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2012 Volume 29 Issue 6
2012, 29(6): 611-616
doi: 10.3724/SP.J.1095.2012.00277
Abstract:
We mainly introduced the non-enzymatic glucose sensor measurements in this paper.Compared to the enzymatic measurements,the non-enzymatic measurements overcome the disadvantages that the enzymes are easily denatured during the immobilization procedures due to the intrinsic nature of enzymes.In addition,the non-enzymatic measurements show an acceptable reproducibility,a good stability and high interferences.
We mainly introduced the non-enzymatic glucose sensor measurements in this paper.Compared to the enzymatic measurements,the non-enzymatic measurements overcome the disadvantages that the enzymes are easily denatured during the immobilization procedures due to the intrinsic nature of enzymes.In addition,the non-enzymatic measurements show an acceptable reproducibility,a good stability and high interferences.
2012, 29(6): 617-622
doi: 10.3724/SP.J.1095.2012.00313
Abstract:
Diarylacetylene monomers(1a~1d) containing substituted biphenyl and Si groups were synthesized and then polymerized with TaCl5-n-Bu4Sn catalyst to generate the corresponding polymers(2a,2b,and 2d).The produced polymers showed good solubility in common organic solvents.Polymers 2a and 2b afforded free standing membranes by casting from their toluene solution.Desilylation of membranes 2a and 2b was carried out with trifluoroacetic acid to give membranes 3a and 3b,which were insoluble in any organic solvents.According to thermogravimetric analysis,both the trimethylsilyl-containing and the desilylated polymers exhibited high thermal stability,the onset temperatures of mass loss in air were 340℃ and 430℃,respectively.The oxygen permeability coefficients(PO2) of polymers 2a and 2b were 99 and 160 barrers,respectively.Upon desilylation,the PO2 of 3a and 3b decreased to 22 and 65 barrers,respectively.The separation factors of oxygen against nitrogen(PO2/PN2) of the present polymer membranes ranged from 2.4~3.3,and they tend to decrease as the PO2 increased.By determining the gas diffusion coefficient(D) and gas solubility coefficient(S),the result indicates that the decrease of gas permeability upon desilylation was mainly derived from the decrease of D value.
Diarylacetylene monomers(1a~1d) containing substituted biphenyl and Si groups were synthesized and then polymerized with TaCl5-n-Bu4Sn catalyst to generate the corresponding polymers(2a,2b,and 2d).The produced polymers showed good solubility in common organic solvents.Polymers 2a and 2b afforded free standing membranes by casting from their toluene solution.Desilylation of membranes 2a and 2b was carried out with trifluoroacetic acid to give membranes 3a and 3b,which were insoluble in any organic solvents.According to thermogravimetric analysis,both the trimethylsilyl-containing and the desilylated polymers exhibited high thermal stability,the onset temperatures of mass loss in air were 340℃ and 430℃,respectively.The oxygen permeability coefficients(PO2) of polymers 2a and 2b were 99 and 160 barrers,respectively.Upon desilylation,the PO2 of 3a and 3b decreased to 22 and 65 barrers,respectively.The separation factors of oxygen against nitrogen(PO2/PN2) of the present polymer membranes ranged from 2.4~3.3,and they tend to decrease as the PO2 increased.By determining the gas diffusion coefficient(D) and gas solubility coefficient(S),the result indicates that the decrease of gas permeability upon desilylation was mainly derived from the decrease of D value.
2012, 29(6): 623-627
doi: 10.3724/SP.J.1095.2012.00325
Abstract:
A series of waterborne polyurethane(WPU) dispersions with different molar ratio of -NCO to -OH(n(-NCO)/n(-OH)) were synthesized using tetramethyl xylene diisocyanate(TMXDI),polyester diol and dimethylolpropionic acid as raw materials.The effect of n(-NCO)/n(-OH) on the properties of WPU was investigated.The experiment results showed that with the increase of n(-NCO)/n(-OH),the particle size increased while the particle size distribution became wider;the crystallinity,thermostability and the water resistance tend to decrease as well.When n(-NCO)/n(-OH) was 3.0,the particle size of WPU based TXMDI was fallen in the range of 10 to 30 nm,the decomposition temperature and 24 h water absorption of WPU film were 275℃ and below 10%,respectively.
A series of waterborne polyurethane(WPU) dispersions with different molar ratio of -NCO to -OH(n(-NCO)/n(-OH)) were synthesized using tetramethyl xylene diisocyanate(TMXDI),polyester diol and dimethylolpropionic acid as raw materials.The effect of n(-NCO)/n(-OH) on the properties of WPU was investigated.The experiment results showed that with the increase of n(-NCO)/n(-OH),the particle size increased while the particle size distribution became wider;the crystallinity,thermostability and the water resistance tend to decrease as well.When n(-NCO)/n(-OH) was 3.0,the particle size of WPU based TXMDI was fallen in the range of 10 to 30 nm,the decomposition temperature and 24 h water absorption of WPU film were 275℃ and below 10%,respectively.
