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2012 Volume 29 Issue 3
2012, 29(3): 245-250
doi: 10.3724/SP.J.1095.2012.00148
Abstract:
The development of the electrolytes in the current-type electrochemical gas sensor is summarized.It was found that using the ionic liquid as the electrolyte has many advantages,such as non-volatilization,high conductivity,wide electrochemical window etc,compared to the aqueous solution.Combined ionic liquid with the polymer,the obtained ionic liquid/polymer electrolyte possesses both the advantages of the ionic liquid and polymer.Thus,it has the excellent application prospect.The investigation about using the organic solvent as the electrolyte in the current-type electrochemical gas sensor is just beginning.Moreover,it is also a promising route.
The development of the electrolytes in the current-type electrochemical gas sensor is summarized.It was found that using the ionic liquid as the electrolyte has many advantages,such as non-volatilization,high conductivity,wide electrochemical window etc,compared to the aqueous solution.Combined ionic liquid with the polymer,the obtained ionic liquid/polymer electrolyte possesses both the advantages of the ionic liquid and polymer.Thus,it has the excellent application prospect.The investigation about using the organic solvent as the electrolyte in the current-type electrochemical gas sensor is just beginning.Moreover,it is also a promising route.
2012, 29(3): 251-255
doi: 10.3724/SP.J.1095.2012.00193
Abstract:
Graphene composites have been prepared in this paper through the reaction between the amine group of 1-H,1-H-pentadecafluorooctylamine(FOA) and the carboxyl or alkoxy of graphene oxide(GO).The structures of the resulted composites were characterized by the means of FT-IR infrared spectrum,thermogravimetric analyzer,Raman microscope,high resolution transmission electron microscope,and atomic force microscope.The results indicated that the FOA molecule was linked to the edge of graphene.Meanwhile,the contact angle of the FOA-RGO composites was increased to 118° at room temperature compared with that of RGO(68°).
Graphene composites have been prepared in this paper through the reaction between the amine group of 1-H,1-H-pentadecafluorooctylamine(FOA) and the carboxyl or alkoxy of graphene oxide(GO).The structures of the resulted composites were characterized by the means of FT-IR infrared spectrum,thermogravimetric analyzer,Raman microscope,high resolution transmission electron microscope,and atomic force microscope.The results indicated that the FOA molecule was linked to the edge of graphene.Meanwhile,the contact angle of the FOA-RGO composites was increased to 118° at room temperature compared with that of RGO(68°).
2012, 29(3): 256-259
doi: 10.3724/SP.J.1095.2012.00184
Abstract:
Starch/lactic acid graft copolymer was prepared with in-stiu graft copolymerization catalyzed by zinc oxide.The graft copolymer was characterized by FT-IR,1H NMR,XRD and SEM.Effects of the reaction temperature,mass ratio between corn starch and lactic acid,amount of the catalyst and the reaction time on the grafting degree were studied.It was found that the highest grafting degree could reach 14.20% with the mass ratio of corn starch to lactic acid being 5:1,and the mass fraction of the catalyst being 1.0% of the lactic acid,and the reaction was carried out at 95℃ for 11 h.
Starch/lactic acid graft copolymer was prepared with in-stiu graft copolymerization catalyzed by zinc oxide.The graft copolymer was characterized by FT-IR,1H NMR,XRD and SEM.Effects of the reaction temperature,mass ratio between corn starch and lactic acid,amount of the catalyst and the reaction time on the grafting degree were studied.It was found that the highest grafting degree could reach 14.20% with the mass ratio of corn starch to lactic acid being 5:1,and the mass fraction of the catalyst being 1.0% of the lactic acid,and the reaction was carried out at 95℃ for 11 h.
2012, 29(3): 260-265
doi: 10.3724/SP.J.1095.2012.00292
Abstract:
Polystyrene(PS) was modified with 4-(chloromethyl) benzoic acid(CMBA) via Friedel-Crafts alkylation reaction,where benzoic acid(BA) ligand was bonded on the side chains of PS,yielding the functional macromolecule BAPS.The chemical structure of BAPS was characterized by FTIR,1H NMR and UV absorption spectra.The coordination reaction between BAPS and Eu3+ ion as well as the coordination reaction between BAPS and Tb3+ ion were carried out,resulting in the polymer/rare-earth complexes,BAPS-Tb(Ⅲ).The florescence emission of BAPS-Tb(Ⅲ) was preliminarily examined.In this work,the effects of the main factors on the Friedel-Crafts alkylation action between CMBA and PS were examined,the reaction mechanism was investigated,and the reaction conditions were optimized.The experimental results show that the Friedel-Crafts alkylation reaction between CMBA and PS can proceed successfully,and the suitable reaction conditions are as follows:a temperature of 70℃,with N,N-dimethylacetylamide(DMAC) as solvent,and SnCl4 as Lewis catalyst.The polymer/rare-earth complex BAPS-Tb(Ⅲ),possesses the fluorescence-emission spectrum of Tb3+ ion.More significantly,the macromolecular ligand BAPS can strongly sensitize the fluorescence-emission of Tb3+ ion.
