Login In
2005 Volume 22 Issue 11
2005, 22(11): 1161-1166
Abstract:
With micro-porous silica functioned with 3-(trimethoxysilyl) propyl methacrylate reagent as carrier,a kind of novel molecularly imprinted polymer bound on silica surface was synthesized by using MAA and quinine as functional monomer and template respectively.The polymer was characterized by IR and SEM.MAA and quinine could interact to form super-molecular complexes,which were confirmed by fluorescence and UV spectroscopy.The adsorption properties of the polymers toward substrates were evaluated by equilibrium adsorptive experiments.The results show that there exist distinct difference between the template polymer and the control polymer,the maximum special adsorption amount toward template is 36.40 μmol/g.The separation factor reaches 1.64 for quinine and cinchonine.
With micro-porous silica functioned with 3-(trimethoxysilyl) propyl methacrylate reagent as carrier,a kind of novel molecularly imprinted polymer bound on silica surface was synthesized by using MAA and quinine as functional monomer and template respectively.The polymer was characterized by IR and SEM.MAA and quinine could interact to form super-molecular complexes,which were confirmed by fluorescence and UV spectroscopy.The adsorption properties of the polymers toward substrates were evaluated by equilibrium adsorptive experiments.The results show that there exist distinct difference between the template polymer and the control polymer,the maximum special adsorption amount toward template is 36.40 μmol/g.The separation factor reaches 1.64 for quinine and cinchonine.
2005, 22(11): 1167-1171
Abstract:
Thin-layer electrochemical studies of the underpotential deposition(UPD) of Bi and Te on cold rolled silver substrate have been performed.The voltammetric analysis of the underpotential shift demonstrated that the initial Te UPD on Bi-covered Ag and Bi UPD on Te-covered Ag fitted UPD dynamics mechanism.Thin film of bismuth telluride was formed by alternately depositing Te and Bi via an automated flow deposition system.X-ray diffraction indicated the deposits of Bi2Te3.EDX quantitative analysis gave a 2:3 stoichiometric ratio of Bi to Te,which was consistent with XRD result.Electron probe microanalysis of the deposits showed a network structure that resulted from the surface defects of the cold rolled Ag substrate and the lattice mismatch between substrate and deposit.
Thin-layer electrochemical studies of the underpotential deposition(UPD) of Bi and Te on cold rolled silver substrate have been performed.The voltammetric analysis of the underpotential shift demonstrated that the initial Te UPD on Bi-covered Ag and Bi UPD on Te-covered Ag fitted UPD dynamics mechanism.Thin film of bismuth telluride was formed by alternately depositing Te and Bi via an automated flow deposition system.X-ray diffraction indicated the deposits of Bi2Te3.EDX quantitative analysis gave a 2:3 stoichiometric ratio of Bi to Te,which was consistent with XRD result.Electron probe microanalysis of the deposits showed a network structure that resulted from the surface defects of the cold rolled Ag substrate and the lattice mismatch between substrate and deposit.
2005, 22(11): 1172-1177
Abstract:
The enzymatic interactions between lactate dehydrogenase and diethylenetriamine pentaacetic acid(DTPA) and its derivatives bisdimethylamide-diethylenetriamine pentaacetic acid(DTPA-BDMA) and bisisonicotinyl-diethylenetriamine pentaacetic acid(DTPA-BIN) have been investigated.DTPA and its derivatives react as competitive inhibitors and inhibit the activity of lactate dehydrogenase,the inhibition constants are 3.37,7.41,8.52 μmol/L,respectively.The results from Ultraviolet-Visible difference spectroscopy indicate that after binding with lactate dehydrogenase molecule,the carboxyl groups of DTPA are embedded in an inner hydrophobic environment.DTPA and its derivatives could reduce the tryptophan fluorescence emission intensity of dehydrogenase and exhibit little effects on the tyrosine fluorescence intensity.
The enzymatic interactions between lactate dehydrogenase and diethylenetriamine pentaacetic acid(DTPA) and its derivatives bisdimethylamide-diethylenetriamine pentaacetic acid(DTPA-BDMA) and bisisonicotinyl-diethylenetriamine pentaacetic acid(DTPA-BIN) have been investigated.DTPA and its derivatives react as competitive inhibitors and inhibit the activity of lactate dehydrogenase,the inhibition constants are 3.37,7.41,8.52 μmol/L,respectively.The results from Ultraviolet-Visible difference spectroscopy indicate that after binding with lactate dehydrogenase molecule,the carboxyl groups of DTPA are embedded in an inner hydrophobic environment.DTPA and its derivatives could reduce the tryptophan fluorescence emission intensity of dehydrogenase and exhibit little effects on the tyrosine fluorescence intensity.
