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2014 Volume 31 Issue 1
2014, 31(1): 1-10
doi: 10.3724/SP.J.1095.2014.30074
Abstract:
Porphyrins are an important large class of macro-cyclic compounds,and exist extensively in nature and living bodies.The unique chemical structure of porphyrins endows them with superior physical,chemical and optical properties that make them to have broad applications in many fields.However,free porphyrins have intrinsic limitations,e.g.,poor chemical stability,ir-reusability,processing difficulty and so on.These limitations hinder their applications greatly.The natural porphyrins usually coexisted with some specific natural macromolecules.Under certain conditions,porphyrins could fully exert their functions.Accordingly,many suitable materials have been developed to immobilize porphyrins and metalloporphyrins in order to overcome the defects of free porphyrins described above and expand their applications.In this review,the common carriers of porphyrins,the usual methods for immobilizing porphyrins,and the latest application of immobilized porphyrin compounds in catalysis,sensor,and so on have been summarized.The application prospectives of immobilized porphyrins is also presented.
Porphyrins are an important large class of macro-cyclic compounds,and exist extensively in nature and living bodies.The unique chemical structure of porphyrins endows them with superior physical,chemical and optical properties that make them to have broad applications in many fields.However,free porphyrins have intrinsic limitations,e.g.,poor chemical stability,ir-reusability,processing difficulty and so on.These limitations hinder their applications greatly.The natural porphyrins usually coexisted with some specific natural macromolecules.Under certain conditions,porphyrins could fully exert their functions.Accordingly,many suitable materials have been developed to immobilize porphyrins and metalloporphyrins in order to overcome the defects of free porphyrins described above and expand their applications.In this review,the common carriers of porphyrins,the usual methods for immobilizing porphyrins,and the latest application of immobilized porphyrin compounds in catalysis,sensor,and so on have been summarized.The application prospectives of immobilized porphyrins is also presented.
2014, 31(1): 11-19
doi: 10.3724/SP.J.1095.2014.30116
Abstract:
Molecular beacon is an oligonucleotide probe of fluorescence.Molecular beacons are playing a very important role in molecular biology,genetics and molecular medicine because they have been shown to have very high selectivity,high sensitivity,and real-time detection capabilities.The structures and working mechanisms of a variety of novel molecular beacons have been outlined here.We briefly summarize the application of molecular beacon technology in the field of life sciences,and propose the prospect this technology.
Molecular beacon is an oligonucleotide probe of fluorescence.Molecular beacons are playing a very important role in molecular biology,genetics and molecular medicine because they have been shown to have very high selectivity,high sensitivity,and real-time detection capabilities.The structures and working mechanisms of a variety of novel molecular beacons have been outlined here.We briefly summarize the application of molecular beacon technology in the field of life sciences,and propose the prospect this technology.
2014, 31(1): 20-24
doi: 10.3724/SP.J.1095.2014.30152
Abstract:
In this work,we systematically studied the optoelectronic properties of four poly(3-butylthiophene)(P3BT) with different functional end-groups.The end-groups were found to be detrimental to the crystallization of P3BT.Nevertheless,the end-groups could modify the surface energy of P3BT and therefore achieve the tunable miscibility and film morphology of P3BT:PCBM blends.The solar cell devices based on these P3BTs with functional end-groups as donor materials have been fabricated and tested.We demonstrated that the allyl-terminated P3BT has relative higher crystallinity.And the appropriate miscibility of allylterminated P3BT and PCBM could lead to an ideal micro phase separation morphology of P3BT:PCBM in the active layer of solar cell device.The corresponding photovoltaic device performance could reach 3.1% which is 35% higher than that of conventional device using bromide-terminated P3BT.
In this work,we systematically studied the optoelectronic properties of four poly(3-butylthiophene)(P3BT) with different functional end-groups.The end-groups were found to be detrimental to the crystallization of P3BT.Nevertheless,the end-groups could modify the surface energy of P3BT and therefore achieve the tunable miscibility and film morphology of P3BT:PCBM blends.The solar cell devices based on these P3BTs with functional end-groups as donor materials have been fabricated and tested.We demonstrated that the allyl-terminated P3BT has relative higher crystallinity.And the appropriate miscibility of allylterminated P3BT and PCBM could lead to an ideal micro phase separation morphology of P3BT:PCBM in the active layer of solar cell device.The corresponding photovoltaic device performance could reach 3.1% which is 35% higher than that of conventional device using bromide-terminated P3BT.
