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1989 Volume 6 Issue 2
1989, 6(2): 1-4
Abstract:
A more active and heat resistant water gas shift catalyst Co Mo K/Al2O3 has been obtained by modification of Al2O3 support with La2O3 (ranging from 0.5 to 1 wt.% based on the catalyst) and aftertreatment at 600℃. La-promoted catalyst lost~50% of its initial activity after water gas shift reaction which is accelerated at 500℃, while the unpromoted catalyst lost~70%. The activity of deteriorated catalyst can be restored by treatment with H2S/H2, but the rate of reactivation of the La-promoted is greater than that of the unpromoted. No obvious difference was found in the sulfidation of catalyst with H2S/H2 and temperature programmed reduction determination and pyridine adsorption on sulfided catalyst. XPS data indicated that a better dispersion of Mo and less Mo6+formed during water gas shift reaction on the La-promoted catalyst.
A more active and heat resistant water gas shift catalyst Co Mo K/Al2O3 has been obtained by modification of Al2O3 support with La2O3 (ranging from 0.5 to 1 wt.% based on the catalyst) and aftertreatment at 600℃. La-promoted catalyst lost~50% of its initial activity after water gas shift reaction which is accelerated at 500℃, while the unpromoted catalyst lost~70%. The activity of deteriorated catalyst can be restored by treatment with H2S/H2, but the rate of reactivation of the La-promoted is greater than that of the unpromoted. No obvious difference was found in the sulfidation of catalyst with H2S/H2 and temperature programmed reduction determination and pyridine adsorption on sulfided catalyst. XPS data indicated that a better dispersion of Mo and less Mo6+formed during water gas shift reaction on the La-promoted catalyst.
1989, 6(2): 5-10
Abstract:
In this paper the preparation of the binuclear complexes [C5H5Fe(CO)2]LnCl2·nTHF (Ln=Nd, Sm, Gd; n=1,2) and [C5H5Fe(CO)2][C5H4(SiMe3)]LnCl·nTHF (Ln=Nd, Sm,Gd; n=0,1,3) is reported. Both complexes were identified by clemental analyses, thermal gravimetric analyses, infrared spectra, mass spectra, NMR and EPR. The infrared spectral data reveal the bridging carbonyls between the iron and the rare earth elements.[C5H5Fe(CO)2]2Na·4THF as a reaction intermediate in the preparation of [C5H5Fe-(CO)2]LnCl2nTHF was characterized by crystal structural analyses.
In this paper the preparation of the binuclear complexes [C5H5Fe(CO)2]LnCl2·nTHF (Ln=Nd, Sm, Gd; n=1,2) and [C5H5Fe(CO)2][C5H4(SiMe3)]LnCl·nTHF (Ln=Nd, Sm,Gd; n=0,1,3) is reported. Both complexes were identified by clemental analyses, thermal gravimetric analyses, infrared spectra, mass spectra, NMR and EPR. The infrared spectral data reveal the bridging carbonyls between the iron and the rare earth elements.[C5H5Fe(CO)2]2Na·4THF as a reaction intermediate in the preparation of [C5H5Fe-(CO)2]LnCl2nTHF was characterized by crystal structural analyses.
1989, 6(2): 11-14
Abstract:
12-Tungstophospboric acid on active carbon (HPW/C) prepared by reflux adsorption was found to be highly effective for catalytic synthesis of diethyl ether. Under the optimum conditions the conversion of ethanol and the selectivity of esterification were 96% and 100% respectively. The high activity is attributed to high dispersion of HPW on active carbon which results in incrcase of the number of active sites or effective acid sites. The catalyst HPW/C is thermostable and HPW does not leak out of the Supports easily.