2012, 29(6): 628-632
doi: 10.3724/SP.J.1095.2012.00330
Abstract:
Cationic polyacrylamide P(AM/MAPD) was prepared by the radical copolymerization of acrylamide(AM) and 1-methacryloyloxypropyl-3-decylimidazolium chloride(MAPD-Cl).The as-synthesized product was characterized by IR and proved to be the target product.Synthetic conditions were optimized with the single factor optimization coupled with the response surface methodology(RSM).Based on the results of single factor optimization,mass fraction of monomer,reaction temperature,initiator concentration,and time were obtained and compared with those using RSM method.A mathematic model of the intrinsic viscosity of the polymer was established,and the optimized conditions are as follows: 25.41% of mass fraction of monomer,0.03% of mass fraction of initiator(NaHSO3-(NH4)2S2O4),26.43℃ reaction temperature,10 h reaction time.In addition,the intrinsic viscosity for polymer is 12.56 dL/g.
Cationic polyacrylamide P(AM/MAPD) was prepared by the radical copolymerization of acrylamide(AM) and 1-methacryloyloxypropyl-3-decylimidazolium chloride(MAPD-Cl).The as-synthesized product was characterized by IR and proved to be the target product.Synthetic conditions were optimized with the single factor optimization coupled with the response surface methodology(RSM).Based on the results of single factor optimization,mass fraction of monomer,reaction temperature,initiator concentration,and time were obtained and compared with those using RSM method.A mathematic model of the intrinsic viscosity of the polymer was established,and the optimized conditions are as follows: 25.41% of mass fraction of monomer,0.03% of mass fraction of initiator(NaHSO3-(NH4)2S2O4),26.43℃ reaction temperature,10 h reaction time.In addition,the intrinsic viscosity for polymer is 12.56 dL/g.
2012, 29(6): 633-638
doi: 10.3724/SP.J.1095.2012.00383
Abstract:
A new polymerizable fluorescent dye with high fluorescence quantum yield(0.69) was synthesized.The dye possesses even better photo stability than commercial dye Rhodamine B.The fluorescent ultrafine polymer nanoparticles were obtained by emulsion polymerization initialized by redox initiator.The average diameter of the nanoparticles prepared by Triton X-100 as emulsifier and methyl methacrylate(MMA) as assistant emulsifier and monomer is 22 nm,while the diameter is about 150 nm without MMA.The benzyl chloride groups provide an easy way to further function.
A new polymerizable fluorescent dye with high fluorescence quantum yield(0.69) was synthesized.The dye possesses even better photo stability than commercial dye Rhodamine B.The fluorescent ultrafine polymer nanoparticles were obtained by emulsion polymerization initialized by redox initiator.The average diameter of the nanoparticles prepared by Triton X-100 as emulsifier and methyl methacrylate(MMA) as assistant emulsifier and monomer is 22 nm,while the diameter is about 150 nm without MMA.The benzyl chloride groups provide an easy way to further function.
2012, 29(6): 639-642
doi: 10.3724/SP.J.1095.2012.00329
Abstract:
Sub-micrometer monodispersed polystyrene microspheres were synthesized by the emulsion polymerization technique.The three-dimensional ordered polystyrene colloidal crystals were fabricated on the surface of emulsion through a solvent evaporation method.We have fabricated colloidal crystals with the thickness of more than 450 μm by using this method.It was found that the key factor of preparation of colloidal crystal was the evaporation rate.The capillary force was the main driving force for the regular assembling of the colloidal crystal.With the decrease of solvent,the floating capability of microspheres decreased due to the increase of viscosity and caused the increase of defects.
Sub-micrometer monodispersed polystyrene microspheres were synthesized by the emulsion polymerization technique.The three-dimensional ordered polystyrene colloidal crystals were fabricated on the surface of emulsion through a solvent evaporation method.We have fabricated colloidal crystals with the thickness of more than 450 μm by using this method.It was found that the key factor of preparation of colloidal crystal was the evaporation rate.The capillary force was the main driving force for the regular assembling of the colloidal crystal.With the decrease of solvent,the floating capability of microspheres decreased due to the increase of viscosity and caused the increase of defects.