Polystyrene(PS) was modified with 4-(chloromethyl) benzoic acid(CMBA) via Friedel-Crafts alkylation reaction,where benzoic acid(BA) ligand was bonded on the side chains of PS,yielding the functional macromolecule BAPS.The chemical structure of BAPS was characterized by FTIR,1H NMR and UV absorption spectra.The coordination reaction between BAPS and Eu3+ ion as well as the coordination reaction between BAPS and Tb3+ ion were carried out,resulting in the polymer/rare-earth complexes,BAPS-Tb(Ⅲ).The florescence emission of BAPS-Tb(Ⅲ) was preliminarily examined.In this work,the effects of the main factors on the Friedel-Crafts alkylation action between CMBA and PS were examined,the reaction mechanism was investigated,and the reaction conditions were optimized.The experimental results show that the Friedel-Crafts alkylation reaction between CMBA and PS can proceed successfully,and the suitable reaction conditions are as follows:a temperature of 70℃,with N,N-dimethylacetylamide(DMAC) as solvent,and SnCl4 as Lewis catalyst.The polymer/rare-earth complex BAPS-Tb(Ⅲ),possesses the fluorescence-emission spectrum of Tb3+ ion.More significantly,the macromolecular ligand BAPS can strongly sensitize the fluorescence-emission of Tb3+ ion.
2012, 29(3): 266-269
doi: 10.3724/SP.J.1095.2012.00138
Abstract:
D-Glucoheptulose was synthesized by iodomethylation using D-glucolactone as the starting material.Firstly,2,3,4,6-tetra-O-trimethylsilanyl-D-glucolactone was prepared from D-glucolactone under the catalyst of N-methylmorpholine,with a yield of 95%.Secondly,2,7-dehydrate-β-D-glucoheptulopyranose was synthesized by addition of iodomethyl lithium generated from CH2I2/n-BuLi to the carbonyl group of lactone,and then hydrolysis under basic conditions,with a yield of 62%.Finally,D-glucoheptulose was prepared by hydrolysis under acidic conditions,with a yield of 90%(total yield 53%).The acetylated products of the target compound D-glucoheptulose and the key intermediate 2,7-dehydrate-β-D-glucoheptulopyranose were characterized by NMR.
D-Glucoheptulose was synthesized by iodomethylation using D-glucolactone as the starting material.Firstly,2,3,4,6-tetra-O-trimethylsilanyl-D-glucolactone was prepared from D-glucolactone under the catalyst of N-methylmorpholine,with a yield of 95%.Secondly,2,7-dehydrate-β-D-glucoheptulopyranose was synthesized by addition of iodomethyl lithium generated from CH2I2/n-BuLi to the carbonyl group of lactone,and then hydrolysis under basic conditions,with a yield of 62%.Finally,D-glucoheptulose was prepared by hydrolysis under acidic conditions,with a yield of 90%(total yield 53%).The acetylated products of the target compound D-glucoheptulose and the key intermediate 2,7-dehydrate-β-D-glucoheptulopyranose were characterized by NMR.
2012, 29(3): 270-274
doi: 10.3724/SP.J.1095.2012.00228
Abstract:
Using prenal and prenol as precursors,3-methyl-2-butenal diprenyl acetal was obtained via an acetalization reaction using senecioic acid as catalyst.Then an elimination of 3-methyl-2-butenal diprenyl acetal catalyzed by ammonium dihydrogen phosphate yielded the cis/trans-prenyl-3-methyl-butadienyl ether.Further rearrangement of the elimination product through heating produced to the target citral.The conditions of acetalization reaction and elimination reaction were optimized.It was found that a conversion yield of 63%~64% for prenal could be achieved at 70~75℃ for 8 h with 0.3% senecioic acid as catalyst.After azeotropism treatment,the purity and yield of 3-methyl-2-butenal diprenyl acetal are 97.5% and 96.8%,respectively.Using 0.2%~0.5% ammonium dihydrogen phosphate as catalyst,the elimination reaction was carried out at 100~130℃ and 2.66 kPa.The cis/trans-prenyl-3-methylbutadienyl ether was distilled from the reaction batch and its purity and yield are 95.9% and 97.0%,respectively.The rearrangement reaction temperature was 120~130℃,the purity and yield of citral are 97.5% and 90.2%,respectively.