12-Tungstophospboric acid on active carbon (HPW/C) prepared by reflux adsorption was found to be highly effective for catalytic synthesis of diethyl ether. Under the optimum conditions the conversion of ethanol and the selectivity of esterification were 96% and 100% respectively. The high activity is attributed to high dispersion of HPW on active carbon which results in incrcase of the number of active sites or effective acid sites. The catalyst HPW/C is thermostable and HPW does not leak out of the Supports easily.
1989, 6(2): 15-18
Abstract:
The dielectric relaxation measurements for some AB crosslinked polymers based on castor oil were carried out as a function of temperature from -180℃ to 140℃ at different frequencies. The multiple relaxation and phase behaviors of AB crosslinked polymers were investigated with the dielectric spectroscopic analysis.The two components showed compatibility or near compatibility based on the dielectric relaxation spectra.The secondary relaxation was attributed to the local motion of the chain segments of polyurethane component. The interfacial polarization of the AB crosslinked polymers was described according to a method deduced in our laboratory.The activation energies of interfacial polarizaticn,which are related to the size of domains and the interfacial interaction between different components as well as the flexibility of the molecular chain in these samples, were calculated.
The dielectric relaxation measurements for some AB crosslinked polymers based on castor oil were carried out as a function of temperature from -180℃ to 140℃ at different frequencies. The multiple relaxation and phase behaviors of AB crosslinked polymers were investigated with the dielectric spectroscopic analysis.The two components showed compatibility or near compatibility based on the dielectric relaxation spectra.The secondary relaxation was attributed to the local motion of the chain segments of polyurethane component. The interfacial polarization of the AB crosslinked polymers was described according to a method deduced in our laboratory.The activation energies of interfacial polarizaticn,which are related to the size of domains and the interfacial interaction between different components as well as the flexibility of the molecular chain in these samples, were calculated.
1989, 6(2): 19-22
Abstract:
The inhibiting effect of 1,3,5-triphenylformazane(TFH) on the free radical polymerization of methyl methacrylate(MMA), initiated by AIBN, has been studied by dilatometric method.The results indicated that when TFH was incorporated with another inhibitors such as benzoquinone(BQ) or 1,4-naphtholquinone(NQ), the induction period of polymerization of MMA become longer than when TFH, hydroquinone(HQ) and p-tert-butylcatechol(TBC) was used alone. The results pointed out that when the mixture of TFH and chloranil(CA) in whatever proportion used, the induction period was shorter than when TFH used alone.Prec radicals TF· have been observed in the polymerization of MMA with added TFH.
The inhibiting effect of 1,3,5-triphenylformazane(TFH) on the free radical polymerization of methyl methacrylate(MMA), initiated by AIBN, has been studied by dilatometric method.The results indicated that when TFH was incorporated with another inhibitors such as benzoquinone(BQ) or 1,4-naphtholquinone(NQ), the induction period of polymerization of MMA become longer than when TFH, hydroquinone(HQ) and p-tert-butylcatechol(TBC) was used alone. The results pointed out that when the mixture of TFH and chloranil(CA) in whatever proportion used, the induction period was shorter than when TFH used alone.Prec radicals TF· have been observed in the polymerization of MMA with added TFH.
1989, 6(2): 23-29
Abstract:
The synthesis, characterization and structure of two noval coordination compounds,[Eu·HL2·(H2O)2]2·2H2O and [Tb·HL2·(H2O)2]2·2H2O (H2L=3, 4-furandicarboxylic acid), are reported. The compounds were characterized by IR, DTA, TG, DTG and fluorescence spectra. Two crystals are monoclinic with space group P2/c. The unit cell parameters are:a=10.842, 10.801; b=8.725, 8.664; c=16.366, 16.308Å;β=93.50, 93.67°;V=1545.3, 1523.0Å3; Z=2, 2 for Eu and Tb compounds respectively.
