STUDY ON DETERMINATION OF TRACE Cu（Ⅱ） BY DDCT CHELATING RESIN PRECONCENTRATION AND THIN LAYER RESIN PHASE SPECTROPHOTOMETRY

A new method for determination of Cu(Ⅱ) by DDCT chelating resin preconcentration and thin layer resin phase spectrophotometry was developed. The method has a high sensitivity (ε435 =3.6×105 L/mol· cm), which is 33 times higher than that of liquid phase spectrophotometry. It has a good selectivity (most coexisting ions could not influence determination) and an ideal precision [30μg Cu(Ⅱ), n=6, RSD= 1.67%]. The content of Cu(Ⅱ) in water, high purity rare earth and its oxide was determined. The detection limit of Cu(Ⅱ) is 5.3μg/L, and the linear range is 0～7.2 μg/ml. The result is satisfactory.     

STUDY ON DETERMINATION OF TRACE Fe BY Fe(Ⅱ)-VA THIN LAYER RESIN PHASE SPECTROPHOTOMETRY

1. INTRODUCTION Since the solid spectrophotometry was first mentioned by Jiyong in 1976, the solid spectrophotometry has been widely concerned by analytical chemists because it incorporate concentration, separation and determination, has a high sensitivity (which is 10~100 times higher than that of liquid phase spectrophotometry) and has a good selectivity. In solid spectrophotometry, the resin phase spectrophotometry is used widely [1~10]. But traditional spectrophotometry need a special…     

STUDY ON DETERMINATION OF TRACE Fe BY Fe（Ⅱ）-VA THIN LAYER RESIN PHASE SPECTROPHOTOMETRY

A new method for the determination of Fe by thin layer resin phase spectrophotometry in alkali condition was reported. The complex anion formed by Fe(Ⅱ) and VA was absorbed on the 717#resin and Fe was determined by making thin layer. This method had a high sensitivity (ε620=3.0×105 L/mol·cm), which was 15 times higher than that of liquid phase spectrophotometry. It had been proved a satisfactory precision (5.0μg Fe, n=6, RSD=1.8%). The trace Fe in natural water was determined and the recovery was 97%.     

STUDY ON THE DETERMINATION OF TRACE Fe（III） BY THIN LAYER RESIN PHASE SPECTROPHOTOMETRY

A method to determine Fe（Ⅲ） by thin layer resin phase spectrophotometry has been developed in this paper. The colored complex formed by Fe（Ⅲ） and 1,2-benzendiol is concentrated on the 717^# resin, then Fe（Ⅲ） can be determined directly by making thin layer. The method is sensitive with a apparent molar absorption of 4.8×10^4L/mol.cm, which is 16 times higher than that of liquid phase spectrophotornetry, most coexisting ions do not influence the determination. The detection limit for Fe（Ⅲ） is 1.47μg/L with the precision of 3.3% [n=6, 7μg/50mL Fe（Ⅲ）]. The calibration curve is linear in the range of 0-25μg/50mL. The preposed method was applied to the determination of Fe（Ⅲ） in water sample with satisfactory results.     

STUDY ON THE DETERMINATION OF TRACE BISMUTH(III) BY THIN-LAYER RESIN PHASE SPECTROPHOTOMETRY

1.INTRODUCTIONThinlayerresinphasespectrophotometryisanewanalyticalmethodinthefieldofspectrophotometricanalysis;ittakesitssourceattheliquid-liquidextractiontechniquesincombinedwithclassicalspectrophotometricanalysis.Thesubstanceofproposedmethodisaccordingtounderprinciplesthatthetargetmetalionswasassociatedwithsomeligandsinaqueousphase,thentoformedaternaryormulticomponentcomplexions,suchasanioncomplexes.Aftertheassociationreactionwasfinished,thecomplexionswillassociatedwithaion-exchangeresin…     