2012, 29(6): 643-648
doi: 10.3724/SP.J.1095.2012.00271
Abstract:
α(β)-tetra-phenoxy phthalocyaninato zinc complexes have been synthesized via a two-step process using 3(4)-nitrobenzene-1,2-dicarbonitrile and phenol as precursors.The products were characterized by means of IR spectrum,UV-Vis spectrum,1H NMR spectrum,mass spectrum and elemental analysis.The UV-Vis spectra,photoluminescence spectra of spin-coated film and pressed solid pellet were compared.The fluorescences of both compressed and spin-coated samples had red-shifts larger than 161 nm compared to that obtained from solution.In addition,their fluorescence peaks are broader than that in solution.The fluorescence of β-substituted phthalocyanines has a greater red-shift than that of α-substituted phthalocyanines.The two kinds of fabricated devices showed similar electroluminescent spectra around 880 nm.
α(β)-tetra-phenoxy phthalocyaninato zinc complexes have been synthesized via a two-step process using 3(4)-nitrobenzene-1,2-dicarbonitrile and phenol as precursors.The products were characterized by means of IR spectrum,UV-Vis spectrum,1H NMR spectrum,mass spectrum and elemental analysis.The UV-Vis spectra,photoluminescence spectra of spin-coated film and pressed solid pellet were compared.The fluorescences of both compressed and spin-coated samples had red-shifts larger than 161 nm compared to that obtained from solution.In addition,their fluorescence peaks are broader than that in solution.The fluorescence of β-substituted phthalocyanines has a greater red-shift than that of α-substituted phthalocyanines.The two kinds of fabricated devices showed similar electroluminescent spectra around 880 nm.
2012, 29(6): 649-657
doi: 10.3724/SP.J.1095.2012.00403
Abstract:
SrFeO3-δ products with microcube-shaped tetragonal type,and nano lamellae-shaped brounmillerite and orthorhombic mixed type were successfully synthesized by a molten salt route through controlling temperature and time and lid-closure reaction.The synthesized products were systematically studied by X-ray powder diffraction,field-emission scanning electron microscopy,transmission electron microscopy,and energy dispersive X-ray spectroscopy as well as thermogravimetric analysis.The results show that the sample SrFeO2.86 has a tetrahedral symmetry with I4/mmm supercell.Evidence of weak superstructures,reflecting local oxygen ordering,is also obtained from electron diffraction.SrFeO2.62 was found to be a composite material by combination of a brownmillerite phase with Ibma space group and an orthorhombic structure with Cmmm space group.The results of magnetic properties indicate that the morphology of the SrFeO3-δ products has great effects on their properties.Reduced spin frustration is associated with an increasing ferromagnetic interaction.The shape anisotropy results in distinct difference of magnetic properties in different oxides with nearly the same composition.
SrFeO3-δ products with microcube-shaped tetragonal type,and nano lamellae-shaped brounmillerite and orthorhombic mixed type were successfully synthesized by a molten salt route through controlling temperature and time and lid-closure reaction.The synthesized products were systematically studied by X-ray powder diffraction,field-emission scanning electron microscopy,transmission electron microscopy,and energy dispersive X-ray spectroscopy as well as thermogravimetric analysis.The results show that the sample SrFeO2.86 has a tetrahedral symmetry with I4/mmm supercell.Evidence of weak superstructures,reflecting local oxygen ordering,is also obtained from electron diffraction.SrFeO2.62 was found to be a composite material by combination of a brownmillerite phase with Ibma space group and an orthorhombic structure with Cmmm space group.The results of magnetic properties indicate that the morphology of the SrFeO3-δ products has great effects on their properties.Reduced spin frustration is associated with an increasing ferromagnetic interaction.The shape anisotropy results in distinct difference of magnetic properties in different oxides with nearly the same composition.
2012, 29(6): 658-662
doi: 10.3724/SP.J.1095.2012.00304
Abstract:
Using porous anodic aluminium oxide(AAO) membrane as template,a precursor containing triblock copolymer EO20PO70EO20(P123) as porogen,Ce(NO3)3·6H2O as the cerium source and ethanol as the solvent was loaded into the AAO nano-channels by a pressure-induced technique under vacuum.After heat treatment at 600℃ for 180 min and removal of AAO by NaOH,one-dimensional CeO2 nanofibers with mesoporous structure were fabricated.The obtained samples were characterized by means of SEM,TEM,XRD,EDS and N2 sorption and desorption.The results show that the CeO2 nanofibers have mesopore structure and high surface area,and good photoluminescence property.
Using porous anodic aluminium oxide(AAO) membrane as template,a precursor containing triblock copolymer EO20PO70EO20(P123) as porogen,Ce(NO3)3·6H2O as the cerium source and ethanol as the solvent was loaded into the AAO nano-channels by a pressure-induced technique under vacuum.After heat treatment at 600℃ for 180 min and removal of AAO by NaOH,one-dimensional CeO2 nanofibers with mesoporous structure were fabricated.The obtained samples were characterized by means of SEM,TEM,XRD,EDS and N2 sorption and desorption.The results show that the CeO2 nanofibers have mesopore structure and high surface area,and good photoluminescence property.