The synthesis, characterization and structure of two noval coordination compounds,[Eu·HL2·(H2O)2]2·2H2O and [Tb·HL2·(H2O)2]2·2H2O (H2L=3, 4-furandicarboxylic acid), are reported. The compounds were characterized by IR, DTA, TG, DTG and fluorescence spectra. Two crystals are monoclinic with space group P2/c. The unit cell parameters are:a=10.842, 10.801; b=8.725, 8.664; c=16.366, 16.308Å;β=93.50, 93.67°;V=1545.3, 1523.0Å3; Z=2, 2 for Eu and Tb compounds respectively.
1989, 6(2): 30-35
Abstract:
Fast atom bombardment (FAB) mass spectra of more than 10 lanthanide crown ether complexes were reported. A certain relationship was found between the intensities of ions in gas phase and their reactions in solution, that was coincident with the direct sputteting mechanism on FABMS. Therefore FABMS could be considered as a useful method to study solution reactions. FAB, linked scanning and MIKES/CID techniques were applied in this work.
Fast atom bombardment (FAB) mass spectra of more than 10 lanthanide crown ether complexes were reported. A certain relationship was found between the intensities of ions in gas phase and their reactions in solution, that was coincident with the direct sputteting mechanism on FABMS. Therefore FABMS could be considered as a useful method to study solution reactions. FAB, linked scanning and MIKES/CID techniques were applied in this work.
1989, 6(2): 36-39
Abstract:
The nucleation effect of some polyfunctional monomers on radiation crosslinking of low density polyethylene (LDPE) has been studied. The effect of monomer structure on the moiphological structure of LDPE and the relationship between radiation crosslinking and crystalline density of LDPE with different monomer were discussed according to the results of WAXD, TEM, DSC and gel fraction measurements. It is found that in the presence of monomer the crystalline content of LDPE was larger and the crystalline size was smaller than that of LDPE alone, and the greater the nucleation effect, the more accelerated the radiation crosslinking effect for LDPE. It is considered that both crystalline density and size are the primary (basis) factors in radiation crosslinking of crystalline polymers, and the crystalline damage caused by irradiation is closely relevent to the surface area between crystalline and amorphous regions of the polymer.
The nucleation effect of some polyfunctional monomers on radiation crosslinking of low density polyethylene (LDPE) has been studied. The effect of monomer structure on the moiphological structure of LDPE and the relationship between radiation crosslinking and crystalline density of LDPE with different monomer were discussed according to the results of WAXD, TEM, DSC and gel fraction measurements. It is found that in the presence of monomer the crystalline content of LDPE was larger and the crystalline size was smaller than that of LDPE alone, and the greater the nucleation effect, the more accelerated the radiation crosslinking effect for LDPE. It is considered that both crystalline density and size are the primary (basis) factors in radiation crosslinking of crystalline polymers, and the crystalline damage caused by irradiation is closely relevent to the surface area between crystalline and amorphous regions of the polymer.
1989, 6(2): 40-42
Abstract:
The crystal structure of the title compound was determined by X-ray diffractometry.The complex crystallizes in monoclinic space group C<2/c with Z=8. Lattice parameters are: a=25.747(5), b=8.461(0), c=17.407(3)Å and β=105.79(1)°. The structure was solved by Patterson and Fourier techniques and refined by least-squares to a final R value of 0.0283. The Zn(Ⅱ) ion is coordinated by three chloroligands and the atom N(1) of the pyrimidine ring of thiamine molecule, forming a slightly distorted tetrahedral coordination polyhedron. The average Zn-Cl distance is 2.266Å and the Zn-N bond length is2.042(4)Å.
The crystal structure of the title compound was determined by X-ray diffractometry.The complex crystallizes in monoclinic space group C<2/c with Z=8. Lattice parameters are: a=25.747(5), b=8.461(0), c=17.407(3)Å and β=105.79(1)°. The structure was solved by Patterson and Fourier techniques and refined by least-squares to a final R value of 0.0283. The Zn(Ⅱ) ion is coordinated by three chloroligands and the atom N(1) of the pyrimidine ring of thiamine molecule, forming a slightly distorted tetrahedral coordination polyhedron. The average Zn-Cl distance is 2.266Å and the Zn-N bond length is2.042(4)Å.
