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2014 Volume 31 Issue 4
2014, 31(4): 367-376
doi: 10.3724/SP.J.1095.2014.30203
Abstract:
With the rapid increase in biodiesel production,the utilization of a large surplus glycerol as a byproduct from biodiesel manufacture has become an important topic.Glycerol is a green multifunctional "platform molecule".Products from the chemical transformation of glycerol through hydrogenolysis(reduction),oxidation,reforming(pyrolysis),dehydration,etherification and some compounds by reacting it with other reagents can replace those based on the petrochemical raw materials.The latest transformation progress of glycerol into other chemical products was reviewed in this article.
With the rapid increase in biodiesel production,the utilization of a large surplus glycerol as a byproduct from biodiesel manufacture has become an important topic.Glycerol is a green multifunctional "platform molecule".Products from the chemical transformation of glycerol through hydrogenolysis(reduction),oxidation,reforming(pyrolysis),dehydration,etherification and some compounds by reacting it with other reagents can replace those based on the petrochemical raw materials.The latest transformation progress of glycerol into other chemical products was reviewed in this article.
2014, 31(4): 377-388
doi: 10.3724/SP.J.1095.2014.30457
Abstract:
During the past ten years,the application of semiconductor nanocrystal material-quantum dots has displayed an increased tendency in scientific and industrial production fields,and a broad research is developed from materials science to biological applications.The application of quantum dots has substantially impacted on many research areas,such as biological imaging,phototherapy,drug/gene delivery,and solar cell.It is a key point to control the interactions between quantum dots and cell through adjusting surface properties of quantum dots.As the potential cytotoxicity of quantum dots arise,nanotoxicity becomes an important indicator of nanomaterials security assessment,and scientists pay more attention to the research of their potential toxicity.In this review we overviewed the properties of quantum dots,the applications in cell biology and the cytotoxicity research in biomedicine related field.Moreover,the future prospects for applications of quantum dots were briefly presented.
During the past ten years,the application of semiconductor nanocrystal material-quantum dots has displayed an increased tendency in scientific and industrial production fields,and a broad research is developed from materials science to biological applications.The application of quantum dots has substantially impacted on many research areas,such as biological imaging,phototherapy,drug/gene delivery,and solar cell.It is a key point to control the interactions between quantum dots and cell through adjusting surface properties of quantum dots.As the potential cytotoxicity of quantum dots arise,nanotoxicity becomes an important indicator of nanomaterials security assessment,and scientists pay more attention to the research of their potential toxicity.In this review we overviewed the properties of quantum dots,the applications in cell biology and the cytotoxicity research in biomedicine related field.Moreover,the future prospects for applications of quantum dots were briefly presented.
2014, 31(4): 389-393
doi: 10.3724/SP.J.1095.2014.30226
Abstract:
For the self-consistent field theory(SCFT) simulation of the phase diagrams of copolymer blends,the grand canonical ensemble and canonical ensemble need to be combined in the simulation.Through converting the variables between grand canonical ensemble and canonical ensemble,we can calculate the variables of grand canonical ensemble directly from canonical ensemble,which simplify the calculation.Here the method was applied to calculate the phase diagram of diblock copolymer(A-b-B)/homopolymer(A) blends with different molecular masses.It was found that the macrophase separation is prevented in the blends by increasing the volume fraction,fA of the block copolymer or decreasing the molecular mass of the homopolymer.
For the self-consistent field theory(SCFT) simulation of the phase diagrams of copolymer blends,the grand canonical ensemble and canonical ensemble need to be combined in the simulation.Through converting the variables between grand canonical ensemble and canonical ensemble,we can calculate the variables of grand canonical ensemble directly from canonical ensemble,which simplify the calculation.Here the method was applied to calculate the phase diagram of diblock copolymer(A-b-B)/homopolymer(A) blends with different molecular masses.It was found that the macrophase separation is prevented in the blends by increasing the volume fraction,fA of the block copolymer or decreasing the molecular mass of the homopolymer.
2014, 31(4): 394-399
doi: 10.3724/SP.J.1095.2014.30297
Abstract:
The change of activity of the SAPO-34 zeolite catalyst in the methanol to olefin process(MTO) was studied after the catalyst started to lose activity in the fixed-bed isothermal integral reactor.The effect of temperature,space speed and time on stream on the change of catalyst activity was investigated.The deactivation function showed a good agreement with the experimental data.By analyzing the deactivation function,the relations between time when the deactivation speed was fast and both temperature and space velocity were obtained.The deactivation process obeyed the deactivation mechanism on the inhomogeneous surface.After the SAPO-34 zeolite started to lose activity,the effect of deactivation time was greater than the effect of space speed and reaction temperature.