2005, 22(11): 1178-1181
Abstract:
The Fe-doped,Co-doped and no-doped hexaaluminate catalysts were prepared by the reverse microemulsion method in the system of water/Triton X-100/n-butoanol/cyclohexane.The effects of doping elements on phase,specific surface area and activity for methane combustion were investigated by means of XRD,BET,H2-TPR.The XRD and TPR results indicate that a single phase LaFeAl11O19 hexaaluminate was formed according to the XRD spectrum of Fe-doped hexaaluminate catalyst,but XRD spectrum analyses of Co-doped and no-doped catalysts indicated that hexaaluminate was dominated phase and accompanied with a few perovskite phase when calcined at 1 400℃ for 3 h.H2-TPR patterns of the Fe-doped and Co-doped catalysts show that the reduction peaks appear in the range of 400℃ and 800℃,while no reduction peaks appear for no-doped catalyst.Reverse microemulsion method is beneficial to maintaining high surface area.The specific surface areas of prepared catalysts are about 11.6~16.3 m2/g.Compared with no-doped catalyst,the high-temperature activity of Fe-doped and Co-doped catalysts increased obviously,which made methane conversion 50% below 700℃ and methane complete conversion temperature was 800℃.However,the high-temperature activity of Fe-doped catalyst is better than that of Co-doped catalyst within 700℃,and their high-temperature activities are almost the same over 700℃.Fe-doped catalyst formed a single phase of hexaaluminate LaFeAl11O19 and had a higher activity for methane combustion.It might be a candidate for catalytic gas turbine combustor.
The Fe-doped,Co-doped and no-doped hexaaluminate catalysts were prepared by the reverse microemulsion method in the system of water/Triton X-100/n-butoanol/cyclohexane.The effects of doping elements on phase,specific surface area and activity for methane combustion were investigated by means of XRD,BET,H2-TPR.The XRD and TPR results indicate that a single phase LaFeAl11O19 hexaaluminate was formed according to the XRD spectrum of Fe-doped hexaaluminate catalyst,but XRD spectrum analyses of Co-doped and no-doped catalysts indicated that hexaaluminate was dominated phase and accompanied with a few perovskite phase when calcined at 1 400℃ for 3 h.H2-TPR patterns of the Fe-doped and Co-doped catalysts show that the reduction peaks appear in the range of 400℃ and 800℃,while no reduction peaks appear for no-doped catalyst.Reverse microemulsion method is beneficial to maintaining high surface area.The specific surface areas of prepared catalysts are about 11.6~16.3 m2/g.Compared with no-doped catalyst,the high-temperature activity of Fe-doped and Co-doped catalysts increased obviously,which made methane conversion 50% below 700℃ and methane complete conversion temperature was 800℃.However,the high-temperature activity of Fe-doped catalyst is better than that of Co-doped catalyst within 700℃,and their high-temperature activities are almost the same over 700℃.Fe-doped catalyst formed a single phase of hexaaluminate LaFeAl11O19 and had a higher activity for methane combustion.It might be a candidate for catalytic gas turbine combustor.
2005, 22(11): 1182-1186
Abstract:
By the oxidation of primary hydroxyl group of 1,2:3,4-di-O-isopropylidene-α-D-galactopyranose(1),1,2:3,4-di-O-isopropylidene-α-D-galacto-hexodialdo-1,5-pyranose(2) was prepared.By reaction of compound 2 with hydrazines or hydrazides,a series of 1,2:3,4-di-O-isopropylidene-α-D-galacto-(hexodialdo-)1,5-pyranose(heterocyclyl or aryl) substituted carbonyl hydrazone(3a~3f) and 1,2:3,4-di-O-isopropylidene-α-D-galacto-hexodialdo-1,5-pyranose substituted aryl hydrazone(4a,4b) were prepared.By nucleophilic addition reaction of compound 1 with glycosyl isothiocyanates,a series of new compounds 6-O-[N-(2,3,4,6-tetra-O-acetyl-glycosyl) thiocarbamoyl]-1,2:3,4-di-O-isopropylidene-α-D-galactopyranose(5a~5e) were prepared.The structures of all the compounds were established by IR,1H NMR and elemental analysis.
By the oxidation of primary hydroxyl group of 1,2:3,4-di-O-isopropylidene-α-D-galactopyranose(1),1,2:3,4-di-O-isopropylidene-α-D-galacto-hexodialdo-1,5-pyranose(2) was prepared.By reaction of compound 2 with hydrazines or hydrazides,a series of 1,2:3,4-di-O-isopropylidene-α-D-galacto-(hexodialdo-)1,5-pyranose(heterocyclyl or aryl) substituted carbonyl hydrazone(3a~3f) and 1,2:3,4-di-O-isopropylidene-α-D-galacto-hexodialdo-1,5-pyranose substituted aryl hydrazone(4a,4b) were prepared.By nucleophilic addition reaction of compound 1 with glycosyl isothiocyanates,a series of new compounds 6-O-[N-(2,3,4,6-tetra-O-acetyl-glycosyl) thiocarbamoyl]-1,2:3,4-di-O-isopropylidene-α-D-galactopyranose(5a~5e) were prepared.The structures of all the compounds were established by IR,1H NMR and elemental analysis.