1989, 6(2): 43-47
Abstract:
Some methods were used to invetigate the crystalline behavior of low density polyethylene(LDPE) in natural rubber/LDPE blends. It was found that NR acted as a nucleation agent in the crystallization of LDPE. The crystallization rate of LDPE increased with theaddition of NR.
Some methods were used to invetigate the crystalline behavior of low density polyethylene(LDPE) in natural rubber/LDPE blends. It was found that NR acted as a nucleation agent in the crystallization of LDPE. The crystallization rate of LDPE increased with theaddition of NR.
1989, 6(2): 48-51
Abstract:
Two new complexes, LiBr·(CH2CH2O)5·H2O and CF3COOLi·(CH2CH2O)6·3H2O, were prepared and their in frated spectra(400-4000cm-1)were examined. The infrared study included a similar (CH2CH2O)5 complex of LiCl, and also similar (CH2CH2O)6 complexes of LiCl,LiBr and LiClO4, but with 5H2O, 5H2O and 2THF·3H2O respectively. Assignment of the various absorption bands was performed. Evidence was found for the splitting of the OH band due to two different modes of dentation(bridge and terminal) of the water molecule,and also for the splitting of the FCF2 and OCO bands due to the conformational transformation of CF3COO- while entering coordination.
Two new complexes, LiBr·(CH2CH2O)5·H2O and CF3COOLi·(CH2CH2O)6·3H2O, were prepared and their in frated spectra(400-4000cm-1)were examined. The infrared study included a similar (CH2CH2O)5 complex of LiCl, and also similar (CH2CH2O)6 complexes of LiCl,LiBr and LiClO4, but with 5H2O, 5H2O and 2THF·3H2O respectively. Assignment of the various absorption bands was performed. Evidence was found for the splitting of the OH band due to two different modes of dentation(bridge and terminal) of the water molecule,and also for the splitting of the FCF2 and OCO bands due to the conformational transformation of CF3COO- while entering coordination.
1989, 6(2): 52-55
Abstract:
The Pd loss from the polymer-bounded palladium catalyst in the selective hydrogenation of 1, 5, 9-cyclododecatriene at 100℃ and 1.96MPa hydrogen pressure has been studied.The effects of polymer supports on the Stability of catalysts were discussed. Pd dissolution was found to be decreased with decrease of pore radius of support. For the same polymer support,the stability of Pd was dependent on the atom i.e.O ≥N >P >C. An electron-donor group which linked with the ligand atom improved the stability of the catalyst. The more active and stable catalyst can be obtained when a five-member ring between Pd and the chelate ligand is formed.
The Pd loss from the polymer-bounded palladium catalyst in the selective hydrogenation of 1, 5, 9-cyclododecatriene at 100℃ and 1.96MPa hydrogen pressure has been studied.The effects of polymer supports on the Stability of catalysts were discussed. Pd dissolution was found to be decreased with decrease of pore radius of support. For the same polymer support,the stability of Pd was dependent on the atom i.e.O ≥N >P >C. An electron-donor group which linked with the ligand atom improved the stability of the catalyst. The more active and stable catalyst can be obtained when a five-member ring between Pd and the chelate ligand is formed.
1989, 6(2): 56-59
Abstract:
For the lincar calibration of the monodisperse polymer species using more than two polydisperse standards with known number-average MW, an effective and fast one-variable approach is deseribed. The equation ln M=A-BV containing only one variable B can be solved by the Newton's iteractive method, and the value of A is determined. The SEC (size exclusion chromatography) data of the characterized polyurethane samples were corrected for the chromatographic spreading and then used to demonstrate this computational procedure. The deviations of the number-average MW caculated by SEC from the results by osmotic msthed are acceptable.
