-raonophosphate) (RE = Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) complexes possessing biological activities are first reported. The chemical compositions and trie properties of some of them have been elucidated on the basis of IR, UV, fluorescence, X-ray, elemental analysis and complexometric titratioh. The formulae of the complexes are [RE(Ⅲ)·(ADP)(H2O)3] and [(RE(Ⅲ)(AMP)2(H2O)4]H, respectively.
    Studies on Kinetics and Mechanism of Ternary Complex ——Sc-CAS-CTMAB System
    Lin Zhixin, Cai Ruxiu, Hu Keren, Fang Xianan, An Congjun
    1990, 11(8):  809-812. 
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    In the present paper, the absorption spectra in the CAS, Sc-CASand Sc-CAS-CTMABsystems were measured. According to equiabsorbance diagram the composition ratio;bf the ternary complex is Sc:CAS:CTMAB=1:2:2. By kinetics method the obtained results show that its rate equation is R=k[Sc(h)][CAS][CTMAB]-2. Referring to Eigen-Tamm mechanism a micelle-solvent cage mechanism is suggested. After the mechanism being treated by the equilibrium concentration method the rate equation is consistent with experimental results. The geometrical configuration of the ternary complex and reaction mode are also discussed.
    A Polarographic Study of the Formation of Ternary Mixed-Ligand Complex——Determination of the Stability Constant of Cd( Ⅱ )-Bipy-Gly Ternary System
    Kang Jingwan, Zhu Zhongping, Lu Xiaoquan, Chen Guangde, Oao Jinzhang, Bai Guangbi
    1990, 11(8):  813-816. 
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    The formation process and formation constants for binary systems Cd(Ⅱ)-2,2-bipyridyl (bipy), Cd(Ⅱ)-Glycine(Gly) and ternary system Cd(Ⅱ)-bipy-Gly were investigated by polaro-graphic method. We have also discussed the relations among various formation constants and their changeable rules.
    Studies on Luminescent Mechanism and Fluorescent Properties of Rare Earth Complexes ( I )——The Luminescent Mechanism of the Complexes of Samarium, Europium, Terbium and Dysprosium
    Hu Jiming, Chen Guanquan, Zeng Yun'e
    1990, 11(8):  817-821. 
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    In the present paper, the relation among the chemical properties, spectral properties and energy level of the complexes of samarium, europium, terbium and dysprosium were studied by using the laser induced fluorimetry. The model of energy transfer, rate equations and steady state solution in the complexes were established. According to Dexter's theory, the effects on fluorescent yield were discussed. Three elements of effective energy transfer from triplet state of ligands to rare earth ions were suggested.
    The Application of FIA with Air-Bubbles Sandwich ( I ) ——The Determination of Total Amount of a-Amino Acids in Tea
    Xu Yiyun, Sun Xiaoping, Wu Qiaozhen, Tian Liqing(Tian Li-ching)
    1990, 11(8):  822-824. 
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    The method of sample sandwiched between two air bubbles in FIA was used to determine the a-amino acids in tea. The hydra ted ninhydrin solution was added as a colour reagent and N2H4SO4 as a reductant. The use of N2H4SO4 instead of SnCl2 can accelerate the colour reaction and a higher sensitivity can be obtained. The detection limit can drop to 5 mg/La-amino acid. The reaction was carried out at 90 ℃ and the reaction time is reduced to 5 min. A small amount of TritonX-100 surfactant is used to keep the solution from depositing,thus a better reproducibility and a stable baseline can be obtained. In the measurement,the sampling frequency is 80 samples/h,the standard recovery is 97～106%, the related coefficient is about 0. 999 and the average relative standard deviation RSD is 2.8%.
    On Chemical Equilibrium by Kalman Filtering Spectrometry
    Li Zhiliang, Li Menglong, Shi Leming, Yu Ruqin
    1990, 11(8):  825-827. 