2014, 31(1): 25-28
doi: 10.3724/SP.J.1095.2014.30100
Abstract:
Polyvinylidene fluoride(PVDF)/acrylic rubber(ACM) blends with controlled blend compositions and crystallization conditions exhibit nice shape memory properties.In this work,we systematically investigated the electrical and thermal conductivity of the PVDF/ACM shape memory alloy by the incorporation of multi-walled carbon nanotubes(CNT).It was found that the CNTs are homogeneously dispersed in the polymer matrix.The incorporation of CNTs significantly enhances both the electrical and thermal conductivity of the nanocomposites.The electrical conductivity of the nanocomposites with 4%(mass fraction) CNTs reaches 5000 Ω/square and the thermal conductivity is 0.157 W/(m·K) at 25℃.
Polyvinylidene fluoride(PVDF)/acrylic rubber(ACM) blends with controlled blend compositions and crystallization conditions exhibit nice shape memory properties.In this work,we systematically investigated the electrical and thermal conductivity of the PVDF/ACM shape memory alloy by the incorporation of multi-walled carbon nanotubes(CNT).It was found that the CNTs are homogeneously dispersed in the polymer matrix.The incorporation of CNTs significantly enhances both the electrical and thermal conductivity of the nanocomposites.The electrical conductivity of the nanocomposites with 4%(mass fraction) CNTs reaches 5000 Ω/square and the thermal conductivity is 0.157 W/(m·K) at 25℃.
2014, 31(1): 29-32
doi: 10.3724/SP.J.1095.2014.30122
Abstract:
The phase diagram of surface phase separation in poly(methyl methacrylate)/poly(styrene-coacrylonitrile)(PMMA/SAN) blend film with thickness of 130 nm was obtained by in-situ atomic force microscopy(AFM).The results show that the blend film has a lower critical system temperature(LCST) compared with the reported ex-situ phase diagram.The critical phase separation temperature was found to increase and the observed composition symmetry in ex-situ phase diagram was no longer existed.The difference between in-situ and ex-situ results can be ascribed to the thinner thickness of the film,different heat history and stronger substrate effect.
The phase diagram of surface phase separation in poly(methyl methacrylate)/poly(styrene-coacrylonitrile)(PMMA/SAN) blend film with thickness of 130 nm was obtained by in-situ atomic force microscopy(AFM).The results show that the blend film has a lower critical system temperature(LCST) compared with the reported ex-situ phase diagram.The critical phase separation temperature was found to increase and the observed composition symmetry in ex-situ phase diagram was no longer existed.The difference between in-situ and ex-situ results can be ascribed to the thinner thickness of the film,different heat history and stronger substrate effect.
2014, 31(1): 33-40
doi: 10.3724/SP.J.1095.2014.30080
Abstract:
Abstract A pair of diastereoisomeric aziridino alcohols which could be readily prepared from the reaction between(S)-α-methylbenzyl amine and methyl acrylate has been used as chiral ligands in zinc-catalyzed enantioselective Henry reaction between nitromethane and arylaldehydes.A moderate enantioselectivity of β-nitroalcohol,up to 64% ee value,could be achieved in this catalytic reaction.The possible transition states of the reaction were proposed.
Abstract A pair of diastereoisomeric aziridino alcohols which could be readily prepared from the reaction between(S)-α-methylbenzyl amine and methyl acrylate has been used as chiral ligands in zinc-catalyzed enantioselective Henry reaction between nitromethane and arylaldehydes.A moderate enantioselectivity of β-nitroalcohol,up to 64% ee value,could be achieved in this catalytic reaction.The possible transition states of the reaction were proposed.
2014, 31(1): 41-49
doi: 10.3724/SP.J.1095.2014.30043
Abstract:
A new catalytic system was applied to the oxidation reactions involved in the synthesis of 2,6-diamino-3,5-dinitropyrazine-1-oxide(LLM-105),in which protonated peroxotungstate immobilized into the network of cross-linked chitosan with the superparamagnetic Fe3O4 core(Fe3O4/CS/HWO) was used as the catalyst.With H2O2 as the oxidant,good to excellent yields could be achieved with pyrazine,2,6-dimethoxypyrazine,2,6-dichloropyrazine and 2-chloro-6-methoxypyrazine as the substrates without addition of trifluoracetic acid.A representative procedure for the oxidation process is as following:to 30 mL of CH3CN containing substrate(10 mmol) and Fe3O4/CS/HWO(0.1 mmol,about 0.1 g),30% H2O2(5 mL) was added dropwisely by 5 times at 60℃ temperature.The oxidation process was monitored by TLC.Product could be obtained with a yield ranging from 60% to 73%.Theoretical studies were also carried out with Gaussian 03 to evaluate the oxidation process.All of the calculated data matched well with the experimental results.