For the lincar calibration of the monodisperse polymer species using more than two polydisperse standards with known number-average MW, an effective and fast one-variable approach is deseribed. The equation ln M=A-BV containing only one variable B can be solved by the Newton's iteractive method, and the value of A is determined. The SEC (size exclusion chromatography) data of the characterized polyurethane samples were corrected for the chromatographic spreading and then used to demonstrate this computational procedure. The deviations of the number-average MW caculated by SEC from the results by osmotic msthed are acceptable.
1989, 6(2): 60-62
Abstract:
The stereoselective borohydrogenation of 3, 5-cyclo-6-methoxyl-pregn-20(22) 5 by dicy-clohexylboronane to 20S-22-ol 1 was investigated.An appropriate ratio of sodium borohydride to boron trifluoride used in this reaction was given, and the structure of 3 unexpected products 6,7,8 obtained in this reaction was determined.
The stereoselective borohydrogenation of 3, 5-cyclo-6-methoxyl-pregn-20(22) 5 by dicy-clohexylboronane to 20S-22-ol 1 was investigated.An appropriate ratio of sodium borohydride to boron trifluoride used in this reaction was given, and the structure of 3 unexpected products 6,7,8 obtained in this reaction was determined.
1989, 6(2): 63-66
Abstract:
A new PVC lithium ion-selective microelectrode based on potassium tetraphenylborate (KTPB) or sodium tetraphenylborate (NaTPB) and plasticized by di-(n-octyl)-phenylphos-phonate (DOPP) has been constructed. The microelectrode based on KTPB has lower detection limit and better selectivity characteristics for bivalent ions, but the microelcetrode based on NaTPB has lower membrane resistance. The response characteristics of microelectrode for different concentrations in Li+ has been examined experimenetally in synthetic intracellular solution,serum and physiological saline.
A new PVC lithium ion-selective microelectrode based on potassium tetraphenylborate (KTPB) or sodium tetraphenylborate (NaTPB) and plasticized by di-(n-octyl)-phenylphos-phonate (DOPP) has been constructed. The microelectrode based on KTPB has lower detection limit and better selectivity characteristics for bivalent ions, but the microelcetrode based on NaTPB has lower membrane resistance. The response characteristics of microelectrode for different concentrations in Li+ has been examined experimenetally in synthetic intracellular solution,serum and physiological saline.
1989, 6(2): 67-68
Abstract:
Salicylaldehyde was obtained by electrolytic reduction of salicyclic acid. The apparatus and procedure recommended by Kobe has been improved. Under the conditions of 12-18℃,14-16A/dm2 salicylaldehyde with 96% purity can be prepared in 74% yield.
Salicylaldehyde was obtained by electrolytic reduction of salicyclic acid. The apparatus and procedure recommended by Kobe has been improved. Under the conditions of 12-18℃,14-16A/dm2 salicylaldehyde with 96% purity can be prepared in 74% yield.
1989, 6(2): 69-72
Abstract:
The kinetic study of the oxidative dehydrodimerization of propylene over the Bi-Ce oxide catalyst showed that the dimer formation reaction is first order with respect to the partial pressure of propylene and is zero order with respect to that of oxygen, while the formation of carbon dioxide is zeroth order and 0.35 order with respect to the partial pressure of propylene and to that of oxygen, respectively. It is considered that the dimerization and the complete oxidation of propylene take place on different active sites patallelly and the coupling of propylene is the rate-determining step, which is a result of the reaction between a gaseous propylene molecule and an adsorbed one on the catalyst surface (Eley-Ridsal type).
The kinetic study of the oxidative dehydrodimerization of propylene over the Bi-Ce oxide catalyst showed that the dimer formation reaction is first order with respect to the partial pressure of propylene and is zero order with respect to that of oxygen, while the formation of carbon dioxide is zeroth order and 0.35 order with respect to the partial pressure of propylene and to that of oxygen, respectively. It is considered that the dimerization and the complete oxidation of propylene take place on different active sites patallelly and the coupling of propylene is the rate-determining step, which is a result of the reaction between a gaseous propylene molecule and an adsorbed one on the catalyst surface (Eley-Ridsal type).