2005, 22(11): 1187-1191
Abstract:
The catalysts of rare earth(Ⅲ) perfluorooctanesulfonates(RE(OSO2C8F17)3,RE=Sc,Y,La~Lu) had been prepared and Friedel-Crafts acylation anisole with Ac2O on RE(OSO2C8F17)3 catalysts in fluorous biphasic systems were investigated.Perfluorohexane(C6F14),perfluoromethylcyclohexane(C7F14),perfluorotoluene(C7F8),perfluoro-octane(C8F18),perfluorooctyl bromide(C8F17Br) and perfluorodecalin(C10F18,cis and trans-mixture) can be used as fluorous solvents for this reaction.Effects of the ratio of fluorous phase/organic phase and different acylation agents on the reaction were studied.The results show that the reaction exhibits a high para-selectivity of the acylation;Y(OSO2C8F17)3 and C10F18 are the best catalyst and fluorous solvent respectively.The yield of Friedel-Crafts acylation of anisole with Ac2O was 56% by using Y(OSO2C8F17)3 as the catalyst and C10F18 as the fluorous solvent,and para-selectivity exceeded 99%.By simple phase-separation,the catalytic activity showed a small drop after the fluorous phase containing only the catalyst was re-utilized for five times.
The catalysts of rare earth(Ⅲ) perfluorooctanesulfonates(RE(OSO2C8F17)3,RE=Sc,Y,La~Lu) had been prepared and Friedel-Crafts acylation anisole with Ac2O on RE(OSO2C8F17)3 catalysts in fluorous biphasic systems were investigated.Perfluorohexane(C6F14),perfluoromethylcyclohexane(C7F14),perfluorotoluene(C7F8),perfluoro-octane(C8F18),perfluorooctyl bromide(C8F17Br) and perfluorodecalin(C10F18,cis and trans-mixture) can be used as fluorous solvents for this reaction.Effects of the ratio of fluorous phase/organic phase and different acylation agents on the reaction were studied.The results show that the reaction exhibits a high para-selectivity of the acylation;Y(OSO2C8F17)3 and C10F18 are the best catalyst and fluorous solvent respectively.The yield of Friedel-Crafts acylation of anisole with Ac2O was 56% by using Y(OSO2C8F17)3 as the catalyst and C10F18 as the fluorous solvent,and para-selectivity exceeded 99%.By simple phase-separation,the catalytic activity showed a small drop after the fluorous phase containing only the catalyst was re-utilized for five times.
2005, 22(11): 1192-1196
Abstract:
A novel immunosensor for the determination of alpha fetoprotein(AFP) based on sol-gel technique was constructed by dispersing graphite and alpha fetoprotein in tetraethylorthosilicate(TEOS) derived sol-gel.With the increase of specific immuno-reaction complex of antibody and antigen,the membrane potential of the immunosensor changes.The membrane potential value is correlative with the antigen concentration in solution.According to this relationship,AFP can be detected quantificationally,the linearity range for determining AFP is 5.0×10-9~5.0×10-8g/mL with a correlation coefficient of 0.999 4.Other antigens such as carcino emtynic antigen(CEA),ferritin and hepatitis B surface antigen(HBsAg) do not interfere with the determination.The dependences of the potential response on immobilization method,incubation time,sensitivity and reproducibility were studied.The immunosensor was found to be stable for about 30 days when it was stored in dry state at 4℃.A satisfactory determination of AFP in serum samples can be obtained by this immunosensor.
A novel immunosensor for the determination of alpha fetoprotein(AFP) based on sol-gel technique was constructed by dispersing graphite and alpha fetoprotein in tetraethylorthosilicate(TEOS) derived sol-gel.With the increase of specific immuno-reaction complex of antibody and antigen,the membrane potential of the immunosensor changes.The membrane potential value is correlative with the antigen concentration in solution.According to this relationship,AFP can be detected quantificationally,the linearity range for determining AFP is 5.0×10-9~5.0×10-8g/mL with a correlation coefficient of 0.999 4.Other antigens such as carcino emtynic antigen(CEA),ferritin and hepatitis B surface antigen(HBsAg) do not interfere with the determination.The dependences of the potential response on immobilization method,incubation time,sensitivity and reproducibility were studied.The immunosensor was found to be stable for about 30 days when it was stored in dry state at 4℃.A satisfactory determination of AFP in serum samples can be obtained by this immunosensor.
2005, 22(11): 1197-1202
Abstract:
The study on the relation between the structure parameters of 142 carbon atoms in 39 amine compounds and their 13C NMR chemical shifts indicates that the 13C NMR chemical shifts of amine compounds are related to the ionicity index(INI),the polarizability effect index(PEI) of alkyl group and stereoscopic effect(α-c,β-c,γ-c):δc=175.22+1.70(∑PEI)-16.07(INI)-5.47α+4.01β-3.62γ.The above equation not only clarifis the relation between 13C NMR chemical shifts of aliphatic amines and its molecular structural information,but also provides a new calculation method for 13C NMR chemical shifts of aliphatic amines.It is the theorietcal basis for analyzing and predicting the 13C NMR chemical shifts of aliphatic amines.