2012, 29(6): 663-667
doi: 10.3724/SP.J.1095.2012.00324
Abstract:
In order to explore the mechanisms of killing cancer cells via nano-TiO2 photocatalytic oxidization,gastric cancer cell line BGC-823 was cultured as research object in this study.The morphologic changes were observed by inverted phase-contrast microscope,the apoptotic rates and cell cycle of BGC-823 cells were examined by flow cytometer.The results showed that nano-TiO2 photocatalytic oxidation caused the necrosis or secondary necrosis of BGC-823 cells,and inhibited the synthesis of DNA and their proliferation process,through arresting the G2/M phase and inducing apoptosis of BGC-823 cells.Significant arrest was observed and the apoptotic rates of BGC-823 cells reached 24.34% when the coated amount of TiO2 was 9.8×10-7 g/cm2 and the irradiation time was 40 min.
In order to explore the mechanisms of killing cancer cells via nano-TiO2 photocatalytic oxidization,gastric cancer cell line BGC-823 was cultured as research object in this study.The morphologic changes were observed by inverted phase-contrast microscope,the apoptotic rates and cell cycle of BGC-823 cells were examined by flow cytometer.The results showed that nano-TiO2 photocatalytic oxidation caused the necrosis or secondary necrosis of BGC-823 cells,and inhibited the synthesis of DNA and their proliferation process,through arresting the G2/M phase and inducing apoptosis of BGC-823 cells.Significant arrest was observed and the apoptotic rates of BGC-823 cells reached 24.34% when the coated amount of TiO2 was 9.8×10-7 g/cm2 and the irradiation time was 40 min.
2012, 29(6): 668-673
doi: 10.3724/SP.J.1095.2012.00413
Abstract:
Fe-pillared bentonite catalyst was prepared under microwave irradiation using calcium base bentonite as the precursor,and characterized by X-ray diffraction,N2 adsorption-desorption,scanning electron microscope,energy dispersive spectrometer,thermogravimetry differential scanning calorimetry.The results showed that the iron was pillared at the layer of bentonite well.The effects of preparation condition including reaction time,dosage of catalyst on the degradation of methyl orange were investigated.It was found that the degradation rate of the 100 mg/L methyl orange at pH=3.0 could reach 98.1% after 60 min reaction using 1.5 g/L Fe-pillared bentonite as the catalyst,which was prepared under 500 W microwave radiation keeping the reaction temperature at 80℃ for 10 min,and 7.345×10-3 mol/L H2O2 as oxidant.
Fe-pillared bentonite catalyst was prepared under microwave irradiation using calcium base bentonite as the precursor,and characterized by X-ray diffraction,N2 adsorption-desorption,scanning electron microscope,energy dispersive spectrometer,thermogravimetry differential scanning calorimetry.The results showed that the iron was pillared at the layer of bentonite well.The effects of preparation condition including reaction time,dosage of catalyst on the degradation of methyl orange were investigated.It was found that the degradation rate of the 100 mg/L methyl orange at pH=3.0 could reach 98.1% after 60 min reaction using 1.5 g/L Fe-pillared bentonite as the catalyst,which was prepared under 500 W microwave radiation keeping the reaction temperature at 80℃ for 10 min,and 7.345×10-3 mol/L H2O2 as oxidant.
2012, 29(6): 674-681
doi: 10.3724/SP.J.1095.2012.00430
Abstract:
Polypyrrole/graphite oxide composites(PPy/GO) with different mass ratios were first prepared by in situ polymerization and then reduced by NaBH4 to form polypyrrole/reduced graphene oxide(PPy/RGO).The morphology and structure of the composites were characterized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR) and field emission scanning electron microscopy(FESEM).The electrochemical performances of the composites were investigated by cyclic voltammetry,galvanostatic charge discharge and electrochemical impedance techniques.The experimental results showed that the composites with the mass ratio of Py to GO up to 95: 5 reached the specific capacitances of 401.5 and 314.5 F/g before and after reduction at the current density of 0.5 A/g,respectively,which were much higher in comparison with pristine GO(34.8 F/g) and PPy(267.5 F/g).The capacitance retention is about 62.5% for PPy/RGO after 1200 cycles,which is much better than those of 16.8% for PPy and 46.4% for PPy/GO,indicating that the PPy/RGO has a high cycle stability and potential as electrode material for supercapacitors.