The change of activity of the SAPO-34 zeolite catalyst in the methanol to olefin process(MTO) was studied after the catalyst started to lose activity in the fixed-bed isothermal integral reactor.The effect of temperature,space speed and time on stream on the change of catalyst activity was investigated.The deactivation function showed a good agreement with the experimental data.By analyzing the deactivation function,the relations between time when the deactivation speed was fast and both temperature and space velocity were obtained.The deactivation process obeyed the deactivation mechanism on the inhomogeneous surface.After the SAPO-34 zeolite started to lose activity,the effect of deactivation time was greater than the effect of space speed and reaction temperature.
2014, 31(4): 400-405
doi: 10.3724/SP.J.1095.2014.30338
Abstract:
A series of Y-Mg-Al-F catalysts was prepared by the deposition-precipitation method,and characterized by X-ray diffraction(XRD),NH3-TPD(temperature-programmed desorption) and Raman spectroscopy.The catalysts were used in catalytic pyrolysis of 1,1,1,2-tetrafluoroethane(HFC-134a) to trifluoroethylene(TrFE).Their catalytic performances were compared with AlF3 catalyst.The results show that the Y-Mg-Al-F catalyst calcined at 1100℃ exhibits higher activity and stability than others.The conversion of HFC-134a is higher than 25% at a reaction temperature of 400℃.The surface acidity and carbon deposits on the catalyst surface have main effects on the catalytic activity and stability of catalysts.
A series of Y-Mg-Al-F catalysts was prepared by the deposition-precipitation method,and characterized by X-ray diffraction(XRD),NH3-TPD(temperature-programmed desorption) and Raman spectroscopy.The catalysts were used in catalytic pyrolysis of 1,1,1,2-tetrafluoroethane(HFC-134a) to trifluoroethylene(TrFE).Their catalytic performances were compared with AlF3 catalyst.The results show that the Y-Mg-Al-F catalyst calcined at 1100℃ exhibits higher activity and stability than others.The conversion of HFC-134a is higher than 25% at a reaction temperature of 400℃.The surface acidity and carbon deposits on the catalyst surface have main effects on the catalytic activity and stability of catalysts.
2014, 31(4): 406-410
doi: 10.3724/SP.J.1095.2014.30305
Abstract:
CMK-3-IL heterogeneous catalysts were synthesized using ordered mesoporous carbons CMK-3 as the support to immobilize imidazoles ionic liquids and applied to the synthesis of cyclic carbonate.The catalyst samples were characterized by X-ray powder diffraction(XRD),nitrogen adsorption-desorption,transmission electron microscopy(TEM),thermogravimetric analysis(TGA) and elemental analysis.The results show that the ionic liquids are grafted on the surface of the CMK-3 and the resultant hybrid materials retains mesoporous structure after immobilization.The nitrogen adsorption results indicate that pore volume,pore diameter and surface area of CMK-3-IL are slightly reduced.CMK-3-IL shows much higher catalytic activity.A 64% conversion of propylene oxide and a 99% selectivity of propylene carbonate can be achieved when the catalytic reaction is carried out at 120℃ under 2 MPa for 6 h.
CMK-3-IL heterogeneous catalysts were synthesized using ordered mesoporous carbons CMK-3 as the support to immobilize imidazoles ionic liquids and applied to the synthesis of cyclic carbonate.The catalyst samples were characterized by X-ray powder diffraction(XRD),nitrogen adsorption-desorption,transmission electron microscopy(TEM),thermogravimetric analysis(TGA) and elemental analysis.The results show that the ionic liquids are grafted on the surface of the CMK-3 and the resultant hybrid materials retains mesoporous structure after immobilization.The nitrogen adsorption results indicate that pore volume,pore diameter and surface area of CMK-3-IL are slightly reduced.CMK-3-IL shows much higher catalytic activity.A 64% conversion of propylene oxide and a 99% selectivity of propylene carbonate can be achieved when the catalytic reaction is carried out at 120℃ under 2 MPa for 6 h.
2014, 31(4): 411-416
doi: 10.3724/SP.J.1095.2014.30284
Abstract:
A new copper acetate complex derived from C2-symmetric diamine,which can be easily prepared from L-proline,was developed and used as an efficient catalyst in Henry reaction between various aldehydes and nitroalkanes.The results demonstrate that the reaction temperature,solvents and catalyst loadings have considerably effects on both yields and reaction rates.The yields are 60%~92% in optimal reaction conditions:at room temperature,ethanol as solvent,10% molar fraction of catalyst loading.All aldehydes react efficiently with tested nitroalkanes to produce corresponding β-nitroalcohols.When aromatic aldehydes react with nitroethane,excellent diastereoselectivity can be obtained.However,diastereoselectivity is modest in the reaction of aliphatic acetaldehyde.