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    New methods based on the combination of spectrometry with Kalman filtering (KF) and factor analysis (FA) are proposed for investigation of chemical equilibria. Complex chemical equilibria are considered as special mixture systems with multicomponent in which there exist mutual equilibria among species in various media. Kalman filtering and factor analysis are used as an effective chemo-metrics resolution tool to extract the information from the spectral data. The number and concentrations of the existing species and the equilibrium constants between base and acid are estimated for some triphenylmethane (triaromylmethane) indicators or reagents.
    Studies on the Chemical Components of Centaurea Repens
    Zheng Shangzhen, Chen Hao, Shen Xuwei
    1990, 11(8):  828-831. 
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    Nine compounds were isolated from the plant of Centaurea repens. By means of IR, UV, NMR, MS analysis and chemical reactions, the structure of nine compounds were elucidated as I : n-Nonacosane; Ⅱ : 1-Docosanol; Ⅲ : 3-Stigmastanol; Ⅳ : β-Sitosterol; Ⅴ: Stigmast-7-en-3-ol; Ⅵ: Tetratriacontanoic acid ( β: 2, 4-bis(o-tolylazo)naphth-l-ol; Ⅶ: β-sitosterol-3-β-D-glucoside and Ⅷ: Apigenin-5-oβ-D-glucoside. Ⅶ was isolated for the first time from the natural product. Its spectral data were analyzed in detail. The structure ofⅦ was also proved by chemical synthesis.
    Preface
    Synthesis and Crystal Structure of a Bis-PPh3 Substituted Iron-Sulfur Cluster Complex(μ-n-C4H9S)(μ-CH3OCOCH2CH2S)Fe2(CO)4(PPh3)2
    Wang Ruji, Song Licheng, Wang Honggen, Hu Qingmei
    1990, 11(8):  832-836. 
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    Reaction of triphenylphosphine with(μ-n-C4H9S)(μ-CH3OCH2CH2S)Fe2(CO)6,whichwas prepared from a conjugated addition reaction of(μ-BrMgS)(μ-n-C4H9S)Fe2(CO)6 with,CH2=CHOCH3 followed by an alcoholysis process,gave the title complex of (μ-n-C4H9S)·(μ-CH3OCH2CH2S).The crystals of the title complex are monoclinic, spacegroup C2/c,with α=30.892(4)Å,b=12.454(2)Å,c=25.725(4)Å;β=91.46(1)°,V=9893.7Å3;Z=8;Dc=1.284g/cm3;R=0.060. The cluster core of this complex consists of twoiron and two sulfur atoms with a butterfly configuration. Two triphenyl phosphine ligands are trans to Fe-Fe bent bond. The substituents are attached to sulfur atoms by e-bonds.
    Articles
    Solid Phase Synthesis of the Human Trypsin Inhibitor
    Wang Ensi, Xu Jianping, Wang Zongmu, Li Wei, S. Funakoshi, H. Yajima
    1990, 11(8):  837-842. 
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    This paper describes synthesis of the human trypsin inhibitor (HTI) by the solid phase method in which both stepwise and segment condensation are involved. TMSOTf-thioanisol/TFA have been used as the agent which cleaves HTIfrom the resin and removes all of the side chain protecting groups simultaneously. Crude HTIwas purified by affinity chromatography on anhydro- trypsinr sepharose and reverse phase HPLC, the total yield is 6.3%. The resulting product shows powerful trypsin inhibitory activity that near 97% of the activity of natural HTI.
    Preface
    The Effectiveness Factor of Catalyst and Pressure Profile of Methanol for Oxidation of Methanol to Formaldehyde over Mo-Ce/SiO2 Catalyst
    Jin Yun, Yu Qiquan, Zhu Wenlian, Pang Li
    1990, 11(8):  843-847. 