Using prenal and prenol as precursors,3-methyl-2-butenal diprenyl acetal was obtained via an acetalization reaction using senecioic acid as catalyst.Then an elimination of 3-methyl-2-butenal diprenyl acetal catalyzed by ammonium dihydrogen phosphate yielded the cis/trans-prenyl-3-methyl-butadienyl ether.Further rearrangement of the elimination product through heating produced to the target citral.The conditions of acetalization reaction and elimination reaction were optimized.It was found that a conversion yield of 63%~64% for prenal could be achieved at 70~75℃ for 8 h with 0.3% senecioic acid as catalyst.After azeotropism treatment,the purity and yield of 3-methyl-2-butenal diprenyl acetal are 97.5% and 96.8%,respectively.Using 0.2%~0.5% ammonium dihydrogen phosphate as catalyst,the elimination reaction was carried out at 100~130℃ and 2.66 kPa.The cis/trans-prenyl-3-methylbutadienyl ether was distilled from the reaction batch and its purity and yield are 95.9% and 97.0%,respectively.The rearrangement reaction temperature was 120~130℃,the purity and yield of citral are 97.5% and 90.2%,respectively.
2012, 29(3): 275-279
doi: 10.3724/SP.J.1095.2012.00205
Abstract:
A home-made reactor possessing functions including reaction,blending,bubbling,protecting with N2 and filtration was fabricated.The effects of the type of resin,solvent,coupling reagent and reaction time on the yield of cyclic eptifibatide were investigated.The results showed the overall yield was up to 86.6%,using Rink Amide AM resin as solid supporter,HBTU/HOBt/DIEA as the coupling reagent,DMF as the solvent and reaction 2 hours in the reactor.The purity of the product as revealed by HPLC could reach 98%.
A home-made reactor possessing functions including reaction,blending,bubbling,protecting with N2 and filtration was fabricated.The effects of the type of resin,solvent,coupling reagent and reaction time on the yield of cyclic eptifibatide were investigated.The results showed the overall yield was up to 86.6%,using Rink Amide AM resin as solid supporter,HBTU/HOBt/DIEA as the coupling reagent,DMF as the solvent and reaction 2 hours in the reactor.The purity of the product as revealed by HPLC could reach 98%.
2012, 29(3): 280-284
doi: 10.3724/SP.J.1095.2012.00194
Abstract:
A β-diketone ligand L(3-(4,4,4-trifluorobutane-1,3-diketone)-9-butylcarbazole) was synthesized according to literature method.The copper(Ⅰ) complex with fluorescent activity was prepared by the reaction of copper nitrate,copper,triphenylphosphine and L,which was characterized by elemental analysis and IR spectra.Its crystal structure was determined by single crystal X-ray diffraction analysis.The crystal belongs to monoclinic,P21/c space group.Cell parameters:a=1.6428(5) nm,b=1.0434(5) nm,c=2.8001(5) nm,V=4.800(3) nm3,Z=4,Dc=1.313 Mg/m3,R[I>2σ(I)] R1=0.0501,wR2=0.0808.The Cu(Ⅰ) ion in the distorted tetrahedral copper(Ⅰ) complex is coordinated by two O atoms from the two β-diketone ligands,and two P atoms from triphenylphosphine,respectively.Fluorescent properties of the copper(Ⅰ) complex were studied,which indicated that the complex had strong fluorescent emission in dichloromethane solution.
A β-diketone ligand L(3-(4,4,4-trifluorobutane-1,3-diketone)-9-butylcarbazole) was synthesized according to literature method.The copper(Ⅰ) complex with fluorescent activity was prepared by the reaction of copper nitrate,copper,triphenylphosphine and L,which was characterized by elemental analysis and IR spectra.Its crystal structure was determined by single crystal X-ray diffraction analysis.The crystal belongs to monoclinic,P21/c space group.Cell parameters:a=1.6428(5) nm,b=1.0434(5) nm,c=2.8001(5) nm,V=4.800(3) nm3,Z=4,Dc=1.313 Mg/m3,R[I>2σ(I)] R1=0.0501,wR2=0.0808.The Cu(Ⅰ) ion in the distorted tetrahedral copper(Ⅰ) complex is coordinated by two O atoms from the two β-diketone ligands,and two P atoms from triphenylphosphine,respectively.Fluorescent properties of the copper(Ⅰ) complex were studied,which indicated that the complex had strong fluorescent emission in dichloromethane solution.
2012, 29(3): 285-290
doi: 10.3724/SP.J.1095.2012.00217
Abstract:
The sulfur-doped titanate and sodium titanate nanotubes(STNTs) were prepared by hydrothermal reaction of sodium hydroxide(NaOH) with titanium disulphide(TiS2),which was used as sulfur source and titanium source for the first time.The structure,morphology,sulfur-doped valence state and doped amount of the as-obtained STNTs were characterized by X-ray diffraction(XRD),high resolution transmission electron microscopy(HRTEM),scanning electron microscope(SEM),extended X-ray absorption fine structure(EXAFS),and energy dispersive X-ray(EDS).The photo-oxidation reaction of ethanol under visible light was used to probe the reaction,and the visible light-responsive photocatalytic activity of sulfur-doped titanate nanotube was investigated by means of in-situ gas chromatography(GC).The results indicated that S atoms were introduced into the lattice of titanate nanotubes as S2-anions.The average size of wall thickness and diameter of STNTs were 2.9 nm and 9.7 nm,respectively.The visible light-responsive photocatalytic oxidation results indicated that the SNTTs with very low amount of doped sulfur showed higher photocatalytic activity than undoped TiO2 nanotubes.