A new copper acetate complex derived from C2-symmetric diamine,which can be easily prepared from L-proline,was developed and used as an efficient catalyst in Henry reaction between various aldehydes and nitroalkanes.The results demonstrate that the reaction temperature,solvents and catalyst loadings have considerably effects on both yields and reaction rates.The yields are 60%~92% in optimal reaction conditions:at room temperature,ethanol as solvent,10% molar fraction of catalyst loading.All aldehydes react efficiently with tested nitroalkanes to produce corresponding β-nitroalcohols.When aromatic aldehydes react with nitroethane,excellent diastereoselectivity can be obtained.However,diastereoselectivity is modest in the reaction of aliphatic acetaldehyde.
2014, 31(4): 417-423
doi: 10.3724/SP.J.1095.2014.30264
Abstract:
An axial imidazole five-coordinate biomimetic catalyst was prepared from natural hemin and imidazole,and was immobilized on the surface of magnetic cellulose nanospheres.These modified nanospheres were characterized by UV-visible(UV-Vis) spectrophotometer,Fourier transform infrared spectroscopy(FT-IR),transmission electron microscopy(TEM),thermal gravimetric analysis(TGA) and vibrating sample magnetometry(VSM).Their photocatalytic activity and stability were evaluated by the catalytic degradation of hydroquinone under visible light irradiation.The results show that 96.97% of HQ was degraded with an initial concentration of HQ at 20 mg/L under simulated sunlight irradiation for 6 h at pH=6 in the presence the catalyst at 0.2 g/L.After five-recycle,the photocatalyst still provides up to 92% degradation of HQ.The photocatalytic degradation mechanism of HQ under visible light irradiation was also investigated.
An axial imidazole five-coordinate biomimetic catalyst was prepared from natural hemin and imidazole,and was immobilized on the surface of magnetic cellulose nanospheres.These modified nanospheres were characterized by UV-visible(UV-Vis) spectrophotometer,Fourier transform infrared spectroscopy(FT-IR),transmission electron microscopy(TEM),thermal gravimetric analysis(TGA) and vibrating sample magnetometry(VSM).Their photocatalytic activity and stability were evaluated by the catalytic degradation of hydroquinone under visible light irradiation.The results show that 96.97% of HQ was degraded with an initial concentration of HQ at 20 mg/L under simulated sunlight irradiation for 6 h at pH=6 in the presence the catalyst at 0.2 g/L.After five-recycle,the photocatalyst still provides up to 92% degradation of HQ.The photocatalytic degradation mechanism of HQ under visible light irradiation was also investigated.
2014, 31(4): 424-430
doi: 10.3724/SP.J.1095.2014.30316
Abstract:
Conversion of fructose into 5-hydroxymethylfurfural(HMF) was investigated in various acidic ionic liquids as catalyst and solvent.The acidic ionic liquids include SO3H-functionalized ionic liquids,imidazolebased ionic liquids and pyridine-based acid ionic liquids.The catalysts were characterized by NMR and IR.The Hammett acidity function was obatined by UV-Vis measurements with an Hammett indicator.The acid strength was compared.The results show that the acid strength of catalysts affects the reaction.Ionic liquid has a high activity without the addition of other catalyst and solvent.When 1-butyl-3-methylimidazolium chloride(BmimCl) was used as the catalyst,the yield of HMF was 74.97% within 4 h at 120℃.
Conversion of fructose into 5-hydroxymethylfurfural(HMF) was investigated in various acidic ionic liquids as catalyst and solvent.The acidic ionic liquids include SO3H-functionalized ionic liquids,imidazolebased ionic liquids and pyridine-based acid ionic liquids.The catalysts were characterized by NMR and IR.The Hammett acidity function was obatined by UV-Vis measurements with an Hammett indicator.The acid strength was compared.The results show that the acid strength of catalysts affects the reaction.Ionic liquid has a high activity without the addition of other catalyst and solvent.When 1-butyl-3-methylimidazolium chloride(BmimCl) was used as the catalyst,the yield of HMF was 74.97% within 4 h at 120℃.