STUDY ON THE DETERMINATION OF TRACE BISMUTH（III） BY THIN-LAYER RESIN PHASE S PECTROPHOTOME TRY

In this paper, a new thin-layer ion-exchange resin phase analytical method is introduced. It is based on that, the bismuthous cation can associate with iodic anions, so as to formed an anion complex [BiI4-_] in a strong acidic environments. This anion complex can also exchanges with a weaker anions on the surface active site of anion exchange resin, so that a[R+] [Bil4-] solid phase binary associational system is produced. Owing to the solid system is a great many dispersive particulates, it can be pressed to a thin-layer by press tools of the so called “thin-layer resin phase “ or “resin phase “, and using this solid association system spectrophotometry for the determination of trace metals. So it can increase the analytical sensitivity. This association system exhibits maximum absorbance at 460nm, and obeys Beer‘s law over the concentration range 0.0lug/ml-l.20ug/ml of bismuthous(lll), h has a molar absorptivity of 7.1×l^5 [L/mol.cm]. it indicated the resin phase spectrophotometry is a sensitive analytical method for trace bismuthous. It is 18 times higher than routine aqueous spectrophotometry. The relative standard deviations is 1.82% (n=6) for the F fmeasurements of 0.Sug/ml Bi(llO. The detection limit of Bismuthous(lll) is 1.4 XlO~mol/L. The method has applied to the analysis Bi(lll) in environmental water samples.     

PRECONCENTRATION OF TRACE ZINC IN SEAWATER ON CPPI RESIN BY FIA AND ON-LINE DETECTION BY ICP-AFS

A quite new type of chelating resin CarboxymethylatedPolyethylenimine-Polymethylenepolyphenylene Isocyanate(CPPI)is usedfor the preconcentration of Zn from high salt water such as seawater.The preconcentration is controlled through the technique of FlowInjection Analysis(FIA).The concentrated sample solution is thendirectly transferred to an Inductively Coupled Plasma-AtomicFluorescence Spectrometer(ICP-AFS)for determination.The detectionlimit of Zn by the technique is about 0.06 ppb.     

STUDY ON THE KINETICS OF POLYMERIZATION OF MMA BY COPPER (Ⅱ) CHELATING RESINS

The polymerization of MMA initiated by copper (Ⅱ) chelating resins/CCl4 system was studied. From the kinetic data, the kinetic equation of polymerization can be expressed asRp = Ke-56400/RT[MMA]1.57[CCl4]m[RESIN-Cu]0.18where m:3-4. 5,when [CCl4] 0. 1-6. 93M. The free radical polymerization mechanism is proposed. The primary radicals are formed by the process of complexation-chlorine transformation among the copper(Ⅱ)chelating resin,CCl4 and methacrylate.     

DETERMINATION OF COMPOSITION DISTRIBUTION OF SEGMENTED POLYURETHANES BY THIN LAYER CHROMATOGRAPHY

The compositional heterogeneity has been studied for a series of PCL/MDI/BDO segmentedpolyurethanes. Their average hard segment content measured by NMR method was ranging from17% to 42%. Macromolecules of segmented polyurethanes can be separated according to theircomposition by TLC technique with a mixed solvent of toluene/acetone/ tetrahydrofuran as the devel-oper. A dual wavelength TLC spectrodensitometer was used for quantitative analysis of TLC results,and method for data treatment is proposed to obtain the composition distribution with no need ofany reference samples as TLC elution standards. The polyurethane samples are found to be hetero-geneous in composition, having bimodal distribution curves.     

STUDY ON THE SYNTHESIS OF POLYSTYRENESUPPORTED MACROCYCLIC MERCAPTAL CHELATING RESIN AND ITS PROPERTIES

Chelating resin with macrocyclic mercaptal group supported on macroporous polystyrene beads was synthesized, which showed good selectivity to Hg~(2+): its complexing capacity amounted to 30—60 mg Hg~(2+)/g resin, two orders of magnitude greater than for other metal ions such as Ca~(2+), Zn~(2+), Cd~(2+), Pb~(2+) etc. This resin could restore the activity of urease which had been deactivated by poisoning with Hg~(2+). Its restoring power was far better than that of the mercapto-resin and common anionic exchange resins. It showed some promising use as an oral polymeric detoxifying drug for mercury poisoning.     