The sulfur-doped titanate and sodium titanate nanotubes(STNTs) were prepared by hydrothermal reaction of sodium hydroxide(NaOH) with titanium disulphide(TiS2),which was used as sulfur source and titanium source for the first time.The structure,morphology,sulfur-doped valence state and doped amount of the as-obtained STNTs were characterized by X-ray diffraction(XRD),high resolution transmission electron microscopy(HRTEM),scanning electron microscope(SEM),extended X-ray absorption fine structure(EXAFS),and energy dispersive X-ray(EDS).The photo-oxidation reaction of ethanol under visible light was used to probe the reaction,and the visible light-responsive photocatalytic activity of sulfur-doped titanate nanotube was investigated by means of in-situ gas chromatography(GC).The results indicated that S atoms were introduced into the lattice of titanate nanotubes as S2-anions.The average size of wall thickness and diameter of STNTs were 2.9 nm and 9.7 nm,respectively.The visible light-responsive photocatalytic oxidation results indicated that the SNTTs with very low amount of doped sulfur showed higher photocatalytic activity than undoped TiO2 nanotubes.
2012, 29(3): 291-296
doi: 10.3724/SP.J.1095.2012.00206
Abstract:
A visible-light responsible non-metal C-N-S-tertiary doped TiO2 was synthesized by a sol-gel process using Ti(OC4H9)4 and functional biology organic cystine as raw materials.The obtained photocatalysts were characterized by the means of X-ray powder diffraction(XRD),X-ray photoelectron spectroscopy(XPS),fourier transition infrared spectra(FT-IR),ultraviolet-visible diffuse reflectance spectroscopy(UV-Vis DRS).XRD showed that,by C,N and S tertiary-doping,the growth of TiO2 crystallite was restrained and the temperature of phase transformation from anatase to rutile of TiO2 was enhanced effectively.DRS showed the extension of light absorption edge in the range of visible-light was up to 800 nm.XPS analysis revealed that C and S existing on the surface of TiO2 photocatalyst was the state of CO32- and S6+,respectively.Nitrogen species could be ascribed to the form of N-Ti-O and Ti-O-N.And more hydroxyl groups were found on the C-N-S tertiary doped catalyst.The photocatalytic activities of the as-prepared photocatalysts were evaluated by degradation of Rhodamine B(RhB) in an aqueous suspension under visible light.It was found that C-N-S- tertiary doped TiO2 exhibited improved photocatalytic activity compared with that of P25 TiO2.Under the visible-light irradiation ranging from 470 to 800 nm for 2 h,an 83% removal rate of RhB could be achieved.
A visible-light responsible non-metal C-N-S-tertiary doped TiO2 was synthesized by a sol-gel process using Ti(OC4H9)4 and functional biology organic cystine as raw materials.The obtained photocatalysts were characterized by the means of X-ray powder diffraction(XRD),X-ray photoelectron spectroscopy(XPS),fourier transition infrared spectra(FT-IR),ultraviolet-visible diffuse reflectance spectroscopy(UV-Vis DRS).XRD showed that,by C,N and S tertiary-doping,the growth of TiO2 crystallite was restrained and the temperature of phase transformation from anatase to rutile of TiO2 was enhanced effectively.DRS showed the extension of light absorption edge in the range of visible-light was up to 800 nm.XPS analysis revealed that C and S existing on the surface of TiO2 photocatalyst was the state of CO32- and S6+,respectively.Nitrogen species could be ascribed to the form of N-Ti-O and Ti-O-N.And more hydroxyl groups were found on the C-N-S tertiary doped catalyst.The photocatalytic activities of the as-prepared photocatalysts were evaluated by degradation of Rhodamine B(RhB) in an aqueous suspension under visible light.It was found that C-N-S- tertiary doped TiO2 exhibited improved photocatalytic activity compared with that of P25 TiO2.Under the visible-light irradiation ranging from 470 to 800 nm for 2 h,an 83% removal rate of RhB could be achieved.
2012, 29(3): 297-303
doi: 10.3724/SP.J.1095.2012.00175
Abstract:
Super-hydrophobic filter papers were prepared by using SiO2 nano-particles midified by silylating reagent.The water contact angle on the filter papers was higher than 150°.Thermogravimetry and scanning electron microscope were used to characterize the filter paper.The results showed that SiO2 nano-particle layer was formed on the micro-fibers of filter paper.The combined nano-and micro-structure produced the super-hydrophobic property of the filter paper.The oil-water separation ability of the paper was also investigated,high oil-water separation efficiencies of the paper,especially for high-viscosity mixtures,were confirmed.