2014, 31(4): 431-436
doi: 10.3724/SP.J.1095.2014.30339
Abstract:
A series of ionic liquids was synthesized from phosphotungstic acid and alkyl substituted quaternary phosphonium salts with different molar ratios,and characterized by DSC and IR.The results show that[P(C14H29)(C6H13)3]-phosphotungstic series ionic liquids are liquid at room temperature.The degradation of Rhodamine-B(RhB) dye was successfully achieved by different phosphotungstic quaternary phosphonium ionic liquids under visible light irradiation.The degradation efficiency was characterized by decolorization and chemical oxygen demand(COD) of RhB.The influence of experimental parameters,such as the carbon chain length in the phosphonium ionic liquid,dosage of catalysts,irradiation time and the concentration of RhB solution on photo-catalyzed degradation of RhB were investigated.The results indicate that[P(C14H29)(C6H13)3]3-[PW12O40]ionic liquid shows the best photo-catalytic degradation effect under visible light irradiation.The degradation rate can be up to 95% when the catalyst dosage is 0.3 g and the concentration of RhB is 8.35×10-5 mol/L(50 mL) in 3 h.The decolorization of[P(C14H29)(C6H13)3]3-PW12O40 can reach 97% even used for 5 times.
A series of ionic liquids was synthesized from phosphotungstic acid and alkyl substituted quaternary phosphonium salts with different molar ratios,and characterized by DSC and IR.The results show that[P(C14H29)(C6H13)3]-phosphotungstic series ionic liquids are liquid at room temperature.The degradation of Rhodamine-B(RhB) dye was successfully achieved by different phosphotungstic quaternary phosphonium ionic liquids under visible light irradiation.The degradation efficiency was characterized by decolorization and chemical oxygen demand(COD) of RhB.The influence of experimental parameters,such as the carbon chain length in the phosphonium ionic liquid,dosage of catalysts,irradiation time and the concentration of RhB solution on photo-catalyzed degradation of RhB were investigated.The results indicate that[P(C14H29)(C6H13)3]3-[PW12O40]ionic liquid shows the best photo-catalytic degradation effect under visible light irradiation.The degradation rate can be up to 95% when the catalyst dosage is 0.3 g and the concentration of RhB is 8.35×10-5 mol/L(50 mL) in 3 h.The decolorization of[P(C14H29)(C6H13)3]3-PW12O40 can reach 97% even used for 5 times.
2014, 31(4): 437-443
doi: 10.3724/SP.J.1095.2014.30261
Abstract:
To establish a clean and efficient nitration process of phenolic compounds,heteropolyacid H6PMo9V3O40(PMAV3) and chromatographic silica gel were respectively chosen as active component and carrier for the preparation of a series of supported catalysts(PMAV3/SiO2) via the conventional impregnation method.The catalysts were characterized by Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),N2 adsorption-desorption and thermogravimetry-differential scanning calorimetry(TG-DSC).The catalytic performance of catalysts was evaluated for the nitration of phenols.The results reveals that PMAV3/SiO2 exhibits excellent catalytic activity and regioselectivity for the nitration of phenols,the nitration yield is in the range of 83.7%~94.5%.For salicylic acid,the para-selectivity is nearly 100%,but for phenol,2-methylphenol,2-chlorophenol and 2-fluorphenol,the ortho-selectivity is observed.The textural properties of PMAV 3/SiO2 are close to that of PMAV3,but BET of the supported catalysts is decreased with the rise of PMAV 3 loading.PMAV3/SiO2 shows better thermal stability than PMAV3.The catalyst can be recovered easily and reused for five times without noticeable drop in activity.
To establish a clean and efficient nitration process of phenolic compounds,heteropolyacid H6PMo9V3O40(PMAV3) and chromatographic silica gel were respectively chosen as active component and carrier for the preparation of a series of supported catalysts(PMAV3/SiO2) via the conventional impregnation method.The catalysts were characterized by Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),N2 adsorption-desorption and thermogravimetry-differential scanning calorimetry(TG-DSC).The catalytic performance of catalysts was evaluated for the nitration of phenols.The results reveals that PMAV3/SiO2 exhibits excellent catalytic activity and regioselectivity for the nitration of phenols,the nitration yield is in the range of 83.7%~94.5%.For salicylic acid,the para-selectivity is nearly 100%,but for phenol,2-methylphenol,2-chlorophenol and 2-fluorphenol,the ortho-selectivity is observed.The textural properties of PMAV 3/SiO2 are close to that of PMAV3,but BET of the supported catalysts is decreased with the rise of PMAV 3 loading.PMAV3/SiO2 shows better thermal stability than PMAV3.The catalyst can be recovered easily and reused for five times without noticeable drop in activity.
2014, 31(4): 444-449
doi: 10.3724/SP.J.1095.2014.30299
Abstract:
An analytical method was established for the simultaneous determination of glucuronic acid and glucuronolactone using ion-exclusion chromatography.The separation was performed on a Boston HC-B75 H+ column at 25℃ by HPLC equipped with an ultraviolet detector at the wavelength of 220 nm.The mobile phase is 5 mmol/L sulfuric acid with a flow rate of 0.6 mL/min.The quantification was performed by an external standard.The linear ranges for glucuronic acid and glucuronolactone are 10~1200 mg/L and 5~600 mg/L(r >0.9999),respectively.The detection and quantification limits for the two compounds are 0.1 mg/L and 0.3 mg/L,respectively.The standard deviations for glucuronic acid and glucuronolactone are 1.00% and 0.35%,respectively.The recovery ratios for glucuronic acid and glucuronolactone are 99.69% and 98.21%,respectively.This method is convenient,rapid,sensitive and suitable for the simultaneous determination of glucuronic acid and glucuronolactone.Temperature,pH and solvent affected the stability of glucuronic acid.