The study on the relation between the structure parameters of 142 carbon atoms in 39 amine compounds and their 13C NMR chemical shifts indicates that the 13C NMR chemical shifts of amine compounds are related to the ionicity index(INI),the polarizability effect index(PEI) of alkyl group and stereoscopic effect(α-c,β-c,γ-c):δc=175.22+1.70(∑PEI)-16.07(INI)-5.47α+4.01β-3.62γ.The above equation not only clarifis the relation between 13C NMR chemical shifts of aliphatic amines and its molecular structural information,but also provides a new calculation method for 13C NMR chemical shifts of aliphatic amines.It is the theorietcal basis for analyzing and predicting the 13C NMR chemical shifts of aliphatic amines.
2005, 22(11): 1203-1207
Abstract:
Phase separation and mechanism of a hydrophilic organic phase-salt aqueous solution system were studied.A new method for measuring ΔV was established,and a new criterion to judge the phase separation ability was proposed,which is called as relative density criterion.According to the criterion,the less the relative density of upper phase vs pure organic solvent,the greater the phase separation ability.Factors affecting phase separation ability such as the kind and the concentration of organic solvent and salt and pH of the salt aqueous solution were investigated in detail.It was found that the phase separation process of the hydrophilic organic phase-salt aqueous solution system is a competition of organic solvent with salt for water molecules,and the phase separation ability is directly depended on the hydration ability of organic solvent and the salting out ability of salt,the greater the hydration ability of organic solvent,the poorer the phase separation ability,and the greater the salting out ability of salt,the stronger the phase separation ability,and the pH value of the aqueous solution has influence on phase separation ability.
Phase separation and mechanism of a hydrophilic organic phase-salt aqueous solution system were studied.A new method for measuring ΔV was established,and a new criterion to judge the phase separation ability was proposed,which is called as relative density criterion.According to the criterion,the less the relative density of upper phase vs pure organic solvent,the greater the phase separation ability.Factors affecting phase separation ability such as the kind and the concentration of organic solvent and salt and pH of the salt aqueous solution were investigated in detail.It was found that the phase separation process of the hydrophilic organic phase-salt aqueous solution system is a competition of organic solvent with salt for water molecules,and the phase separation ability is directly depended on the hydration ability of organic solvent and the salting out ability of salt,the greater the hydration ability of organic solvent,the poorer the phase separation ability,and the greater the salting out ability of salt,the stronger the phase separation ability,and the pH value of the aqueous solution has influence on phase separation ability.
2005, 22(11): 1208-1213
Abstract:
10-Hydroxy-5,10-dihydrophenophosphazine 10-oxide reacted with acetyl nitryl, viz.,a mixture of acetic acid and concentrated nitric acid to give 10-hydroxy-2-nitro-5,10-dihydrophenophosphazine 10-oxide(74%) which can be further hydrogenated to 2-amino-10-hydroxy-5,10-dihydrophenophosphazine 10-oxide(70%) at pH=7 over 5%Pd/C.The resulting nonmutagenic amino compound(via Salmonella/mammalian microsome assay) was employed as diazo moiety to couple with 3 intermediates containing pyrazolone nucleus to give three different azo dyes.From the investigations of the visible spectra and colorization performances of these azo dyes,it was found that they had deep coloring effects on dyeing wool or silk.In addition,the structures of two intermediates and three azo dyes prepared in this study were determined with spectroscopic techniques.
10-Hydroxy-5,10-dihydrophenophosphazine 10-oxide reacted with acetyl nitryl, viz.,a mixture of acetic acid and concentrated nitric acid to give 10-hydroxy-2-nitro-5,10-dihydrophenophosphazine 10-oxide(74%) which can be further hydrogenated to 2-amino-10-hydroxy-5,10-dihydrophenophosphazine 10-oxide(70%) at pH=7 over 5%Pd/C.The resulting nonmutagenic amino compound(via Salmonella/mammalian microsome assay) was employed as diazo moiety to couple with 3 intermediates containing pyrazolone nucleus to give three different azo dyes.From the investigations of the visible spectra and colorization performances of these azo dyes,it was found that they had deep coloring effects on dyeing wool or silk.In addition,the structures of two intermediates and three azo dyes prepared in this study were determined with spectroscopic techniques.
2005, 22(11): 1214-1219
Abstract:
A novel method was developed to prepare porous chitosan membranes with dibutyl phthalate as the porogen.The structure and performances of the porous chitosan membranes were examined by means of SEM,FTIR and BET method.The isothermal sorption kinetics of porous chitosan membranes for free chloride in water was investigated.The porous chitosan membranes prepared with dibutyl phthalate as porogen possess bigger porosity and specific surface area.The biggest water adsorption,porosity and specific surface area are respectively 196%,71.5% and 1.047 2 m2/g,and the biggest specific surface area is 5.52 times that of no-porous membrane.The porous chitosan membranes has a higher adsorption capacity for free chloride.The apparent sorption rate k are 0.232,0.194 and 0.136 min-1 respectively at 15℃,25℃,35℃.