Super-hydrophobic filter papers were prepared by using SiO2 nano-particles midified by silylating reagent.The water contact angle on the filter papers was higher than 150°.Thermogravimetry and scanning electron microscope were used to characterize the filter paper.The results showed that SiO2 nano-particle layer was formed on the micro-fibers of filter paper.The combined nano-and micro-structure produced the super-hydrophobic property of the filter paper.The oil-water separation ability of the paper was also investigated,high oil-water separation efficiencies of the paper,especially for high-viscosity mixtures,were confirmed.
2012, 29(3): 304-310
doi: 10.3724/SP.J.1095.2012.00168
Abstract:
The synthesized and purified cucurbit[7]uril(CB[7]) was coated on a 102 white celite carrier under acidic conditions as a new gas chromatography(GC) stationary phase.The chemical structure of the CB[7] was characterized by infrared spectroscopy,mass spectrometry,elemental analysis and thermogravity analysis.The McReynolds constants of the new stationary phases were determined by using different probes in order to characterize its basic chromatographic property.The separation abilities of some aromatic hydrocarbons,halohydrocarbons,alcohols,ketones,esters,siloxanes were investigated on the packed column of CB[7] coated stationary phase,respectively.The results showed that new CB[7] stationary phase exhibited not only a good thermal stability and also a better separation selectivity for different analytes,indicating that the CB[7] stationary phase has a great potential in GC separations.Especially,some high boiling point esters and siloxanes can be successfully separated within 7 min.Additionally,the retention mechanism of the CB[7] stationary phase was also discussed.
The synthesized and purified cucurbit[7]uril(CB[7]) was coated on a 102 white celite carrier under acidic conditions as a new gas chromatography(GC) stationary phase.The chemical structure of the CB[7] was characterized by infrared spectroscopy,mass spectrometry,elemental analysis and thermogravity analysis.The McReynolds constants of the new stationary phases were determined by using different probes in order to characterize its basic chromatographic property.The separation abilities of some aromatic hydrocarbons,halohydrocarbons,alcohols,ketones,esters,siloxanes were investigated on the packed column of CB[7] coated stationary phase,respectively.The results showed that new CB[7] stationary phase exhibited not only a good thermal stability and also a better separation selectivity for different analytes,indicating that the CB[7] stationary phase has a great potential in GC separations.Especially,some high boiling point esters and siloxanes can be successfully separated within 7 min.Additionally,the retention mechanism of the CB[7] stationary phase was also discussed.
2012, 29(3): 311-315
doi: 10.3724/SP.J.1095.2012.00156
Abstract:
The volatile constituents of Lindera Pulcherrima(Wall.) were extracted by steam distillation.The chemical constituents of essential oil have been analyzed by GC-MS.The results show that the extractive yield of essential oil is 0.75%,the compounds of essential oil are 28.94% eucalyptol,15.75% α-methlybenzofuran,5.13% 4-terpinenol,11.22% α-terpineol,7.97% 2-hydroxycinnamic acid,2.87% guaiol,and the extractive yield of substance from water is 0.25%,which consists of 8.47% 2-methylbenzofuran,24.13% 2H-1-benzopyran-2-one,18.07% 2H-1-benzopyran-3-ol,3,4-dihydro-,acetate,2.09% p-gresyl glycidyl ether,4.50% 1-phenylpropene-3,3-diol diacetate,17.19% glycerol dicetate and 11.80% farnesyl acetate.
The volatile constituents of Lindera Pulcherrima(Wall.) were extracted by steam distillation.The chemical constituents of essential oil have been analyzed by GC-MS.The results show that the extractive yield of essential oil is 0.75%,the compounds of essential oil are 28.94% eucalyptol,15.75% α-methlybenzofuran,5.13% 4-terpinenol,11.22% α-terpineol,7.97% 2-hydroxycinnamic acid,2.87% guaiol,and the extractive yield of substance from water is 0.25%,which consists of 8.47% 2-methylbenzofuran,24.13% 2H-1-benzopyran-2-one,18.07% 2H-1-benzopyran-3-ol,3,4-dihydro-,acetate,2.09% p-gresyl glycidyl ether,4.50% 1-phenylpropene-3,3-diol diacetate,17.19% glycerol dicetate and 11.80% farnesyl acetate.
2012, 29(3): 316-319
doi: 10.3724/SP.J.1095.2012.00160
Abstract:
The reaction between ampicillin sodium and ninhydrin was investigated by spectrophotometry.A simple and rapid method for the determination of ampicillin sodium has been optimized.The apparent molar absorptivity of complex is 3.72×103 L/(mol·cm) at 564 nm.Beer's law could be followed in the range of 10~90 mg/L of ampicillin sodium with correlation coefficient of 0.998 1.The relative standard deviation is 1.5%(n=6) and the recovery was over 99.0%.