SIMULTANEOUS DETERMINATION OF NEODYMIUM AND PRASEODYMIUM BY ZERO-ORDER AND FOURTH-ORDER DFRIVATIVE SPECTROPHOTOMETRY

With derivative spectrophotometric method,the complexes oflanthanides with 2-(5-bromo-2-pyridylazo)-5-diethylaminophen-ol(5-Br-PADAP)in the presence of octylphenol poly(ethyleneg-lycol)ether(TX-100)were studied.It is found that the maximumabsorption of fourth-order derivative spectra of the neodymiumcomplex by 4f electron transitions is at 579(+)nm and 582(-)nmwith molar derivative absorptivities of 5.2×10~3 1.mol~(-1).cm~(-1).The maximum absorption of the zero-order derivative spectra ofthe complexes for neodymium and praseodymium is at 580hm,themolar absorptivities are 1.47×10~5 l.mol~(-1).cm~(-1)for Nd and 1.26×10~5 l.mol~(-1).cm~(-1)for Pr.The component ratio of the complexis Nd:5-Br-PADAP=1:4.Beer's law is obeyed in the range of0-3.75μg of Nd and Pr in 25ml of solution.The method has beenused for the simultaneous determination of Nd and Pr in foursynthetic samples and the results obtained are satisfactory.     

A STUDY ON THE TOUGHENING OF EPOXY RESIN BY HTBN-EPOXY RESIN PRECOPOLYMER

A novet toughened epoxy resin was obtained by using aprecopotymer of epoxy resin and hydroxy-terminated butadiene-acrylonitrilecopolymer(HTBN)and amine curing agent.The cured toughened resin hasexcellent mechanical properties due to the two-phase structure,which has beenobserved from SEM and TEM.     

STUDY ON THE KINETICS OF POLYMERIZATION OF MMA BY COPPER（Ⅱ） CHELATING RESINS

The polymerization of MMA initiated by copper(Ⅱ） chelating resins/CCl4 system was studied.From the kinetic data,the kinetic equation of polymerization can be expressed as Rp=Ke^-56400/RT[MMA]^1.57[CCl4]^m[RESIN-Cu]^0.18 where m:3-4.5,when[CCl4] 0.1-6.93M.The free radical polymerization mechanism is proposed.The primary radicals are formed by the process of complexation-chlorine transformation among the copper(Ⅱ) chelating resin,CCl4 and methacrylate.     

STUDY ON THE THERMODYNAMIC PROPERTIES OF ADSORPTION OF ETHYL BENZOATE AND DIETHYL PHTHALATE BY PHENOLIC RESIN ADSORBENTS

This paper presents experimental observations on the adsorption of individual solutes by a simple thermodynamic framework, and the equilibrium adsorption of ethyl benzoate and diethyl phthalate on phenolic resin adsorbent in hexane solutions within the temperature range of 293-313 K. The experimental results show that the Freundlich adsorption law is applicable to the adsorption of ethyl benzoate and diethyl phthalate on the adsorbent, since all the correlative factors R‘are larger than 0.99. The negative values of all the isosteric adsorption enthalpies for ethyl benzoate and diethyl phthalate indicate that they undergo exothermic processes, while their magnitudes (19-28 kJ/mol) manifest a hydrogen bonding sorption process. Other thermodynamic properties: the free energy changes and the entropy change associated with the adsorption have been calculated from the Gibbs adsorption equation and the Gibbs-Helmholtz equation.     

STUDY ON THE DECOLORIZATION OF D-RIBOSE ZYMOTIC FLUID BY RESIN ADSORPTION

1INTRODUCTIONWriboseisimPObotfortheactivitiesoflivingorganismsandcanbewidelyusedinpharmaceutical,foodandforageindustriesll.ZI.Itcanbeproducedbyfermentationofglucosewiththesubnutritionalmutantstrainoftheilliciumoill3.41.ruribosedemoticfluidhasacidicproperty,itScolorisdarkreddish.Itcontainsphosphateion,chlorideionandalittlequantityofsulfateionandoxalateion.Potassiumionandalittlequantityofsodion,calciumionandmagnesiumioncanalsobefound.Becauseofplentyofimpuritiesinthefluidandthedarkcoloroft…     