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    The kinetics of oxidation of methanol to formaldehyde over Mo-Ce/SiO2 catalyst might be described by the equation of Redox mechanism with adsorption of methanol and.formaldehyde. When the particle size of catalyst reached 3 mm in diameter, intraparticle diffusion affected the reaction rate strongly. The effectiveness factors of catalyst were determined by experiments and interpreted by the approximation method of general rate equation.The pressure of methanol in catalyst pore might be obtained by equation .
    Articles
    Studies on Selective Catalytic Hydrogenation of Crotonaldehyde
    Xu Zhiluo, Zhang Jingwen, Jiang Yulin, Huang Huamin
    1990, 11(8):  848-850. 
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    The atmospheric catalytic hydrogenation of crotonaldehyde to butyladehyde was studied in the present paper. The P-2-Ni catalyst is very effective and selective for hydrogenation of unsaturated carbon-carbon band crotonaldehyde. The catalysts P-2-Co, P-2-Co-Ni were prepared for hydrogena-tion Of crotonaldehyde. The KX salt effect was researched in the reaction. The reaction conditions, temperature, solvents and the concentration of catalysts were selected.
    Effects of Temperature on Acidity of Zeolites
    Liu Xinsheng, Wu Tonghao
    1990, 11(8):  851-854. 
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    Effects of temperature on the acidity of zeolites were studied by using IRspectrometry. The experimental results show that the acidities (acid strength) of the zeolites are increased as temperature increases. The increase of the acidities of the diffrent -OH groups has the following order: acidic -OHgroups located in the big cavities (supercages in the zeolite Y and main channels in the ZSM-5) > Si-OH on the external surface or on the defect positions > acidic -OH groups located in the small cages (D-6 membered rings in the zeolite Y), The changes of the acidities are linear with increasing temperature over the temperature range employed in the study.
    Investigation on the Reduction of La1-xMxCoO3(M=Ca, Sr) Perovskite Oxides
    Wei Quan, Cui Wei, Guan Shiquan
    1990, 11(8):  855-858. 
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    The reduction of La1-xMxCoO3 has been studied by XPS and XRD. The extent of reduction of the perovskite oxides has been obtained as: La1-xSrxCoO3 > La1-xCaxCoO3> LaCoO3; for the same substitution cation, the extent of reduction increases with x. The reduction mechanism of La1-xMxCoO3 was discussed.
    Studies on Salt Effect in Solution by Gas-Liquid Chromatdgrapby
    Bai Tongchun, Lu Jinsuo, Zhou Xishun
    1990, 11(8):  859-862. 
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    Gas-liquid chromatography was developed to measure the salt effect coefficients (ks) of some solutes, such as hydrocarbons, aromatic-hydrocarbons, chloro-hydrocarbons, alcohols and ke-tones, in salt-containing solutions of sulfolane at 333.15 K. The experimental results show that the salt effect relationship for the most of solutes can be presented by Setschenow's equation; the properties of anions in the solution play a more important role for salt effect than those of cations; the charge transfer interaction of electrons from anions to 3d unoccupied orbitals of Cl in chloro-hydrocarbons has a notable impact on ks. Furthermore, the dependance of ks, on the alcohol structure at the absence of the alcohol self- association, and the difference of s between ketones and alcohols'are also investigated.
    Studies of Anionic Adsorption on the Surface of Polycrystalline Copper by Optical Second Harmonic Generation
    Pan Huifang, Bradley, R. A., Rojhantalab H. M., Richmond G., L.
    1990, 11(8):  863-867. 
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    Adsorption of anions on the surface of polycrystallirie copper of metal/aqueous solution interface was monitored with optical second harmonic generation (SHG). The SHGsignal is strongly affected by the anion adsorption on the surface. Excess charge density on the metal surface is concluded to be a major factor in the voltage-dependent production of the harmonic light. In this paper, the SHGintensity-voltage curves for polycfystalline copper in (0. 5 - x) mol/L NaClO4+x mol/L NaBr solutions for x in various values are presented. The results show that the perchlorate anion is quite weakly adsorbed at the surface and the halide ion is. a specific adsorption. The results demonstrate that the dominant feature in the voltage-dependent signal is a rise in harmonic light intensity with increasing halide ion concentration. In this case the metal-adsorbate interaction is a particularly clear manifest inthe SHG signal-voltage curves. The results of these studies show evidently that the SHG method Is aquite sensitive arid effective probe for monitoring adsorption quantitatively on the electrochemical interface.