Polypyrrole/graphite oxide composites(PPy/GO) with different mass ratios were first prepared by in situ polymerization and then reduced by NaBH4 to form polypyrrole/reduced graphene oxide(PPy/RGO).The morphology and structure of the composites were characterized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR) and field emission scanning electron microscopy(FESEM).The electrochemical performances of the composites were investigated by cyclic voltammetry,galvanostatic charge discharge and electrochemical impedance techniques.The experimental results showed that the composites with the mass ratio of Py to GO up to 95: 5 reached the specific capacitances of 401.5 and 314.5 F/g before and after reduction at the current density of 0.5 A/g,respectively,which were much higher in comparison with pristine GO(34.8 F/g) and PPy(267.5 F/g).The capacitance retention is about 62.5% for PPy/RGO after 1200 cycles,which is much better than those of 16.8% for PPy and 46.4% for PPy/GO,indicating that the PPy/RGO has a high cycle stability and potential as electrode material for supercapacitors.
2012, 29(6): 682-690
doi: 10.3724/SP.J.1095.2012.00288
Abstract:
Composites of multi-wall carbon nano-tubes(MWCNTs) non-covalently functionalized by polymers with different structures were prepared through co-mixing purified MWCNTs and different polymers.These composites were used to entrap laccase(lac) molecules.The enzyme loading amount of carriers,the specific activity and stability of entrapped laccase on these carriers were determined.After coating glassy carbon(GC) electrodes with these composites,the direct electrochemical behavior of these laccase-based electrodes and their catalytic activity toward oxygen reduction reaction in deaerated phosphate buffer solution were investigated with cyclic voltammetry.The velocity constants of electron transfer between entrapped laccase molecules and electrode were also estimated.Experimental results indicate that the electron transfer could be favored when the polymer contains laccase-phlic functional group or groups which can interact with cofactor of laccase and laccases entrapped in composites retaining original conformation as free laccase.Among these laccase-based electrodes,formal potential of direct electron transfer occurred in lac/NIPAM-co-BPCP-MWCNTs/GC(NIPAM-co-BPCP:N-isopropylacrylamide-co-N-allyl-1-benzoyl-3-phenyl-4,5-dihydro-4-formamidopyrazole)(605 mV) is not only relatively closer to formal potential characterized T1 active site in laccase(580 mV) but also displays faster hetero-phase electron transfer velocity(0.726 s-1),higher enzyme loading(103.5 mg/g),improved immobilized laccase specific activity(1.68 U/mg),higher catalytic activity for oxygen reduction reaction(onset potential of oxygen reduction:820 mV,catalytic peak current at 650 mV:85.5 μA),good reusability and favorable long-term durability.
Composites of multi-wall carbon nano-tubes(MWCNTs) non-covalently functionalized by polymers with different structures were prepared through co-mixing purified MWCNTs and different polymers.These composites were used to entrap laccase(lac) molecules.The enzyme loading amount of carriers,the specific activity and stability of entrapped laccase on these carriers were determined.After coating glassy carbon(GC) electrodes with these composites,the direct electrochemical behavior of these laccase-based electrodes and their catalytic activity toward oxygen reduction reaction in deaerated phosphate buffer solution were investigated with cyclic voltammetry.The velocity constants of electron transfer between entrapped laccase molecules and electrode were also estimated.Experimental results indicate that the electron transfer could be favored when the polymer contains laccase-phlic functional group or groups which can interact with cofactor of laccase and laccases entrapped in composites retaining original conformation as free laccase.Among these laccase-based electrodes,formal potential of direct electron transfer occurred in lac/NIPAM-co-BPCP-MWCNTs/GC(NIPAM-co-BPCP:N-isopropylacrylamide-co-N-allyl-1-benzoyl-3-phenyl-4,5-dihydro-4-formamidopyrazole)(605 mV) is not only relatively closer to formal potential characterized T1 active site in laccase(580 mV) but also displays faster hetero-phase electron transfer velocity(0.726 s-1),higher enzyme loading(103.5 mg/g),improved immobilized laccase specific activity(1.68 U/mg),higher catalytic activity for oxygen reduction reaction(onset potential of oxygen reduction:820 mV,catalytic peak current at 650 mV:85.5 μA),good reusability and favorable long-term durability.
2012, 29(6): 691-696
doi: 10.3724/SP.J.1095.2012.00317
Abstract:
β-PbO2,TiO2-doped β-PbO2,Co3O4-doped β-PbO2and TiO2/Co3O4-doped β-PbO2 composite electrodes were prepared on stainless steel by current electrodeposition.The morphology,elemental composition,structure and catalytic activity of the composite electrodes were characterized by SEM,EDS,XRD and electrodeposition.The results show that the doping of TiO2 refines crystal grains and increases surface area,and the doping of Co3O4 improves the catalytic activity of the oxygen evolution.Compared with Pb-Ag electrode,the β-PbO2-TiO2-Co3O4 composite anode has longer life,and the bath voltage was decreased to 2.97 V,and the current efficiency was increased to 91.2% in zinc electrowinng.