DETERMINATION OF BORON BY MICROWAVE PLASMA TORCH ATOMIC EMISSION SPECTROMETRY USING ON－LINE SEPARATION AND PRECONCENTRATION TECHNIQUE

ＤＥＴＥＲＭＩＮＡＴＩＯＮＯＦＢＯＲＯＮＢＹＭＩＣＲＯＷＡＶＥＰＬＡＳＭＡＴＯＲＣＨＡＴＯＭＩＣＥＭＩＳＳＩＯＮＳＰＥＣＴＲＯＭＥＴＲＹＵＳＩＮＧＯＮ－ＬＩＮＥＳＥＰＡＲＡＴＩＯＮＡＮＤＰＲＥＣＯＮＣＥＮＴＲＡＴＩＯＮＴＥＣＨＮＩＱＵＥ￥ＱｕｎＪＩＮ...     

DIRECT DETERMINATION OF NEODYMIUM AND ERBIUM IN RARE EARTH MIXTURE BY DERIVATIVE SPECTROPHOTOMETRY

The absorption spectra of 4f electron transitions of the complexes of neodymium and erbium with 8-hydroxyquinoline-5-sulphonic acid in the presence of diethylamine and ethanol have been measured by normal and third-derivative spectrophotometry. Their molar absorptivities are 70.7 l.mol~(-1).cm~(-1) for Nd and 62.5 l.mol~(-1).cm~(-1) for Er. They are 7.6 times and 14.9 times greater than those of corresponding chlorides, respectively. Use of the third-derivative spectra both eliminates the interference of Ce(Ⅳ) and increases the sensitivity for Nd and Er. Beer,s Law was obeyed from 0-10 ug/ml of Nd and Er. The method has been applied to the determination of neodymium and erbium in rare earth mixtures.     

STUDY ON ENRICHMENT AND SEPARATION OF TRACE ELEMENTS WITH SILICA GELS MODIFIED BY HETEROCYCLIC AZO DYES

Two types of modified silica gels were prepared by adsorption method and bonding method respectively. Enrichment and separation of trace metal ions have been done by using the column packed with modified silica gels.     

SYNTHESIS AND STRUCTURE OF Cu(Ⅱ)COMPLEXES BY OXIDATIVE ADDITION OF DIBENZOYL PEROXIDE ON METALLIC COPPER

Dibenzoyl peroxide undergoes oxidative addition on metallic copperpowder with 2,2′-bipyridine(or imidazole)in a mixed solvent(methanol andtetrahydrofuran),and affords the Cu(Ⅱ)complexes-[Cu(Ce(C_6H_5COO)_2(2,2'-bipy)]H_2O(1)and[Cu(C_6H_5COO)_2(C_3H_4N_2)_2](2).The structure was solved by direct methodsand Fourier synthesis.C_(24)H_(20)N_2O_5Cu (1),Mr=479.78,space group P2(1)/c,a=6.986(7),b=18.833(I),c=17.021(3),α=γ=90°,Z=4,V=2218.1~3,Dc=1.443g/cm\+3,R=0.055Rw=0.062.Complex(2),C_(20)H_(18)N_4O_4Cu(2),Mr=441.74,space group P2(1)/n,a=8.699(4),b=9.840(6),c=12.399(5),α=γ=90°,β=100.8°,Z=4,V=1010.9~3,Dc=1.654g/cm\+3,R=0.055,Rw=0.062.     

STUDY ON THE DECOLORIZATION OF D—RIBOSE ZYMOTIC FLUID BY RESIN ADSORPTION

In this paper,effects on of six type of resins the decolorization of D-ribose zymotic fluid have been studied for the first time.The results show that resin NKA-II has the best effect.the decolorization rage of D-ribose zymotic fluid is 91% at velocity of 1.0BV/hr and 25℃,the adsorption capacity can reach up to 5.7BV.The effects of adsorption conditions as well as conditions of resinregeneration on the resin decolorization capability were also studied.