A novel method was developed to prepare porous chitosan membranes with dibutyl phthalate as the porogen.The structure and performances of the porous chitosan membranes were examined by means of SEM,FTIR and BET method.The isothermal sorption kinetics of porous chitosan membranes for free chloride in water was investigated.The porous chitosan membranes prepared with dibutyl phthalate as porogen possess bigger porosity and specific surface area.The biggest water adsorption,porosity and specific surface area are respectively 196%,71.5% and 1.047 2 m2/g,and the biggest specific surface area is 5.52 times that of no-porous membrane.The porous chitosan membranes has a higher adsorption capacity for free chloride.The apparent sorption rate k are 0.232,0.194 and 0.136 min-1 respectively at 15℃,25℃,35℃.
2005, 22(11): 1220-1223
Abstract:
A novel phosphorus-containing naphthyl epoxy was prepared from the modification reaction of diethyl phosphite and DGEBN.The reaction was monitored with FTIR.The results show that the desirable reaction temperature is at 140℃.The proposed structure was confirmed by means of NMR spectra.The modified epoxies were cured with 4,4'-diaminodiphenylsulfone(DDS),and the thermal and mechanical properties of the thermosets were studied via TGA(TGA/FTIR) and DMTA.The glass transition temperature values are in the range of 150.5~159.2℃,and the storage modulus E' is above 1.5 GPa and the char yield higher than 27.6%.The organophosphorus modified epoxy thermosets have been found to degrade in two consecutive steps and are endowed with UL-94 vertical test of V-0 grade when the content of phosphorus is more than 2.02%.
A novel phosphorus-containing naphthyl epoxy was prepared from the modification reaction of diethyl phosphite and DGEBN.The reaction was monitored with FTIR.The results show that the desirable reaction temperature is at 140℃.The proposed structure was confirmed by means of NMR spectra.The modified epoxies were cured with 4,4'-diaminodiphenylsulfone(DDS),and the thermal and mechanical properties of the thermosets were studied via TGA(TGA/FTIR) and DMTA.The glass transition temperature values are in the range of 150.5~159.2℃,and the storage modulus E' is above 1.5 GPa and the char yield higher than 27.6%.The organophosphorus modified epoxy thermosets have been found to degrade in two consecutive steps and are endowed with UL-94 vertical test of V-0 grade when the content of phosphorus is more than 2.02%.
2005, 22(11): 1224-1229
Abstract:
Four sodium poly(phenyl glycidyl ether)-co-poly(butyl glycidyl ether) sulfonates(SPPBGE) were synthesized via the sulfonation of the polyether with sulfuric acid.The molecular structure of SPPBGE can be controlled by adjusting the constituent of polyether and sulfonation degree of its pendant phenyl.Dynamic surface tensions of SPPBGE water solutions were measured via the plate method,the result shows that the dynamic surface activity increases with increasing butyl glycidyl ether content in SPPBGE.Critic micell concentrations and minimum surface tensions were determined via surface tension measurement,they are in the ranges of 1 400~780 mg/L and 47.77~32.05 mN/m respectively,and they decrease with increasing butyl glycidyl ether content in SPPBGE.Micell morphologies of SPPBGE in water were observed with TEM,they change with the concentration and molecular structure.
Four sodium poly(phenyl glycidyl ether)-co-poly(butyl glycidyl ether) sulfonates(SPPBGE) were synthesized via the sulfonation of the polyether with sulfuric acid.The molecular structure of SPPBGE can be controlled by adjusting the constituent of polyether and sulfonation degree of its pendant phenyl.Dynamic surface tensions of SPPBGE water solutions were measured via the plate method,the result shows that the dynamic surface activity increases with increasing butyl glycidyl ether content in SPPBGE.Critic micell concentrations and minimum surface tensions were determined via surface tension measurement,they are in the ranges of 1 400~780 mg/L and 47.77~32.05 mN/m respectively,and they decrease with increasing butyl glycidyl ether content in SPPBGE.Micell morphologies of SPPBGE in water were observed with TEM,they change with the concentration and molecular structure.
2005, 22(11): 1230-1233
Abstract:
The phases,element contents,surface shapes,crystal sizes,specific surface and thermal behavior of the mineral Chinese traditional medicine,crude and calcined Ci Shi samples were determined by means of XRD,SEM,ICP and TG,respectively.The results indicate that after calcination,the main Fe3O4 phase Ci Shi was kept,but the Fe2O3 phase disappeared,the contents of harmful chemical elements Cd and Pb were obviously reduced,the crystal size became bigger(from 24.5 nmincreased to 35.7 nm) and the(surface)(became) more loose.TG curves of crude and calcined Ci Shi samples are different upon heating.The former shows two mass-loss steps(at 367.9422.1℃ and 568.8594.1℃),and the latter shows only one.These results might serve as a basis of quality evaluation of Ci Shi.
The phases,element contents,surface shapes,crystal sizes,specific surface and thermal behavior of the mineral Chinese traditional medicine,crude and calcined Ci Shi samples were determined by means of XRD,SEM,ICP and TG,respectively.The results indicate that after calcination,the main Fe3O4 phase Ci Shi was kept,but the Fe2O3 phase disappeared,the contents of harmful chemical elements Cd and Pb were obviously reduced,the crystal size became bigger(from 24.5 nmincreased to 35.7 nm) and the(surface)(became) more loose.TG curves of crude and calcined Ci Shi samples are different upon heating.The former shows two mass-loss steps(at 367.9422.1℃ and 568.8594.1℃),and the latter shows only one.These results might serve as a basis of quality evaluation of Ci Shi.