1989, 6(2): 73-76
Abstract:
The crystal and molecular structure of the title compound was determined from single crystal X-ray diffraction. The complex crystallizes in monoclinic space group P21/n with Z=2. Lattice parameters are: a=7.768(2), b=13.976(2), c=9.045(3)Å,β=113.12(3)°. The structure was solved by the direct method and Fourier techniques and refined full-matrix least-squares to R=0.035 for 1579 reflections. The Cu2+ ion is 6-ooordinte, being bonded to two oxygen toms from two unidentate nitrate groups and two nitrogen atoms and two oxygen atoms from two organic ligands. Each Cu2+ ion is coordinated In a distorted octahedral configuration.
The crystal and molecular structure of the title compound was determined from single crystal X-ray diffraction. The complex crystallizes in monoclinic space group P21/n with Z=2. Lattice parameters are: a=7.768(2), b=13.976(2), c=9.045(3)Å,β=113.12(3)°. The structure was solved by the direct method and Fourier techniques and refined full-matrix least-squares to R=0.035 for 1579 reflections. The Cu2+ ion is 6-ooordinte, being bonded to two oxygen toms from two unidentate nitrate groups and two nitrogen atoms and two oxygen atoms from two organic ligands. Each Cu2+ ion is coordinated In a distorted octahedral configuration.
1989, 6(2): 77-81
Abstract:
The solubilities of the ternary system,Yb(NO3)3·3H2O-B15C5-CH3OH, at 18℃ have been investigated by a modified semimcro phase equilibrium method through mesurement of the refractive indexes of the saturated solutions.The results showed that in the ternary system there is only one complex formed with composition of Yb(NO3)3·B15C5·3H2O·2CH3OH.which had been identified by thermal analysis. The molar ratio of ytterbium salt to water in complexes was found to be 1:3 in any preparation and there was the same molar content of organic molecule in complexes, i. e. 0.65 for all three solvents after the complexes were maintained till constant in weight indiscator with concentrated H2SO4.
The solubilities of the ternary system,Yb(NO3)3·3H2O-B15C5-CH3OH, at 18℃ have been investigated by a modified semimcro phase equilibrium method through mesurement of the refractive indexes of the saturated solutions.The results showed that in the ternary system there is only one complex formed with composition of Yb(NO3)3·B15C5·3H2O·2CH3OH.which had been identified by thermal analysis. The molar ratio of ytterbium salt to water in complexes was found to be 1:3 in any preparation and there was the same molar content of organic molecule in complexes, i. e. 0.65 for all three solvents after the complexes were maintained till constant in weight indiscator with concentrated H2SO4.
1989, 6(2): 82-83
Abstract:
Cinnamic acid in high yield (82.4%) was synthesized by Perkin reaction of acetic anhydride and benzaldehyde catalyzed by anhydrous potassium fluoride. Optimum conditions are benzaldehyde: acetic anhydride: KF=1: 3: 1.5(mol ratio), reaction temperature 160±1℃ and reaction time 100 min.
Cinnamic acid in high yield (82.4%) was synthesized by Perkin reaction of acetic anhydride and benzaldehyde catalyzed by anhydrous potassium fluoride. Optimum conditions are benzaldehyde: acetic anhydride: KF=1: 3: 1.5(mol ratio), reaction temperature 160±1℃ and reaction time 100 min.
1989, 6(2): 84-85
Abstract:
A simultaneous separation experiment for Gd-Tb-Dy with ammoniated HEH(EHP) was carried out. The scheme of separation is described and the products separated from three exists had the following purities: La-Gd 99.99%, Tb 68.9%, Dy-Lu 99.8%.