    An In-situ FTIR Reflection-Absorption Spectroscopic Study of Adsorption and Orientation of Pyridine on Pt Electrode
    Zhang Jiujun, Lu Juntao, Cha Chuansin, Feng Zigang
    1990, 11(8):  868-872. 
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    The adsorption and orientation of pyridine on platinum electrode surface were studied by using cyclic voltammetry and in-situ FTIRreflection-absorption spectroscopy(SNIFTIRS). The experimental results obtained show that the adsorption of pyridine occurred over the whole potential range of -0.80～0.80 V(vs SCE). In the potential range of -0.80～0.20 V, pyridine rings were toproposed absorb in the direction perpendicular to the electrode surface in one or two different modes, while in the range of -0.20～0.8 V, the flat orientation was found to be predominant. The flat orientation of adsorption probably also weakened the ordering of water molecules at and near the electrode surface.
    Studies on Copolymers Crosslinked with Triallyl Isocyanurate ( Ⅱ )——Preparation, Structure and Properties of Saponified Copolymer
    He Binglin, Guo Xianquan, Yang Zhixin, He Dan, Shi Xiuping
    1990, 11(8):  873-876. 
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    The copolymers possessing hydroxy and carboxyl groups were synthesized by saponifying the copolymers of vinyl acetatg and triallyl isocyanurate, and the effect of different degree of cross-linked copolymers on the saponification was investigated. Pore structure parameters and swelling capacity of these saponified copolymers were also determined. The saponified copolymers were used as the stationary phase in gas chromatography. Their gas chromatographic properties are preliminary evaluated.
    A Study on the Curing and Toughening Effect of Terminal 2-Qxazoline Polyether on Epoxy Resin
    Wang Yumin, Pan Enli, Liu Guozhi
    1990, 11(8):  877-881. 
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    The curing reaction of epoxy resin with 2-oxazoline-terminated poly(propylene oxide) (active polyether) prepared by cyanoethylation and oxazoline. cyclization from hydroxy-terminated polyether is-studied by IR and DSC analysis. The apparent rate constants for different temperatures and apparent activation energy of the curing reaction are evaluated by DSC method. The mechanism of curing reaction is discussed. The physical and mechanical properties of cured epoxy system toughened by the active polyether with different molecular weights is estimated. The results show that via selecting the amount of polyether used and its MW, the cured systems may possess higher fracture toughness, while retaining the valuable properties of the rigid system. The active polyether can be used as a kind of latent-curing and toughening agent for epoxy resin.
    The Effects of the Degree of Substitution and Counterions on Thermal Behavior of CMC
    Huang Yuhui, Li Zuomei, Ma Zhiyi
    1990, 11(8):  882-886. 
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    The relationship of the crystallinity, glass transition temperature (Tg) and thermal stability of carboxymethylcellulose (CMC) with substitution degree (DS) from 0. 4 to 1. 55 were studied, by using WAXS, DSC and TGA methods. The crystallinities.rapidly decrease with the increase of DS. In the meanwhile, Tg of CMC also decreases with increasing DS, except the sample with DS=1. 55. The activation energies of the thermal degradation for the main chain of CMC lie between 251 and 293 kJ/ mol, similar to precursor cellulose. However, the initial temperature of the thermal degradation (Td) of CMC is influenced by the -CH2COONa contents on the chains, which increase somewhat with the increase of DS. This may be attributed to the interaction of metal ions and-carboxylate groups, on the polymer chains.The effects of counterions: H+, Na2+, Mg2+, Ca2+ and Al3+ on the crystallinity of CMC are quite different. The crystallinity decreases in either case when the radiis of counterions with the same valence increase or when the valences of counterions with the similar radius increase. The effects of the counterions on the thermal behavior of CMC are quite complicate, therefore only a preliminary discussion is presented.