2005, 22(11): 1234-1238
Abstract:
The interactions between phen-5,6-dione and ethyldiamine or cis-diaminomaleonitrile were studied via high performance liquid chromatography and electrospray ionization mass spectrometry respectively.The results show that the intermediate from the addition reaction between the carbonyl and amine groups formed first,it was further dehydrated to form the double bond.And if a conjugated system could be formed,the resulting intermediate would be dehydrogenated further into conjugated compounds of condensed rings.
The interactions between phen-5,6-dione and ethyldiamine or cis-diaminomaleonitrile were studied via high performance liquid chromatography and electrospray ionization mass spectrometry respectively.The results show that the intermediate from the addition reaction between the carbonyl and amine groups formed first,it was further dehydrated to form the double bond.And if a conjugated system could be formed,the resulting intermediate would be dehydrogenated further into conjugated compounds of condensed rings.
2005, 22(11): 1239-1243
Abstract:
The electrocatalytic activity of single-wall carbon nanotube(SWNT) modified glassy carbon electrode(GCE) toward the oxidation of L-cysteine(L-Cys) was investigated.L-Cys produces an irreversible oxidation peak at 0.54 V(vs.SCE) in a phosphate buffer(PBS) of pH=7.0.The peak potential is much lower than that at a bare GCE.The peak current is proportional to the concentration of L-Cys in the range of 2.0×10-6~3.0×10-4 mol/L with a detection limit of 5.5×10-7 mol/L by means of cyclic voltammetry at the SWNT modified electrode.The relative standard deviation is 3.2% for solution containing 0.10 mmol/L(L-Cys)(n=7).The modified electrode has been satisfactorily used for the determination of amino acid injection samples in pharmaceutical formulations.The recoveries are in the range of 94%~97%.
The electrocatalytic activity of single-wall carbon nanotube(SWNT) modified glassy carbon electrode(GCE) toward the oxidation of L-cysteine(L-Cys) was investigated.L-Cys produces an irreversible oxidation peak at 0.54 V(vs.SCE) in a phosphate buffer(PBS) of pH=7.0.The peak potential is much lower than that at a bare GCE.The peak current is proportional to the concentration of L-Cys in the range of 2.0×10-6~3.0×10-4 mol/L with a detection limit of 5.5×10-7 mol/L by means of cyclic voltammetry at the SWNT modified electrode.The relative standard deviation is 3.2% for solution containing 0.10 mmol/L(L-Cys)(n=7).The modified electrode has been satisfactorily used for the determination of amino acid injection samples in pharmaceutical formulations.The recoveries are in the range of 94%~97%.
2005, 22(11): 1244-1248
Abstract:
A new complex-[η5-C5H4SiMe2N(SiMe3)2]2Yb(Ⅱ)·2THF was prepared via a convenient three-step synthesis.Its crystal structure was characterized by X-ray diffraction.It crystallizes in the mono-(clinic) system,space group P21/c,with a=1.646 87(12) nm,b=0.907 70(6) nm,c=3.049 4(3) nm,(β=)93.642(4)°,V=4.549 3(6) nm3,Z=2,C34H72N2O2Si6Yb,Mr=1 905.41,Dc=1.288 g/cm3,(F(000)=)1 840.00 and μ(MoKα)=22.42 cm-1(λ=0.071 070 nm).The final R and Rw are 0.039 and 0.050,respectively based on 7 814 observed reflections with I>3.00σ(1).The eight-coordinated ytterbium atom is bonded to two cyclopentadienyl rings and the oxygen atoms of the THF form a distorted tetrahedron.
A new complex-[η5-C5H4SiMe2N(SiMe3)2]2Yb(Ⅱ)·2THF was prepared via a convenient three-step synthesis.Its crystal structure was characterized by X-ray diffraction.It crystallizes in the mono-(clinic) system,space group P21/c,with a=1.646 87(12) nm,b=0.907 70(6) nm,c=3.049 4(3) nm,(β=)93.642(4)°,V=4.549 3(6) nm3,Z=2,C34H72N2O2Si6Yb,Mr=1 905.41,Dc=1.288 g/cm3,(F(000)=)1 840.00 and μ(MoKα)=22.42 cm-1(λ=0.071 070 nm).The final R and Rw are 0.039 and 0.050,respectively based on 7 814 observed reflections with I>3.00σ(1).The eight-coordinated ytterbium atom is bonded to two cyclopentadienyl rings and the oxygen atoms of the THF form a distorted tetrahedron.