A new catalytic system was applied to the oxidation reactions involved in the synthesis of 2,6-diamino-3,5-dinitropyrazine-1-oxide(LLM-105),in which protonated peroxotungstate immobilized into the network of cross-linked chitosan with the superparamagnetic Fe3O4 core(Fe3O4/CS/HWO) was used as the catalyst.With H2O2 as the oxidant,good to excellent yields could be achieved with pyrazine,2,6-dimethoxypyrazine,2,6-dichloropyrazine and 2-chloro-6-methoxypyrazine as the substrates without addition of trifluoracetic acid.A representative procedure for the oxidation process is as following:to 30 mL of CH3CN containing substrate(10 mmol) and Fe3O4/CS/HWO(0.1 mmol,about 0.1 g),30% H2O2(5 mL) was added dropwisely by 5 times at 60℃ temperature.The oxidation process was monitored by TLC.Product could be obtained with a yield ranging from 60% to 73%.Theoretical studies were also carried out with Gaussian 03 to evaluate the oxidation process.All of the calculated data matched well with the experimental results.
2014, 31(1): 50-53
doi: 10.3724/SP.J.1095.2014.30007
Abstract:
An improved method for the preparation of N-toluenesulfonyl benzodiazepine-5-ketone,a key intermediate used for conivaptan hydrochloride synthesis,was developed.The starting materials are p-toluene sulfonyl chloride and methyl anthranilate,and the synthesis procedure includes amidation,imide and halogenated hydrocarbon condensation,Bechmmann cyclization,hydrolysis and decarboxylation,etc.In the synthesis process,the amount of the toxic solvent pyridine is reduced;sodium hydride,which is explosive in water,is replaced by potassium tert-butyl alcohol;and methyl tetrahydrofuran,which is commercially available and easily recovered,is used as the solvent instead of butanone.The total yield of the target compound increases from 55% to 63%,and the purity is 99% or more.The obtained compound was confirmed by the melting point measurement and 1H NMR spectroscopy.The yield of this intermediate and its quality have been significantly improved,and the yield of the conivaptan hydrochloride is thereby greatly increased.
An improved method for the preparation of N-toluenesulfonyl benzodiazepine-5-ketone,a key intermediate used for conivaptan hydrochloride synthesis,was developed.The starting materials are p-toluene sulfonyl chloride and methyl anthranilate,and the synthesis procedure includes amidation,imide and halogenated hydrocarbon condensation,Bechmmann cyclization,hydrolysis and decarboxylation,etc.In the synthesis process,the amount of the toxic solvent pyridine is reduced;sodium hydride,which is explosive in water,is replaced by potassium tert-butyl alcohol;and methyl tetrahydrofuran,which is commercially available and easily recovered,is used as the solvent instead of butanone.The total yield of the target compound increases from 55% to 63%,and the purity is 99% or more.The obtained compound was confirmed by the melting point measurement and 1H NMR spectroscopy.The yield of this intermediate and its quality have been significantly improved,and the yield of the conivaptan hydrochloride is thereby greatly increased.
2014, 31(1): 54-60
doi: 10.3724/SP.J.1095.2014.30101
Abstract:
The effect of pretreating biomass(bagasse/eucalyptus) with ionic liquids(ILs) EmimAc and AmimCl has been explored by assessing the saccharification yield.Factors including temperature,time and solid-to-liquid ratio have been investigated.The results indicate that two ILs produce the best results for the two kinds of biomass at 140℃ when the solid-to-liquid ratio is 1:15.For EmimAc,the optimum pretreatment time is 12 h for eucalyptus,and 4 h for bagasse,respectively.For AmimCl,the optimum pretreatment time is 14 h for eucalyptus,and 8 h for bagasse,respectively.The saccharification yields of EminAc pretreated eucalyptus and bagasse are 13.931 and 3.886 times those of traditional methods,respectively.For AmimCl,the saccharification yields ars imoroved to 4.665 and 2.835 times,respectively.The results show that EmimAc exhibits a better pretreatment effect than AmimCl.