The reaction between ampicillin sodium and ninhydrin was investigated by spectrophotometry.A simple and rapid method for the determination of ampicillin sodium has been optimized.The apparent molar absorptivity of complex is 3.72×103 L/(mol·cm) at 564 nm.Beer's law could be followed in the range of 10~90 mg/L of ampicillin sodium with correlation coefficient of 0.998 1.The relative standard deviation is 1.5%(n=6) and the recovery was over 99.0%.
2012, 29(3): 320-326
doi: 10.3724/SP.J.1095.2012.00163
Abstract:
The mercaptoacetic acid(TGA) stabilized core-shell CdTe/CdS quantum dots(TGA-CdTe/CdS QDs) were synthesized using as stabilizer.A new method for the determination of jatrorrhizine hydrochloride has been developed based on the quenching of the fluorescence of TGA-CdTe/CdS QDs at excitation wavelength of 340 nm.The paper utilized fluorescence spectrometry and ultraviolet-visible(UV-Vis) absorption spectra to study the interaction between TGA-CdTe/CdS QDs and jatrorrhizine hydrochloride(JH).Under optimized conditions,in which at the pH value is 7.4 using tris-HCl buffer solution,the quenched fluorescence intensity of TGA-CdTe/CdS QDs was linearly proportional with a correlation coefficient r=0.9991,and the limits of detection were in the range of 0.011~10 mg/L and the detection limit for JH(3σ) was 3.3×10-3 mg/L.JH could be conveniently and quantitatively detemined using this new method.
The mercaptoacetic acid(TGA) stabilized core-shell CdTe/CdS quantum dots(TGA-CdTe/CdS QDs) were synthesized using as stabilizer.A new method for the determination of jatrorrhizine hydrochloride has been developed based on the quenching of the fluorescence of TGA-CdTe/CdS QDs at excitation wavelength of 340 nm.The paper utilized fluorescence spectrometry and ultraviolet-visible(UV-Vis) absorption spectra to study the interaction between TGA-CdTe/CdS QDs and jatrorrhizine hydrochloride(JH).Under optimized conditions,in which at the pH value is 7.4 using tris-HCl buffer solution,the quenched fluorescence intensity of TGA-CdTe/CdS QDs was linearly proportional with a correlation coefficient r=0.9991,and the limits of detection were in the range of 0.011~10 mg/L and the detection limit for JH(3σ) was 3.3×10-3 mg/L.JH could be conveniently and quantitatively detemined using this new method.
2012, 29(3): 327-331
doi: 10.3724/SP.J.1095.2012.00158
Abstract:
Effects of dispersants and mass fraction on the physical stability of ametryne suspension concentrate were studied by the average particle size measurement and morphology characterization.The results showed that maleic rosin-polyoxypropylene-polyoxyethylene ether sulfonate(SC-3) formed double-layer adsorption on the surface layer of pesticide,resulting in two-layer static shield system.This system could effectively prevent the particles and water from contacting with each other,inhibiting particle agglomeration and crystal growth by Ostwald ripening.The average particle size and the particle morphology changed little after heat storage due to the restraint of crystal growth.The best physical stability was achieved when the dosage of SC-3 was over 4%.
Effects of dispersants and mass fraction on the physical stability of ametryne suspension concentrate were studied by the average particle size measurement and morphology characterization.The results showed that maleic rosin-polyoxypropylene-polyoxyethylene ether sulfonate(SC-3) formed double-layer adsorption on the surface layer of pesticide,resulting in two-layer static shield system.This system could effectively prevent the particles and water from contacting with each other,inhibiting particle agglomeration and crystal growth by Ostwald ripening.The average particle size and the particle morphology changed little after heat storage due to the restraint of crystal growth.The best physical stability was achieved when the dosage of SC-3 was over 4%.
Stability Mechanism of Lambda-Cyhalothrin O/W Emulsion Prepared with Esterified Starch as Emulsifier
2012, 29(3): 332-339
doi: 10.3724/SP.J.1095.2012.00059
Abstract:
The stability mechanism of 5%(w/w) lambda-cyhalothrin O/W emulsion prepared with octenyl succinic anhydride(OSA)-modified starch as emulsifier was studied.For this purpose,the effects of OSA-modified starch content,inorganic ions,pH value and temperature on the Zeta potential of oil droplets and surface loads(Γ) of modified starch were investigated.When the OSA-modified starch content was 7%(mass fraction),Zeta potential could reach the maximum,and Γ appear to reach saturation level;Na+,Mg2+ and Al3+ were able to decrease Zeta potential by compressing the electronic double layer thickness of oil droplet surface,which could lead to the enhancement of molecular flexibility due to the weakened electrostatic exclusion and make Γ enlarger.With the increasing of ionic strength,the capacity of compressing the electronic double layer thickness of oil droplet surface was subsequently enhanced by Na+,Mg2+ and Al3+,and the degrees of Zeta potential reduction and Γ increment were obvious in the sequence of Na+,Mg2+ and Al3+.As the pH affected the ionization of OSA-modified starch in water,in the range of alkaline,strong electrostatic repulsive force was provided by more ionized carboxylic ions and the Zeta potential increased while the Γ decreased.As temperature increased,the solubility or escaping tendency of OSA-modified starch increased,so the Zeta potential and Γ decreased,furthermore the difference was not obvious at low temperatures,but at higher temperature it was,the less the Zeta potential and surface load(Γ) was.The OSA-modified starch that was adsorbed at the oil droplets surface was able to stabilize the emulsion by very strong electrostatic exclusion and steric-hindrance double effect.