An analytical method was established for the simultaneous determination of glucuronic acid and glucuronolactone using ion-exclusion chromatography.The separation was performed on a Boston HC-B75 H+ column at 25℃ by HPLC equipped with an ultraviolet detector at the wavelength of 220 nm.The mobile phase is 5 mmol/L sulfuric acid with a flow rate of 0.6 mL/min.The quantification was performed by an external standard.The linear ranges for glucuronic acid and glucuronolactone are 10~1200 mg/L and 5~600 mg/L(r >0.9999),respectively.The detection and quantification limits for the two compounds are 0.1 mg/L and 0.3 mg/L,respectively.The standard deviations for glucuronic acid and glucuronolactone are 1.00% and 0.35%,respectively.The recovery ratios for glucuronic acid and glucuronolactone are 99.69% and 98.21%,respectively.This method is convenient,rapid,sensitive and suitable for the simultaneous determination of glucuronic acid and glucuronolactone.Temperature,pH and solvent affected the stability of glucuronic acid.
2014, 31(4): 450-454
doi: 10.3724/SP.J.1095.2014.30294
Abstract:
Ferrocenyl-1,3,4-triazoles Schiff base derivatives(5a~5e) were synthesized and characterized by IR,1H NMR and HRMS for the first time.The cell division activity and auxin activity were tested by cucumber cotyledon method and wheat malt sheath method.At a concentration of 10 mol/L,four compounds show 46.9%~73.6% promoting activity which is higher than that of the control.The auxin activity of compound 5c is up to 25%.The herbicidal activities of the compounds are up to 68%~72%.Cyclic voltammetry was used to detect the electrochemical behavior of the target compounds using glassy carbon electrode modified with graphene in the Britton-Robison buffer solution.The influence of pH,potential scanning rate and concentration on the electrochemical behavior of the target compounds was studied.These compounds perform good redox reversibility when pH value is equal to 2 or 3.The logarithm of oxidation peak current(Ipc) shows good linear relationship with the logarithm of scanning rate and the logarithm of concentration.The electron transfer of compounds(5a~5d) is reversible process under control of adsorption-diffusion.The lowest of detection is 10-5 mol/L.
Ferrocenyl-1,3,4-triazoles Schiff base derivatives(5a~5e) were synthesized and characterized by IR,1H NMR and HRMS for the first time.The cell division activity and auxin activity were tested by cucumber cotyledon method and wheat malt sheath method.At a concentration of 10 mol/L,four compounds show 46.9%~73.6% promoting activity which is higher than that of the control.The auxin activity of compound 5c is up to 25%.The herbicidal activities of the compounds are up to 68%~72%.Cyclic voltammetry was used to detect the electrochemical behavior of the target compounds using glassy carbon electrode modified with graphene in the Britton-Robison buffer solution.The influence of pH,potential scanning rate and concentration on the electrochemical behavior of the target compounds was studied.These compounds perform good redox reversibility when pH value is equal to 2 or 3.The logarithm of oxidation peak current(Ipc) shows good linear relationship with the logarithm of scanning rate and the logarithm of concentration.The electron transfer of compounds(5a~5d) is reversible process under control of adsorption-diffusion.The lowest of detection is 10-5 mol/L.
2014, 31(4): 455-461
doi: 10.3724/SP.J.1095.2014.30270
Abstract:
A series of cathode materials Li(Ni1/3Co1/3Mn1/3)1-xAlxO2(0≤ x≤ 0.1) was synthesized by chemical method.The microstructure,surface morphology and electrochemical performance of products synthesized were characterized by X-ray diffraction,scanning electron microscopy and electrochemical techniques.The influence of different mixed Al content on the properties of ceramic materials was studied.The results indicat that the as-prepared Li(Ni1/3Co1/3Mn1/3)1-xAlxO2 has a hexagonal α-NaFeO2 structure with a space group of R3m and hexagonal system.Initial discharge capacity of Li(Ni1/3Co1/3Mn1/3)0.95Al0.05O2 is 166.30 mA·h/g in the voltage window of 2.5~4.5 V and shows only 4.43% reduction after 60 cycles.AC impedance method was adopted to study the electrochemical circulation mechanism of Li(Ni1/3Co1/3Mn1/3)O2 and Li(Ni1/3Co1/3Mn1/3)0.95Al0.05O2,and Al-coped cathode material is suitable for high rate discharging.