    Effect of pH Values on Resonance Raman Spectra of Brilliant Yellow in Aqueous and CTAB Micella Solutions
    Zhang Yunhong, Tian Yongchi, Liang Yingqiu
    1990, 11(8):  887-888. 
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    Resonance Raman spectra of brilliant yellow (BY) in aqueous and cetyltrimethylammonium bromide (CTAB) micella solutions were measured at various pH values. Two spectral patterns under acidic and basic conditions are ascribed to correspond azo and quinoid forms of BY, respectively, which can be employed as a measure of the surface potentical and microenvironment of the micelle . According to Heeseman, the pKa= [pKa(surface) -pKa(aqueous)] is estimated to be about 0. 8 and is related to the change of the surface potential.
    Reduction of Nitriles with Combined Reducing Agent——Sodium Borohydride/Iron Salts
    Lin Ronghui, Zhang Yongmin, Zhou Zhiniu
    1990, 11(8):  889-890. 
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    Under mild conditions both aromatic and aliphatic nitriles were reduced to corresponding primary amines by combined reducing agent——sodium borohydride/ferric chloride in moderate yields. The effect of various solvents and metal salts on the reduction were studied. The reaction mechanism was also discussed.
    A Study on the Voltammetry of Palladium-a-Furil Dioxime System and Its Application
    Liu Gabyuan, Wang Shuyu, Sun Tianlin, Chen Rongli
    1990, 11(8):  891-893. 
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    In 0.065 mol/L Na2CO3/NaHCO3(pH 9.7) buffer solution containing 2.0× 10-6 mol/La-furil dioxime (FD),a sensitive complex wave of Pd( Ⅱ )-FD was observed by using linear sweep voltammetry. The peak height of the wave is directly proportional to the concentration of Pd ( Ⅱ ) in the range 1.1× 10-9-7. 5× 10-8 mol/L. The behaviour of the complex of Pd( Ⅱ ) with FD at mercury electrode was investigated in detail. The molar ratio of Pd( Ⅱ ) to FD is 1:2 . The apparent stability constant is 4. 9 ×1012. This method has been applied satisfactorily to the determination of trace palladium in ores.
    Selective Reduction Alkylation of Secondary Amine with Carbonyl Compounds
    Wang Ruo, Guan Yedi
    1990, 11(8):  894-896. 
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    Sodium hydrogen telluride was found to reduce secondary amines with carbonyl compounds to tertiary amines under mild conditions. The products of the reaction depend upon the nucleophilic character of secondary amines. As an application of this reduction, a new method for reduction alky-lation of secondary amines has been developed.
    Studies on the Selective Dehalogenation Reduction Reaction
    Guan Yedi, Hu Jie, Xiong Bo, Zhou Deling
    1990, 11(8):  897-899. 
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    Various halogen compounds were effectively reduced by sodium hydrogen telluride in aqueous solution or ethanol under mild conditions and in good yields, particularly when a molecule contains other groups such as carbonyl, carboxyl, ester and benzyl.The typical process occurred with a stbichiometric amount or a catalytic amount of tellurium. The mechanism may be envisaged that nucleophilic attack of hydrogen telluride ion (HTe-) on the a-car-bon atoms could lead to the leaving of the halogen from a-carbon atoms.
    Selective Hydroboration-Iodination of Terminal Alkenes Containing Ester Groups——Synthesis of Two Insect Sex Pheromones
    Pan Yijun, Xu Zhangbuang, den Jiawei, Jiang Jilong, Song Gongwu
    1990, 11(8):  900-902. 