The stability mechanism of 5%(w/w) lambda-cyhalothrin O/W emulsion prepared with octenyl succinic anhydride(OSA)-modified starch as emulsifier was studied.For this purpose,the effects of OSA-modified starch content,inorganic ions,pH value and temperature on the Zeta potential of oil droplets and surface loads(Γ) of modified starch were investigated.When the OSA-modified starch content was 7%(mass fraction),Zeta potential could reach the maximum,and Γ appear to reach saturation level;Na+,Mg2+ and Al3+ were able to decrease Zeta potential by compressing the electronic double layer thickness of oil droplet surface,which could lead to the enhancement of molecular flexibility due to the weakened electrostatic exclusion and make Γ enlarger.With the increasing of ionic strength,the capacity of compressing the electronic double layer thickness of oil droplet surface was subsequently enhanced by Na+,Mg2+ and Al3+,and the degrees of Zeta potential reduction and Γ increment were obvious in the sequence of Na+,Mg2+ and Al3+.As the pH affected the ionization of OSA-modified starch in water,in the range of alkaline,strong electrostatic repulsive force was provided by more ionized carboxylic ions and the Zeta potential increased while the Γ decreased.As temperature increased,the solubility or escaping tendency of OSA-modified starch increased,so the Zeta potential and Γ decreased,furthermore the difference was not obvious at low temperatures,but at higher temperature it was,the less the Zeta potential and surface load(Γ) was.The OSA-modified starch that was adsorbed at the oil droplets surface was able to stabilize the emulsion by very strong electrostatic exclusion and steric-hindrance double effect.
2012, 29(3): 340-345
doi: 10.3724/SP.J.1095.2012.00197
Abstract:
A pH-sensitive monomethoxypoly(ethylene glycol)-grafted-chitosan(mPEG-g-CS) film was used as a matrix for reversible immobilization of cytochrome c(Cyt c) on a Au surface through a novel electrodeposition process.The pH-sensitive behavior of the mPEG-g-CS film was demonstrated by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS) measurements.Electrochemical co-deposited Cyt c and mPEG-g-CS exhibited the direct electrochemical behavior which implied that mPEG-g-CS could well control the delivery of Cyt c under different pH.
A pH-sensitive monomethoxypoly(ethylene glycol)-grafted-chitosan(mPEG-g-CS) film was used as a matrix for reversible immobilization of cytochrome c(Cyt c) on a Au surface through a novel electrodeposition process.The pH-sensitive behavior of the mPEG-g-CS film was demonstrated by cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS) measurements.Electrochemical co-deposited Cyt c and mPEG-g-CS exhibited the direct electrochemical behavior which implied that mPEG-g-CS could well control the delivery of Cyt c under different pH.
2012, 29(3): 346-352
doi: 10.3724/SP.J.1095.2012.00153
Abstract:
A novel Fe3O4 nanoparticles modified glassy carbon electrode(Fe3O4-np/GC electrode) was fabricated via a dropwise-coating method.The XRD pattern indicated that the Fe3O4 nanoparticles have pure cubic phase spinel structure,and the TEM image showed that the Fe3O4 nanoparticles are tiny spherical particles with mean size of 15~20 nm.The microstructure and electrochemical behavior of the modified electrode were investigated by scanning electron microscope(SEM) and electrochemical impedance spectrum(EIS).The electrochemical behaviors and kinetic parameters of cefotaxime sodium(CS) on Fe3O4-np/GC electrode were investigated by cyclic voltammetry(CV) and differential pulse voltammetry(DPV).The experimental results showed that the reduction peak current of CS increased significantly at modified electrode in comparison with that at GC electrode.In B-R buffer solution,the reduction peak currents are proportional to the concentrations of CS over the range from 7.0×10-8 to 1×10-6 and 1×10-6 to 4.5×10-5 mol/L,respectively,and the limit of detection is 5.0×10-8 mol/L.This method was applied in the determination of CS in four kinds of commercial injection samples and the recovery varies from 96.6% to 102.7%.