2005, 22(11): 1249-1252
Abstract:
2-Ethoxy-1,4-naphthoquinone(EONQ) was synthesized by reflux in an ethanol solution with 2-hydroxy-1,4-naphthoquinone(HNQ) and ethanol as reactants and concentrated HNO3 as the catalyst.The(reflux) time,the dosage of catalyst and the reaction temperature were selected for optimizing reaction conditions.Product characterization was performed by means of UV-Vis,IR,1H NMR,elemental analysis,and GC-MS.The product was a farinose yellow solid.The experimental results indicate that the method is very simple in preparing EONQ.
2-Ethoxy-1,4-naphthoquinone(EONQ) was synthesized by reflux in an ethanol solution with 2-hydroxy-1,4-naphthoquinone(HNQ) and ethanol as reactants and concentrated HNO3 as the catalyst.The(reflux) time,the dosage of catalyst and the reaction temperature were selected for optimizing reaction conditions.Product characterization was performed by means of UV-Vis,IR,1H NMR,elemental analysis,and GC-MS.The product was a farinose yellow solid.The experimental results indicate that the method is very simple in preparing EONQ.
2005, 22(11): 1253-1257
Abstract:
The photocatalytic degradation of polyethylene glycol(PEG) with TiO2 nanoparticles as the photocatalyst was investigated.The fact that the amount of CO2 and the concentration of residue varied with reaction time indicates that it is a reaction of zero order and the degradation rate of PEG is negatively proportional to the average molecular weight of PEG.TGA and NMR results show that low molecular weight PEG,esters and other intermediates were produced during the degradation reaction.PEG was finally mineralized to CO2 and(H2O).
The photocatalytic degradation of polyethylene glycol(PEG) with TiO2 nanoparticles as the photocatalyst was investigated.The fact that the amount of CO2 and the concentration of residue varied with reaction time indicates that it is a reaction of zero order and the degradation rate of PEG is negatively proportional to the average molecular weight of PEG.TGA and NMR results show that low molecular weight PEG,esters and other intermediates were produced during the degradation reaction.PEG was finally mineralized to CO2 and(H2O).
2005, 22(11): 1258-1261
Abstract:
On the basis of the successful synthesis of N-(9-acridinyl)glycine,other 9 new fluorescent reagents N-(9-acridinyl)-α-aminoacids were synthesized under the optimized conditions.All the compounds were characterized by IR,1H NMR and element analysis.The preliminary data suggest that these amino-acid derivatives might be employed as fluorescent probes for bio-molecules or reagents for fluorimetric analysis of metal ions.
On the basis of the successful synthesis of N-(9-acridinyl)glycine,other 9 new fluorescent reagents N-(9-acridinyl)-α-aminoacids were synthesized under the optimized conditions.All the compounds were characterized by IR,1H NMR and element analysis.The preliminary data suggest that these amino-acid derivatives might be employed as fluorescent probes for bio-molecules or reagents for fluorimetric analysis of metal ions.
2005, 22(11): 1262-1264
Abstract:
Nanoscale platinum wires have been prepared by means of an electrochemical technique on DNA template.The platinum nanowires were characterized via transmission electron microscopy(TEM) and X-ray diffraction(XRD).The length of the nanowires was about 50 nm and the diameter was about 1.3 μm.It was found that the concentration of PtCl4,activation time,electrolytic potential and reducing time affected the sizes and shapes of the platinum nanowires.
Nanoscale platinum wires have been prepared by means of an electrochemical technique on DNA template.The platinum nanowires were characterized via transmission electron microscopy(TEM) and X-ray diffraction(XRD).The length of the nanowires was about 50 nm and the diameter was about 1.3 μm.It was found that the concentration of PtCl4,activation time,electrolytic potential and reducing time affected the sizes and shapes of the platinum nanowires.
2005, 22(11): 1265-1267
Abstract:
Extraction and determination method of solanesol in waste tobacco leaves by combination of ultrasonic extraction and high performance liquid chromatography(HPLC) was demonstrated.Ultrasonic extraction showed advantage over the other methods.Thereby the conditions of ultrasonic extraction were(optimized).The results show that extraction yield is the highest under 80 kHz for 20 min with 80% ethanol at a ratio of V(liquid)/m(solid)=10 mL/g.
Extraction and determination method of solanesol in waste tobacco leaves by combination of ultrasonic extraction and high performance liquid chromatography(HPLC) was demonstrated.Ultrasonic extraction showed advantage over the other methods.Thereby the conditions of ultrasonic extraction were(optimized).The results show that extraction yield is the highest under 80 kHz for 20 min with 80% ethanol at a ratio of V(liquid)/m(solid)=10 mL/g.
2005, 22(11): 1268-1270
Abstract:
A hexanuclear copper(Ⅰ) cluster[Cu6(C5H4NS)6] was synthesized by means of the hydrothermal reaction of[Cu(PPh3)2(MeCN)2]ClO4 with(2-mercaptopyridine-1-oxide) in the presence of 2-butanol,Et3N and water and characterized by elemental analysis,IR,TGA and solid state fluorescence spectroscopy as well as X-ray diffractometry.The crystallographic data for the title complex,C15H12Cu3N3S3,are Mr=521.08,monoclinic space group P2(1)/n and the cell parameters are:a=0.958 59(6) nm,b=(1.604 85(12) nm),(c=)0.122 712(10) nm,β=108.863(2)°,V=1.786 4(2) nm3,Z=4,Dc=(1.937 Mg/m3),R1=0.030 1,ωR2=0.031 5(I>2σ(I)),F(000)=1 032,μ=3.890 mm-1,R(int)=0.050 1,S=0.598.The title complex exhibits highly thermal stability and strong low energy fluorescence((λ=744 nm) when it is irradiated by the light(λ=468 nm) in solid state at room temperature.