β-PbO2,TiO2-doped β-PbO2,Co3O4-doped β-PbO2and TiO2/Co3O4-doped β-PbO2 composite electrodes were prepared on stainless steel by current electrodeposition.The morphology,elemental composition,structure and catalytic activity of the composite electrodes were characterized by SEM,EDS,XRD and electrodeposition.The results show that the doping of TiO2 refines crystal grains and increases surface area,and the doping of Co3O4 improves the catalytic activity of the oxygen evolution.Compared with Pb-Ag electrode,the β-PbO2-TiO2-Co3O4 composite anode has longer life,and the bath voltage was decreased to 2.97 V,and the current efficiency was increased to 91.2% in zinc electrowinng.
2012, 29(6): 697-704
doi: 10.3724/SP.J.1095.2012.00314
Abstract:
A method on the separation and extraction of L-methionine(Met),L-leucine(Leu),L-phenylalanine(Phe),and L-tryptophan(Trp),using a strip dispersion hybrid liquid membrane(SDHLM) containing di-(2-ethylhexyl) phosphoric acid(D2EHPA) with kerosene as the organic liquid membrane phase and HCl solution as the aqueous strip solution,is developed.The effects of pH in the feed solution,the concentration of the carrier(D2EHPA),the volume ratio of the organic liquid membrane solution to the aqueous strip solution,the strip solution composition,the flow rates of the feed solution and the strip dispersion phase,the extraction time,and reuse times of the support membrane on the permeability coefficient and the transport efficiency of amino acids were investigated.Under the optimal conditions,the transport efficiencies obtained for the four amino acids,Met,Leu,Phe,and Trp were all higher than 35%,and more than 79% of transport efficiencies were obtained for Leu and Trp.The transport efficiency exhibits a trend of Et,Trp >Et,Leu >Et,Phe >Et,Met.With the 12 h-extraction time,the support membrane could be reused for at least 25 times with little decrease in the transport efficiency of amino acids.The developed method with high transport efficiency and excellent transport selectivity for the studied amino acids is simple and environmental friendly.
A method on the separation and extraction of L-methionine(Met),L-leucine(Leu),L-phenylalanine(Phe),and L-tryptophan(Trp),using a strip dispersion hybrid liquid membrane(SDHLM) containing di-(2-ethylhexyl) phosphoric acid(D2EHPA) with kerosene as the organic liquid membrane phase and HCl solution as the aqueous strip solution,is developed.The effects of pH in the feed solution,the concentration of the carrier(D2EHPA),the volume ratio of the organic liquid membrane solution to the aqueous strip solution,the strip solution composition,the flow rates of the feed solution and the strip dispersion phase,the extraction time,and reuse times of the support membrane on the permeability coefficient and the transport efficiency of amino acids were investigated.Under the optimal conditions,the transport efficiencies obtained for the four amino acids,Met,Leu,Phe,and Trp were all higher than 35%,and more than 79% of transport efficiencies were obtained for Leu and Trp.The transport efficiency exhibits a trend of Et,Trp >Et,Leu >Et,Phe >Et,Met.With the 12 h-extraction time,the support membrane could be reused for at least 25 times with little decrease in the transport efficiency of amino acids.The developed method with high transport efficiency and excellent transport selectivity for the studied amino acids is simple and environmental friendly.
2012, 29(6): 705-710
doi: 10.3724/SP.J.1095.2012.00326
Abstract:
Tiopronin(TP) capped with CdTe/CdS quantum dots(TP-CdTe/CdS QDs) was synthesized in aqueous solution.The paper utilized ultraviolet-visible(UV-Vis) absorption spectra and fluorescence spectrometry to study the interactions between TP-CdTe/CdS QDs and mitomycin C(MMC).With the optimum reaction conditions which was found to be at pH=7.6 with tris-HCl buffer solution,the quenched fluorescence intensity of TP-CdTe/CdS QDs was linearly proportional with the concentration of MMC,correlation coefficient r=0.9991,and the detection limits were in the range of 4.7×10-9~1.2×10-8 g/mL,and the detection limit(3σ) for MMC was 1.4×10-8 g/mL.The quantitative determination of MMC is quick,simple and convenient.This method has been applied to the determination of MMC in urine samples with satisfactory results.