A novel Fe3O4 nanoparticles modified glassy carbon electrode(Fe3O4-np/GC electrode) was fabricated via a dropwise-coating method.The XRD pattern indicated that the Fe3O4 nanoparticles have pure cubic phase spinel structure,and the TEM image showed that the Fe3O4 nanoparticles are tiny spherical particles with mean size of 15~20 nm.The microstructure and electrochemical behavior of the modified electrode were investigated by scanning electron microscope(SEM) and electrochemical impedance spectrum(EIS).The electrochemical behaviors and kinetic parameters of cefotaxime sodium(CS) on Fe3O4-np/GC electrode were investigated by cyclic voltammetry(CV) and differential pulse voltammetry(DPV).The experimental results showed that the reduction peak current of CS increased significantly at modified electrode in comparison with that at GC electrode.In B-R buffer solution,the reduction peak currents are proportional to the concentrations of CS over the range from 7.0×10-8 to 1×10-6 and 1×10-6 to 4.5×10-5 mol/L,respectively,and the limit of detection is 5.0×10-8 mol/L.This method was applied in the determination of CS in four kinds of commercial injection samples and the recovery varies from 96.6% to 102.7%.
2012, 29(3): 353-358
doi: 10.3724/SP.J.1095.2012.00164
Abstract:
The electrocatalytic oxidation and electrochemical kinetics of bisphenol A(BPA) were investigated at sodium dodecyl sulphate(SDS) self-assembled monolayer and N-butylpyridinium hexafluorophosphate(PF6) modified carbon paste electrode(CPE).The experimental results indicated that BPA electrochemical behavior exhibited an irreversible electrochemical oxidation process at SDS-PF6/CPE.The electrochemical kinetic parameters were determined by cyclic voltammetry(CV),chronoamperometry(CA).The oxidation peak current of BPA had a good linear relationship with the concentration of BPA in the range of 1.0×10-5~1.0×10-3 mol/L with a correlation coefficient of 0.9981,and a detection limit of 3.01×10-7 mol/L(S/N=3) was obtained by square wave voltammetry(SWV).The method was applied to determine quantitative BPA content in lake water samples with satisfactory results.
The electrocatalytic oxidation and electrochemical kinetics of bisphenol A(BPA) were investigated at sodium dodecyl sulphate(SDS) self-assembled monolayer and N-butylpyridinium hexafluorophosphate(PF6) modified carbon paste electrode(CPE).The experimental results indicated that BPA electrochemical behavior exhibited an irreversible electrochemical oxidation process at SDS-PF6/CPE.The electrochemical kinetic parameters were determined by cyclic voltammetry(CV),chronoamperometry(CA).The oxidation peak current of BPA had a good linear relationship with the concentration of BPA in the range of 1.0×10-5~1.0×10-3 mol/L with a correlation coefficient of 0.9981,and a detection limit of 3.01×10-7 mol/L(S/N=3) was obtained by square wave voltammetry(SWV).The method was applied to determine quantitative BPA content in lake water samples with satisfactory results.
2012, 29(3): 359-363
doi: 10.3724/SP.J.1095.2012.00171
Abstract:
The influences of 6-nitrobenzimidazole,benzimidazole and Pb2+ on zinc dendrite in KOH solution(4 mol/L) were investigated by means of current-time technique.The results showed that 6-nitrobenzimidazole,benzimidazole and Pb2+ could effectively inhibit the formation of zinc dendrites,and enhance the charging capacity of zinc electrode.It showed a high charging efficiency and effective inhibition to the growth of zinc dendrites when the charging was performed at a cathodic overpotential η=-200 mV in 0.05 g/L Pb2+ alkaline solution with the addition of 6-nitrobenzimidazole or benzimidazole.
The influences of 6-nitrobenzimidazole,benzimidazole and Pb2+ on zinc dendrite in KOH solution(4 mol/L) were investigated by means of current-time technique.The results showed that 6-nitrobenzimidazole,benzimidazole and Pb2+ could effectively inhibit the formation of zinc dendrites,and enhance the charging capacity of zinc electrode.It showed a high charging efficiency and effective inhibition to the growth of zinc dendrites when the charging was performed at a cathodic overpotential η=-200 mV in 0.05 g/L Pb2+ alkaline solution with the addition of 6-nitrobenzimidazole or benzimidazole.
2012, 29(3): 364-366
doi: 10.3724/SP.J.1095.2012.00205
Abstract:
A sensitive method was used to measure the content of styrene-butadiene rubber(SBR) in modified asphalt by HPLC.The temperature was set at 30℃ and a wavelength of 222 nm was used for the detector.A mobile phase of hexane,acetonitrile and THF with equal proportion was used.The RSD of this method is 1.5%,and a linear equation of y=800.94x+579.03 with a correlation coefficient of r=0.9998 was obtained.
A sensitive method was used to measure the content of styrene-butadiene rubber(SBR) in modified asphalt by HPLC.The temperature was set at 30℃ and a wavelength of 222 nm was used for the detector.A mobile phase of hexane,acetonitrile and THF with equal proportion was used.The RSD of this method is 1.5%,and a linear equation of y=800.94x+579.03 with a correlation coefficient of r=0.9998 was obtained.