A simultaneous separation experiment for Gd-Tb-Dy with ammoniated HEH(EHP) was carried out. The scheme of separation is described and the products separated from three exists had the following purities: La-Gd 99.99%, Tb 68.9%, Dy-Lu 99.8%.
1989, 6(2): 86-88
Abstract:
Six new azo dyes were synthesized which are capable of dyeing polyester and cotton fiber blends. Maleic monoamide substituent in the dyes makes the latter soluble in water.The dyed PET/cotton blends showed a certain grade of fastness.
Six new azo dyes were synthesized which are capable of dyeing polyester and cotton fiber blends. Maleic monoamide substituent in the dyes makes the latter soluble in water.The dyed PET/cotton blends showed a certain grade of fastness.
1989, 6(2): 89-91
Abstract:
Two water soluble benzophenone sensitizexs are examined through measurements of UV,phosphorescence spectra, quantum yields,liftime of phosphorescence and transient absorption of flash photolysis. It has been found that the OH group in the side chain of sensitizer has a great influence on the photoinitiation activity. A possible interpretation is suggested.
Two water soluble benzophenone sensitizexs are examined through measurements of UV,phosphorescence spectra, quantum yields,liftime of phosphorescence and transient absorption of flash photolysis. It has been found that the OH group in the side chain of sensitizer has a great influence on the photoinitiation activity. A possible interpretation is suggested.
1989, 6(2): 92-94
Abstract:
The reduction of [Ag(IO6)2]7- at an Au minigrid electrode was studied by using thin layer spectroelectrochemical method.The reaction was found to proceed in two steps,namely:Ag(Ⅲ)→Ag(Ⅰ) and Ag(Ⅰ)→Ag(0). From the measured formal redox potential E0' at various pH a linear equation was obtained: E0'=1.611-0.086pH (V vs SCE). The reduction of copper complex was studied in the same way.
The reduction of [Ag(IO6)2]7- at an Au minigrid electrode was studied by using thin layer spectroelectrochemical method.The reaction was found to proceed in two steps,namely:Ag(Ⅲ)→Ag(Ⅰ) and Ag(Ⅰ)→Ag(0). From the measured formal redox potential E0' at various pH a linear equation was obtained: E0'=1.611-0.086pH (V vs SCE). The reduction of copper complex was studied in the same way.
1989, 6(2): 95-99
Abstract:
The adsorption effects in ion-exclusion chromatographic separation of formic, acetic,propionic, iso-butyric, butyric, iso-valeric and valeric acids have been studied. It is assumed that both Donnan membrane equilibrium and adsorption equilibrium are involved in chromatographic process. Thus, the following equation expressing the distribution coef-ficient, Kd, can be derived when water is used as an eluent: Kd=((K+1){[1+4(2+K)C/Ka]1/2-1})/(2K+3+[1+4(2+K)C/Ka]1/2) where K, K. and C are adsorption equilibrium constant, dissociation constant and acid concentration at peak maximum respectively.The adsorption equilibrium constants of some fatty acids are estimated from the retention data. Linear relationship between lnK and topological parameters, 1x are observed.
The adsorption effects in ion-exclusion chromatographic separation of formic, acetic,propionic, iso-butyric, butyric, iso-valeric and valeric acids have been studied. It is assumed that both Donnan membrane equilibrium and adsorption equilibrium are involved in chromatographic process. Thus, the following equation expressing the distribution coef-ficient, Kd, can be derived when water is used as an eluent: Kd=((K+1){[1+4(2+K)C/Ka]1/2-1})/(2K+3+[1+4(2+K)C/Ka]1/2) where K, K. and C are adsorption equilibrium constant, dissociation constant and acid concentration at peak maximum respectively.The adsorption equilibrium constants of some fatty acids are estimated from the retention data. Linear relationship between lnK and topological parameters, 1x are observed.