A hexanuclear copper(Ⅰ) cluster[Cu6(C5H4NS)6] was synthesized by means of the hydrothermal reaction of[Cu(PPh3)2(MeCN)2]ClO4 with(2-mercaptopyridine-1-oxide) in the presence of 2-butanol,Et3N and water and characterized by elemental analysis,IR,TGA and solid state fluorescence spectroscopy as well as X-ray diffractometry.The crystallographic data for the title complex,C15H12Cu3N3S3,are Mr=521.08,monoclinic space group P2(1)/n and the cell parameters are:a=0.958 59(6) nm,b=(1.604 85(12) nm),(c=)0.122 712(10) nm,β=108.863(2)°,V=1.786 4(2) nm3,Z=4,Dc=(1.937 Mg/m3),R1=0.030 1,ωR2=0.031 5(I>2σ(I)),F(000)=1 032,μ=3.890 mm-1,R(int)=0.050 1,S=0.598.The title complex exhibits highly thermal stability and strong low energy fluorescence((λ=744 nm) when it is irradiated by the light(λ=468 nm) in solid state at room temperature.
2005, 22(11): 1271-1273
Abstract:
Diphenyl carbonate(DPC) as an important product was used for synthesizing polycarbonate instead of phosgene.To detect the reaction process and products,a gas chromatographic method for analyzing the related six compounds(methanol,DMC,anisole,MPC,phenol,DPC) during the transesterification of phenol with dimethyl carbonate(DMC) was first proposed and described.All the compounds mentioned above were well separated through a FFAP chromatographic capillary column.A good linear relationship between the injection amount versus peak area was observed with the correlation coefficients of 0.996 3,0.994 6,(0.996 9),0.998 1,0.977,0.996 1,and the detection limits of six related compounds were founded to be 0.114,0.171,0.041 0,0.080 4,0.051 9,0.075 8 g/L respectively.
Diphenyl carbonate(DPC) as an important product was used for synthesizing polycarbonate instead of phosgene.To detect the reaction process and products,a gas chromatographic method for analyzing the related six compounds(methanol,DMC,anisole,MPC,phenol,DPC) during the transesterification of phenol with dimethyl carbonate(DMC) was first proposed and described.All the compounds mentioned above were well separated through a FFAP chromatographic capillary column.A good linear relationship between the injection amount versus peak area was observed with the correlation coefficients of 0.996 3,0.994 6,(0.996 9),0.998 1,0.977,0.996 1,and the detection limits of six related compounds were founded to be 0.114,0.171,0.041 0,0.080 4,0.051 9,0.075 8 g/L respectively.
2005, 22(11): 1274-1276
Abstract:
In basic NH3-NH4Cl buffer solutions,the molecules of complex of some metal(Ⅱ) ions with dithizone can associate one another to produce stable micro-particles,which exhibit resonance photo scattering effect and different color.There is a strongest resonance scattering peak at 605 nm for Zn(Ⅱ),at 540 nm for Pb(Ⅱ),at 600 nm for Co(Ⅱ),at 560 nm for Ni(Ⅱ),at 560 nm for Cd(Ⅱ), at 570 nm for Cu(Ⅱ) and at 560 nm for Hg(Ⅱ) in their corresponding particle systems.There is Alinear relationship between the scattering intensity and metal ion concentration.Among them,the system of Zn(Ⅱ)-dithizone is most sensitive and is therefore chosen for the determination of Zn concentration in the range of 2.0×10-8~1.54×10-6 g/mL),with a detection limit of 8.0×10-9 g/mL.This method has been applied to the determination of microelement Zn in samples with satisfactory sensitivity,simplicity and reproducibility.
In basic NH3-NH4Cl buffer solutions,the molecules of complex of some metal(Ⅱ) ions with dithizone can associate one another to produce stable micro-particles,which exhibit resonance photo scattering effect and different color.There is a strongest resonance scattering peak at 605 nm for Zn(Ⅱ),at 540 nm for Pb(Ⅱ),at 600 nm for Co(Ⅱ),at 560 nm for Ni(Ⅱ),at 560 nm for Cd(Ⅱ), at 570 nm for Cu(Ⅱ) and at 560 nm for Hg(Ⅱ) in their corresponding particle systems.There is Alinear relationship between the scattering intensity and metal ion concentration.Among them,the system of Zn(Ⅱ)-dithizone is most sensitive and is therefore chosen for the determination of Zn concentration in the range of 2.0×10-8~1.54×10-6 g/mL),with a detection limit of 8.0×10-9 g/mL.This method has been applied to the determination of microelement Zn in samples with satisfactory sensitivity,simplicity and reproducibility.