The effect of pretreating biomass(bagasse/eucalyptus) with ionic liquids(ILs) EmimAc and AmimCl has been explored by assessing the saccharification yield.Factors including temperature,time and solid-to-liquid ratio have been investigated.The results indicate that two ILs produce the best results for the two kinds of biomass at 140℃ when the solid-to-liquid ratio is 1:15.For EmimAc,the optimum pretreatment time is 12 h for eucalyptus,and 4 h for bagasse,respectively.For AmimCl,the optimum pretreatment time is 14 h for eucalyptus,and 8 h for bagasse,respectively.The saccharification yields of EminAc pretreated eucalyptus and bagasse are 13.931 and 3.886 times those of traditional methods,respectively.For AmimCl,the saccharification yields ars imoroved to 4.665 and 2.835 times,respectively.The results show that EmimAc exhibits a better pretreatment effect than AmimCl.
2014, 31(1): 61-64
doi: 10.3724/SP.J.1095.2014.30051
Abstract:
Polyvinyl alcohol/chitosan/nano-hydroxyapatite(PVA/CS/n-HA) hydrogel was prepared via the chem-physical method.Effects of PVA content and the mass fraction of glutaraldehyde(GA) on the performance of the composite material were studied by testing its moisture content,tensile strength,infrared spectroscopy and TG spectrum.The results showed that when the mass ratio of PVA and CS+n-HA is 5:1,and the mass fraction of GA is 2%,the composite hydrogel material has an excellent integrated performance.The moisture content,tensile strength,and elongation breakage are 82.0%,2.14 MPa and 343.26%,respectively.Simultaneous thermal analysis(STA) results show that there is only water evaporation from 25℃ to 140℃,and the material starts to decompose at 360℃,suggesting that the material has a good thermal stability.Infrared analysis results show that there is a cross-linking reaction between CS and GA.
Polyvinyl alcohol/chitosan/nano-hydroxyapatite(PVA/CS/n-HA) hydrogel was prepared via the chem-physical method.Effects of PVA content and the mass fraction of glutaraldehyde(GA) on the performance of the composite material were studied by testing its moisture content,tensile strength,infrared spectroscopy and TG spectrum.The results showed that when the mass ratio of PVA and CS+n-HA is 5:1,and the mass fraction of GA is 2%,the composite hydrogel material has an excellent integrated performance.The moisture content,tensile strength,and elongation breakage are 82.0%,2.14 MPa and 343.26%,respectively.Simultaneous thermal analysis(STA) results show that there is only water evaporation from 25℃ to 140℃,and the material starts to decompose at 360℃,suggesting that the material has a good thermal stability.Infrared analysis results show that there is a cross-linking reaction between CS and GA.
2014, 31(1): 65-68
doi: 10.3724/SP.J.1095.2014.30064
Abstract:
The ultrafine zinc tungstate(ZnWO4) nanorod was synthesized in an aqueous solution containing cetyltrimethylammonium bromide(CTAB) using a hydrothermal method.The prepared samples were characterized by X-ray diffraction,scanning electron microscopy and UV-Visible diffuse reflectance spectroscopy.The resulting ZnWO4 sample was examined as photocatalyst for degradation of methyl orange in aqueous solutions under mercury lamp irradiation.The results show that the ZnWO4 nanorods are thin and long under the action of CTAB micelle.The photocatalytic activity of the ultrafine ZnWO4 nanorod is higher than that of the common ZnWO 4 nanorod.
The ultrafine zinc tungstate(ZnWO4) nanorod was synthesized in an aqueous solution containing cetyltrimethylammonium bromide(CTAB) using a hydrothermal method.The prepared samples were characterized by X-ray diffraction,scanning electron microscopy and UV-Visible diffuse reflectance spectroscopy.The resulting ZnWO4 sample was examined as photocatalyst for degradation of methyl orange in aqueous solutions under mercury lamp irradiation.The results show that the ZnWO4 nanorods are thin and long under the action of CTAB micelle.The photocatalytic activity of the ultrafine ZnWO4 nanorod is higher than that of the common ZnWO 4 nanorod.
2014, 31(1): 69-75
doi: 10.3724/SP.J.1095.2014.30257
Abstract:
Naphthalen-1-ylmethylphosphonic acid was modified on multiwall carbon nanotube(MWCNT) by the π-π stacking interaction.Then,the Pd catalyst was supported on it.Furthermore,the MWCNT supported Pd-Au(Pd-Au/MWCNT) catalyst was facially prepared by the replacement reaction between Pd nanoparticles and HAuCl4.Transmission electron microscopy,X-ray diffraction and X-ray photoelectron spectroscopy measurements showed that non-alloyed Pd-Au nanoparticles were highly dispersed on the surface of MWCNT.Cyclic voltammetry and chronoamperometric measurements indicated that the Pd-Au/MWCNT catalyst exhibited better electrocatalytic activity and stability for formic acid oxidation than that of the Pd/MWCNT catalyst.