A series of cathode materials Li(Ni1/3Co1/3Mn1/3)1-xAlxO2(0≤ x≤ 0.1) was synthesized by chemical method.The microstructure,surface morphology and electrochemical performance of products synthesized were characterized by X-ray diffraction,scanning electron microscopy and electrochemical techniques.The influence of different mixed Al content on the properties of ceramic materials was studied.The results indicat that the as-prepared Li(Ni1/3Co1/3Mn1/3)1-xAlxO2 has a hexagonal α-NaFeO2 structure with a space group of R3m and hexagonal system.Initial discharge capacity of Li(Ni1/3Co1/3Mn1/3)0.95Al0.05O2 is 166.30 mA·h/g in the voltage window of 2.5~4.5 V and shows only 4.43% reduction after 60 cycles.AC impedance method was adopted to study the electrochemical circulation mechanism of Li(Ni1/3Co1/3Mn1/3)O2 and Li(Ni1/3Co1/3Mn1/3)0.95Al0.05O2,and Al-coped cathode material is suitable for high rate discharging.
2014, 31(4): 462-468
doi: 10.3724/SP.J.1095.2014.30330
Abstract:
The corrosion inhibition effect of the Bohea leaves exctrative on carbon steel in 1.0 mol/L HCl solution was investigated by using potentiodynamic polarization and electrochemical impedance spectroscopy.The results indicate that the Bohea leaves extractive exhibits good corrosion inhibition effect on carbon steel.The inhibition efficiency increased with increasing concentration of Bohea leaves extractive.The Bohea leaves extractive is a mixed-type inhibitor.The adsorption of the effective corrosion inhibition component of Bohea leaves extractive on the carbon steel surface conforms with Langmuir adsorption isotherm equation,which belongs to monolayer adsorption.
The corrosion inhibition effect of the Bohea leaves exctrative on carbon steel in 1.0 mol/L HCl solution was investigated by using potentiodynamic polarization and electrochemical impedance spectroscopy.The results indicate that the Bohea leaves extractive exhibits good corrosion inhibition effect on carbon steel.The inhibition efficiency increased with increasing concentration of Bohea leaves extractive.The Bohea leaves extractive is a mixed-type inhibitor.The adsorption of the effective corrosion inhibition component of Bohea leaves extractive on the carbon steel surface conforms with Langmuir adsorption isotherm equation,which belongs to monolayer adsorption.
2014, 31(4): 469-473
doi: 10.3724/SP.J.1095.2014.30326
Abstract:
Mono-6-deoxy-6-imidazole-β-cyclodextrin polymer(β-CDIMCP) was synthesized and used as a new solid phase adsorbent to pre-concentrate/separate trace amount of safranine T in solutions.The results from UV-visible spectroscopy measurements show that β-CDIMCP had a better adsorption performance than β-CDCP.Safranine T was adsorbed by β-CDIMCP rapidly with an adsorption efficiency of 95% at room temperature and pH=11.0.When 3.0 mL of anhydrous ethanol was used as the eluant,the elution efficiency reached 90% in 8 minutes.Under the optimum condition,the preconcentration factor of the proposed method was 10.The detection limit(DL),RSD,linear range,and correlation coefficient was found to be 4.9 μg/L,3.4%(n=3,ρ=3.00 mg/L),0.09~6.0 mg/L and 0.9972,respectively.This proposed method was successfully applied to the determination of safranine T in real samples.The molecular interaction between β-CDIMCP and safranine T was studied through the inclusion constant study.
Mono-6-deoxy-6-imidazole-β-cyclodextrin polymer(β-CDIMCP) was synthesized and used as a new solid phase adsorbent to pre-concentrate/separate trace amount of safranine T in solutions.The results from UV-visible spectroscopy measurements show that β-CDIMCP had a better adsorption performance than β-CDCP.Safranine T was adsorbed by β-CDIMCP rapidly with an adsorption efficiency of 95% at room temperature and pH=11.0.When 3.0 mL of anhydrous ethanol was used as the eluant,the elution efficiency reached 90% in 8 minutes.Under the optimum condition,the preconcentration factor of the proposed method was 10.The detection limit(DL),RSD,linear range,and correlation coefficient was found to be 4.9 μg/L,3.4%(n=3,ρ=3.00 mg/L),0.09~6.0 mg/L and 0.9972,respectively.This proposed method was successfully applied to the determination of safranine T in real samples.The molecular interaction between β-CDIMCP and safranine T was studied through the inclusion constant study.