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    Terminal alkenes containing ester groups are converted to w-functional alkyl iodides through a hydroboration-iodihation reaction blinder a mild condition; All Of the three alkyl groups on borane can be used in this case. The insect sex pheromones of Törtrix Viridana and Adoxophes Orana Rod are synthesized in a higher (Z)-form purity by using the w-functiori terminal alkyl iodides.
    Studies on Adsorption of Pyridine at AU Electrode by Modulated UV/Vis Reflection Spectrometry
    Lin Zhonghua
    1990, 11(8):  903-905. 
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    Both the dependence of relative change in reflectance on potential and the differential reflection spectra for Au electrode in both 0.1 mol/L NaFsolution and 0. 1 mol/L NaF, 0. 01 mol/Lpyridine solution have been measured respectively. The results show the a new band at 700 nm appeared after the surface atoms of the Au electrode were in a certain oxidized state during anodic polarization. It is assigned to charge-transfer band formed by the adsorbed pyridine molecules and the surface atoms of the Au electrode via the upper full ω-orbitals and the dangling bonds. The band was shiefted to 650 nm after the surface atoms of the Au electrode were in a higher oxidized state due to more anodic polarization.
    The Kinetic Study of Reactions of O(3p) with Propionaldehyde and Butyraldehyde
    Chen Congxiang, Zhang Jianxiang, Dai Jinghua, Yu Shuqin
    1990, 11(8):  906-908. 
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    The determinations of the rate constants of reactions of O(3p) atoms with propionaldehydeand butyraldehyde by discharge flow-chemiluminescence are presented. The results measured are asfellows: k=(9.0±0.4)×10-12·e(-994±17)/T (for propionaldehyde+O(3p))and k=(1.7±0.2)×10-11·e(-987±39)/T (for butyraldehyde + O(3p))The dissociation energies of C-Hbond of aldehydic group are derived from the kinetic results.
    The Experimental Studies of SERS of Coadsorptive System on the Electrochemically Roughened Silver Electrode Surface
    Gu Renao, Zong Yaping, Leng Yongzhang
    1990, 11(8):  909-911. 
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    This paper presents the studies of the SERS spectra and their potential dependence for pyridine and benzole acid adsorbed on the electrochemically roughened silver surface in the pyridine/ben-zoic acid/KCl coexistent system. Their adsorption manners on the silver surface were also studied. Ex- perimental results show that there exist eoadsorptive and competitive adsorption between pyridine and benzole acid on the silver surface in the coexistent system. The competitive adsorption and their manners vary with the changing of the applied voltage.
    A Research of the Structure of Macromolecule in Coal by X-Ray
    Zhang Daijun, Xian Xuefu
    1990, 11(8):  912-914. 
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    The high-angle scattering intensities from coals can be interpreted with a modle of a buckled sheet of a macromolecule in coal. Those which take part in the (hk) 2-dimensional interferred scattering, i. e. aromatic lamellae, only make up of a part of a macromolecule in coal. Amacromolecule in coal consists of a few aromatic layers through the cross-linking bonds of amorphous materials, such as, aliphatic materials, hydro-aromatic groups, five-ring structure etc.. With the increase of the rank of coals, the dimension of aromatic layers increases, and amorphous materials decrease.
    Studies on Adsorption of Polyacrylamide on Surface of Silica Gel and the Inhibition of the Adsorption
    Chen Jiushun, Tan Zhanjie, Meng Xiansheng
    1990, 11(8):  915-917. 
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    In this work an analytical measurement method was established for determining PAM adsorption isothermal curves in the extremely diluted solution, diluted solution and relatively concentrated solution respectively. The adsorption mechanism was also investigated preliminarily. The effects of several organic compounds and an inorganic salt (NaNO3) as the adsorption inhibitors on the adsorption of PAM on the surface of silica gel were studied. The results indicate that (1) PAM is strongly adsorbed on the surface of silica gel; (2) aminoethyl alcohol, morpholine and sodium nitrate are effective adsorption inhibitors.
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