Tiopronin(TP) capped with CdTe/CdS quantum dots(TP-CdTe/CdS QDs) was synthesized in aqueous solution.The paper utilized ultraviolet-visible(UV-Vis) absorption spectra and fluorescence spectrometry to study the interactions between TP-CdTe/CdS QDs and mitomycin C(MMC).With the optimum reaction conditions which was found to be at pH=7.6 with tris-HCl buffer solution,the quenched fluorescence intensity of TP-CdTe/CdS QDs was linearly proportional with the concentration of MMC,correlation coefficient r=0.9991,and the detection limits were in the range of 4.7×10-9~1.2×10-8 g/mL,and the detection limit(3σ) for MMC was 1.4×10-8 g/mL.The quantitative determination of MMC is quick,simple and convenient.This method has been applied to the determination of MMC in urine samples with satisfactory results.
2012, 29(6): 711-717
doi: 10.3724/SP.J.1095.2012.00323
Abstract:
Online Infrared spectrum was used for monitoring the reaction process of synthesizing octogen(HMX).The concentration profiles and spectra of reactants,intermediates and product were determined by analyzing the data using chemometric methods of multivariate curve resolution-alternating least squares(MCR-ALS) and heuristic evolving latent projection(HELP),and the reasonable mechanism was induced,which were coincided with literature.The results show that it is an effective means for researching the synthesizing reaction mechanism of octogen by chemometrics and infrared spectroscopy.
Online Infrared spectrum was used for monitoring the reaction process of synthesizing octogen(HMX).The concentration profiles and spectra of reactants,intermediates and product were determined by analyzing the data using chemometric methods of multivariate curve resolution-alternating least squares(MCR-ALS) and heuristic evolving latent projection(HELP),and the reasonable mechanism was induced,which were coincided with literature.The results show that it is an effective means for researching the synthesizing reaction mechanism of octogen by chemometrics and infrared spectroscopy.
2012, 29(6): 718-720
doi: 10.3724/SP.J.1095.2012.00354
Abstract:
Four porphyrin-5-fluorouracil conjugates,i.e.5-[3-(2-(5-fluorouracil-1-yl)-ethoxy)phenyl]-10,15,20-tri(3-chlorophenyl)porphyrin(1a),5-[3-(2-(5-fluorouracil-1-yl)-ethoxy)phenyl]-10,15,20-tri(3-chlorophenyl)Mn-porphyrin(2a),5-[3-(3-(5-fluorouracil-1-yl)-propoxy)phenyl]-10,15,20-tri(3-chlorophenyl)Mn-porphyrin(2b) and 5-[3-(4-(5-fluorouracil-1-yl)-butoxy)phenyl]-10,15,20-tri(3-chlorophenyl)Mn-porphyrin(2c),were successfully synthesized and characterized by UV-Vis,IR,MS and elemental analysis.Inhibition activity of the synthesized compounds(2a,2b and 2c) to human gastric cancer cell line BGC-823 was tested using the methyl thiazolyl tetrazolium(MTT) method.The IC50 value of 2b was 1.34 μmol/L,indicating that compound 2b had certain cytotoxic effect.
Four porphyrin-5-fluorouracil conjugates,i.e.5-[3-(2-(5-fluorouracil-1-yl)-ethoxy)phenyl]-10,15,20-tri(3-chlorophenyl)porphyrin(1a),5-[3-(2-(5-fluorouracil-1-yl)-ethoxy)phenyl]-10,15,20-tri(3-chlorophenyl)Mn-porphyrin(2a),5-[3-(3-(5-fluorouracil-1-yl)-propoxy)phenyl]-10,15,20-tri(3-chlorophenyl)Mn-porphyrin(2b) and 5-[3-(4-(5-fluorouracil-1-yl)-butoxy)phenyl]-10,15,20-tri(3-chlorophenyl)Mn-porphyrin(2c),were successfully synthesized and characterized by UV-Vis,IR,MS and elemental analysis.Inhibition activity of the synthesized compounds(2a,2b and 2c) to human gastric cancer cell line BGC-823 was tested using the methyl thiazolyl tetrazolium(MTT) method.The IC50 value of 2b was 1.34 μmol/L,indicating that compound 2b had certain cytotoxic effect.
2012, 29(6): 721-723
doi: 10.3724/SP.J.1095.2012.00567
Abstract:
Photofading behaviors of four water-soluble symmetrical squarylium indocyanine dyes with various substituents at N atom in aqueous solution containing different surfactants such as cetyltrimethylammonium bromide(CTAB),sodium dodecyl sulfate(SDS) and Triton X-100(TX-100) were investigated,respectively.The results showed that the effect of surfactants on photofading behaviors of dyes follows an order of CTAB >TX-100 >SDS.The dye with carboxyl group was affected most dramatically.At low concentration of CTAB,photofading degree of the dyes was increased with increasing concentration of CTAB.With the formation of micelles,photofading degree of the dyes was reduced with increasing concentration of CTAB.