2014, 31(4): 474-481
doi: 10.3724/SP.J.1095.2014.30328
Abstract:
A new method for rational design of molecularly imprinted polymer(MIP) of 4-nitrophenol(4-NP) was established.Using the method,nonimprinted polymer(NIP) library screening,vinylimidazole was selected as the best functional monomer.Acetonitrile and trimethylolpropane trimethacrylate(TRIM) were the best polymerization solvent and crosslinker,respectively.Through the optimization of the solid phase extraction(SPE) profile,the best imprinting effect was achieved in pH=2.5 phosphate buffer,washing with the buffer containing 45% acetonitrile and eluting with methanol.The maximum adsorption capacity of the polymer was 5.8 mg/g.Extraction recoveries of imprinted polymers for 4-NP and its analogs,phenol and 4-chlorophenol,were found to be 96.0%,78.8% and 77.8%,respectively,proving its high selectivity.It was also successfully used for SPE of 4-NP from spiked tap water with a recovery of 93.1%.The method is proved to be effective and fast for the preparation of MIPs.
A new method for rational design of molecularly imprinted polymer(MIP) of 4-nitrophenol(4-NP) was established.Using the method,nonimprinted polymer(NIP) library screening,vinylimidazole was selected as the best functional monomer.Acetonitrile and trimethylolpropane trimethacrylate(TRIM) were the best polymerization solvent and crosslinker,respectively.Through the optimization of the solid phase extraction(SPE) profile,the best imprinting effect was achieved in pH=2.5 phosphate buffer,washing with the buffer containing 45% acetonitrile and eluting with methanol.The maximum adsorption capacity of the polymer was 5.8 mg/g.Extraction recoveries of imprinted polymers for 4-NP and its analogs,phenol and 4-chlorophenol,were found to be 96.0%,78.8% and 77.8%,respectively,proving its high selectivity.It was also successfully used for SPE of 4-NP from spiked tap water with a recovery of 93.1%.The method is proved to be effective and fast for the preparation of MIPs.
2014, 31(4): 482-488
doi: 10.3724/SP.J.1095.2014.30336
Abstract:
A simple and rapid method based on QuEChERS(quick,easy,cheap,effective,rugged and safe)-HPLC technology for the determination of acrylamide(AAM) in fried food was developed.The advantage of this method lies in that the pure water is used directly to eliminate the interference of sample base without introducing organic solvents in the modified QuEChERS method.With this method,AAM in samples was extracted with pure water using ultrasonic bath and cleaned up by primary secondary diamine(PSA).To determine the content of AAM,a C18 column with water-acetonitrile(V/V=1:99) as eluent and a UV detector adjusted at 208 nm were employed in HPLC.Under the optimal experiment conditions,there is a good linear relationship(r=0.9994) in the concentration range of 0.020~0.800 μg/g and the detection limit of AAM is 0.005 μg/g.The recoveries of AAM in samples are in the range of 83.96%~89.43%,with relative standard deviations(RSD) of 2.13%~5.87%.The developed method is proved to be simple,reliable and sensitive for fast determination of AAM in fried food such as instant noodles.
A simple and rapid method based on QuEChERS(quick,easy,cheap,effective,rugged and safe)-HPLC technology for the determination of acrylamide(AAM) in fried food was developed.The advantage of this method lies in that the pure water is used directly to eliminate the interference of sample base without introducing organic solvents in the modified QuEChERS method.With this method,AAM in samples was extracted with pure water using ultrasonic bath and cleaned up by primary secondary diamine(PSA).To determine the content of AAM,a C18 column with water-acetonitrile(V/V=1:99) as eluent and a UV detector adjusted at 208 nm were employed in HPLC.Under the optimal experiment conditions,there is a good linear relationship(r=0.9994) in the concentration range of 0.020~0.800 μg/g and the detection limit of AAM is 0.005 μg/g.The recoveries of AAM in samples are in the range of 83.96%~89.43%,with relative standard deviations(RSD) of 2.13%~5.87%.The developed method is proved to be simple,reliable and sensitive for fast determination of AAM in fried food such as instant noodles.
2014, 31(4): 489-495
doi: 10.3724/SP.J.1095.2014.30249
Abstract:
A simple and rapid colorimetric method was developed for the detection of melamine using 2-thiobarbituric acid-modified gold nanoparticles(TBA-AuNPs) as probes.Melamine can induce the aggregation of TBA-AuNPs via the hydrogen-bonding interactions in acetic acid buffer solutions(pH=7),resulting in the color change from wine-red to blue within 15 min at room temperature.Under optimized conditions,the absorption ratio of the A660/A520 shows good linear relationship with the melamine concentration in the range of 0.062~0.18 μmol/L and 0.18~6.0 μmol/L,respectively,with the detection limit of 0.043 μmol/L.The recoveries of the method are within the range of 102.8%~105.3%.It provides a platform for rapid,selective and sensitive colorimetric detection of melamine in milk samples.