Photofading behaviors of four water-soluble symmetrical squarylium indocyanine dyes with various substituents at N atom in aqueous solution containing different surfactants such as cetyltrimethylammonium bromide(CTAB),sodium dodecyl sulfate(SDS) and Triton X-100(TX-100) were investigated,respectively.The results showed that the effect of surfactants on photofading behaviors of dyes follows an order of CTAB >TX-100 >SDS.The dye with carboxyl group was affected most dramatically.At low concentration of CTAB,photofading degree of the dyes was increased with increasing concentration of CTAB.With the formation of micelles,photofading degree of the dyes was reduced with increasing concentration of CTAB.
2012, 29(6): 724-726
doi: 10.3724/SP.J.1095.2012.00385
Abstract:
3,4-Dimethoxy-4'-hydroxychalcone was synthesized by the Claisen-Schmidt condensation using 3,4-dimethoxybenzaldehyde and 4'-hydroxyacetophenone as reagents with ultrasonic radiation and dry HCl(g) as catalyst.The structure of the product was confirmed by IR and 1H NMR.The optimized synthesis conditions were to use anhydrous ethanol as the solvent,reaction temperature of 30℃,ultrasonic radiation of 240 W,and radiation time of 20 min.A yield of 92.1% was obtained for the reaction with 1: 1 stoichiometric ratio for the starting materials.Compared with previous method in the literature,the present procedure requires a shorter reaction time,and has easier work-up and higher yield.
3,4-Dimethoxy-4'-hydroxychalcone was synthesized by the Claisen-Schmidt condensation using 3,4-dimethoxybenzaldehyde and 4'-hydroxyacetophenone as reagents with ultrasonic radiation and dry HCl(g) as catalyst.The structure of the product was confirmed by IR and 1H NMR.The optimized synthesis conditions were to use anhydrous ethanol as the solvent,reaction temperature of 30℃,ultrasonic radiation of 240 W,and radiation time of 20 min.A yield of 92.1% was obtained for the reaction with 1: 1 stoichiometric ratio for the starting materials.Compared with previous method in the literature,the present procedure requires a shorter reaction time,and has easier work-up and higher yield.
2012, 29(6): 727-729
doi: 10.3724/SP.J.1095.2012.00438
Abstract:
The secondary metabolites of the medicinal mangrove endophytic fungus Penicillium sp.(ZZF29#) were firstly studied.Eight compounds were isolated from the ethyl acetate extract of the fermentation using silica gel column chromatography,preparative thin-layer chromatography and recrystallization.The structures of the compounds were identified as cyclo-(Phe-Ala)(1),cyclo-(Phe-Gly)(2),cyclo-(Phe-Phe)(3),cyclo-(Phe-Tyr)(4),emodin(5),physcion(6),ergosterol(7) and peroxide ergosterol(8),by comprehensive spectroscopic characterizations as well as comparison with reported data.
The secondary metabolites of the medicinal mangrove endophytic fungus Penicillium sp.(ZZF29#) were firstly studied.Eight compounds were isolated from the ethyl acetate extract of the fermentation using silica gel column chromatography,preparative thin-layer chromatography and recrystallization.The structures of the compounds were identified as cyclo-(Phe-Ala)(1),cyclo-(Phe-Gly)(2),cyclo-(Phe-Phe)(3),cyclo-(Phe-Tyr)(4),emodin(5),physcion(6),ergosterol(7) and peroxide ergosterol(8),by comprehensive spectroscopic characterizations as well as comparison with reported data.
2012, 29(6): 730-732
doi: 10.3724/SP.J.1095.2012.00307
Abstract:
Hydroxypropyl-β-cyclodextrins were applied to extract and enrich isoflavones which is the functional material in Belamcanda chinensis.The extracting time and temperature were studied and the process was optimized.The amount and the category of the extrtacted isoflavones were characterized by means of UV-Vis,HPLC and HPLC-MS.Under optimized conditions,the extracting amount of isoflavones was 2 times and the extracting amount of tectoridin was 3 times as those using water as the extractant.The as-established methodology is promising to be extended to the extraction research technology of Chinese traditional drugs.
Hydroxypropyl-β-cyclodextrins were applied to extract and enrich isoflavones which is the functional material in Belamcanda chinensis.The extracting time and temperature were studied and the process was optimized.The amount and the category of the extrtacted isoflavones were characterized by means of UV-Vis,HPLC and HPLC-MS.Under optimized conditions,the extracting amount of isoflavones was 2 times and the extracting amount of tectoridin was 3 times as those using water as the extractant.The as-established methodology is promising to be extended to the extraction research technology of Chinese traditional drugs.