A simple and rapid colorimetric method was developed for the detection of melamine using 2-thiobarbituric acid-modified gold nanoparticles(TBA-AuNPs) as probes.Melamine can induce the aggregation of TBA-AuNPs via the hydrogen-bonding interactions in acetic acid buffer solutions(pH=7),resulting in the color change from wine-red to blue within 15 min at room temperature.Under optimized conditions,the absorption ratio of the A660/A520 shows good linear relationship with the melamine concentration in the range of 0.062~0.18 μmol/L and 0.18~6.0 μmol/L,respectively,with the detection limit of 0.043 μmol/L.The recoveries of the method are within the range of 102.8%~105.3%.It provides a platform for rapid,selective and sensitive colorimetric detection of melamine in milk samples.
2014, 31(4): 496-501
doi: 10.3724/SP.J.1095.2014.30288
Abstract:
Paper is an ideal substrate material for low-cost diagnostic devices and shows a great potential in the fabrication of microfluidic paper-based analytical devices(μPADs).As one of the hot research fileds,a variety of materials and techniques have been proposed to fabricate μPADs.In this paper,we introduced a cheap,simpler and faster fabrication procedure,in which paraffin-heptane solution was used,toward this target.It is confirmed that as-developed protocol could be used for the simultaneous diagnostics of protein,glucose and pH.In addition,it is also applicable for quantitative analysis.The detection ranges of fabricated μPAD for bovine serum albumin and glucose were 2.0×10-5~1.00×10-4 mol/L and 0.02~0.1 mol/L,respectively.This paper also preliminarily studied the spreading phenomena of microfluidic channel barrier during heating treatment.We found that the thickness of barrier followed a linear discipline.
Paper is an ideal substrate material for low-cost diagnostic devices and shows a great potential in the fabrication of microfluidic paper-based analytical devices(μPADs).As one of the hot research fileds,a variety of materials and techniques have been proposed to fabricate μPADs.In this paper,we introduced a cheap,simpler and faster fabrication procedure,in which paraffin-heptane solution was used,toward this target.It is confirmed that as-developed protocol could be used for the simultaneous diagnostics of protein,glucose and pH.In addition,it is also applicable for quantitative analysis.The detection ranges of fabricated μPAD for bovine serum albumin and glucose were 2.0×10-5~1.00×10-4 mol/L and 0.02~0.1 mol/L,respectively.This paper also preliminarily studied the spreading phenomena of microfluidic channel barrier during heating treatment.We found that the thickness of barrier followed a linear discipline.
2014, 31(4): 502-504
doi: 10.3724/SP.J.1095.2014.30311
Abstract:
Reduced graphene oxide(RGO) was prepared by reducing graphene oxide(GO) with ethylenediamine(EDA).The RGO was characterized by Fourier transform infrared spectroscopy(FT-IR),Raman spectroscopy(Raman),thermogravimetric analysis(TGA),and scanning electron microscopy(SEM).The adsorption behaviors of the RGO toward Pb(Ⅱ),Cd(Ⅱ),Cu(Ⅱ) and Mn(Ⅱ) were studied.The adsorption capacities of RGO are found to be 396.6,115.3,54.2 and 38.6 mg/g for Pb(Ⅱ),Cd(Ⅱ),Cu(Ⅱ) and Mn(Ⅱ),respectively.The adsorbed Pb(Ⅱ) on the RGO can be desorbed in 0.05 mol/L HCl solution.After three cycles of adsorption and desorption,the adsorption capacity of RGO toward Pb(Ⅱ) can remain above 85% of the first adsorption amount.
Reduced graphene oxide(RGO) was prepared by reducing graphene oxide(GO) with ethylenediamine(EDA).The RGO was characterized by Fourier transform infrared spectroscopy(FT-IR),Raman spectroscopy(Raman),thermogravimetric analysis(TGA),and scanning electron microscopy(SEM).The adsorption behaviors of the RGO toward Pb(Ⅱ),Cd(Ⅱ),Cu(Ⅱ) and Mn(Ⅱ) were studied.The adsorption capacities of RGO are found to be 396.6,115.3,54.2 and 38.6 mg/g for Pb(Ⅱ),Cd(Ⅱ),Cu(Ⅱ) and Mn(Ⅱ),respectively.The adsorbed Pb(Ⅱ) on the RGO can be desorbed in 0.05 mol/L HCl solution.After three cycles of adsorption and desorption,the adsorption capacity of RGO toward Pb(Ⅱ) can remain above 85% of the first adsorption amount.