Naphthalen-1-ylmethylphosphonic acid was modified on multiwall carbon nanotube(MWCNT) by the π-π stacking interaction.Then,the Pd catalyst was supported on it.Furthermore,the MWCNT supported Pd-Au(Pd-Au/MWCNT) catalyst was facially prepared by the replacement reaction between Pd nanoparticles and HAuCl4.Transmission electron microscopy,X-ray diffraction and X-ray photoelectron spectroscopy measurements showed that non-alloyed Pd-Au nanoparticles were highly dispersed on the surface of MWCNT.Cyclic voltammetry and chronoamperometric measurements indicated that the Pd-Au/MWCNT catalyst exhibited better electrocatalytic activity and stability for formic acid oxidation than that of the Pd/MWCNT catalyst.
2014, 31(1): 76-83
doi: 10.3724/SP.J.1095.2014.30098
Abstract:
Clew-like MnO2(CMnO2) with a specific capacitance of 154 F/g within a potential window of 0~1.0 V vs saturated calomel electrode has been synthesized by hydrothermally treating the precursor of as synthesized MnO2 in a solution of 1 mol/L NaOH at 150℃ for 12 h.The morphology and structure of the obtained material were examined by XRD,SEM and N2 adsorption-desorption.The capacitive properties were characterized by cyclic voltammetry,galvanostatic charge-discharge and electrochemical impedance spectroscopies.An asymmetrical electrochemical capacitor(EC) was assembled using CMnO2 as the positive electrode and graphene(GR) as the negative electrode,respectively.The asymmetrical EC can cycle reversibly in a cell potential of 0~1.8 V and gives a high energy density of 21.6 W·h/kg,which is much higher than those of symmetrical ECs based on CMnO2(4.86 W·h/kg) and GR(4.3 W·h/kg).Moreover,the asymmetrical EC presents a high power density(9 kW/kg at 8.1 W·h/kg) and excellent cycling performance of 83% retention after 1000 cycles.
Clew-like MnO2(CMnO2) with a specific capacitance of 154 F/g within a potential window of 0~1.0 V vs saturated calomel electrode has been synthesized by hydrothermally treating the precursor of as synthesized MnO2 in a solution of 1 mol/L NaOH at 150℃ for 12 h.The morphology and structure of the obtained material were examined by XRD,SEM and N2 adsorption-desorption.The capacitive properties were characterized by cyclic voltammetry,galvanostatic charge-discharge and electrochemical impedance spectroscopies.An asymmetrical electrochemical capacitor(EC) was assembled using CMnO2 as the positive electrode and graphene(GR) as the negative electrode,respectively.The asymmetrical EC can cycle reversibly in a cell potential of 0~1.8 V and gives a high energy density of 21.6 W·h/kg,which is much higher than those of symmetrical ECs based on CMnO2(4.86 W·h/kg) and GR(4.3 W·h/kg).Moreover,the asymmetrical EC presents a high power density(9 kW/kg at 8.1 W·h/kg) and excellent cycling performance of 83% retention after 1000 cycles.
2014, 31(1): 84-88
doi: 10.3724/SP.J.1095.2014.30090
Abstract:
A molecular imprinting polymer(MIP) using isocarbophos as template molecule,methacrylic acid as functional monomer,trimethylolpropane trimethacrylate(TRIM) as cross-linking agent was synthesized on the surface of silica gels.The MIP has been fully characterized by IR spectroscopy,SEM,elemental analysis and so on.The static adsorption equilibrium experiments and the Scatchard analysis showed that there were two kinds of binding sites in the MIP.The dissociation constants of these two binding sites are 4.84×10-3 and 15.2×10-3 mol/L,respectively.The MIP exhibits improved specific adsorption capacity compared with that of non-imprinted polymers.The imprint factor of MIP is 2.73.
A molecular imprinting polymer(MIP) using isocarbophos as template molecule,methacrylic acid as functional monomer,trimethylolpropane trimethacrylate(TRIM) as cross-linking agent was synthesized on the surface of silica gels.The MIP has been fully characterized by IR spectroscopy,SEM,elemental analysis and so on.The static adsorption equilibrium experiments and the Scatchard analysis showed that there were two kinds of binding sites in the MIP.The dissociation constants of these two binding sites are 4.84×10-3 and 15.2×10-3 mol/L,respectively.The MIP exhibits improved specific adsorption capacity compared with that of non-imprinted polymers.The imprint factor of MIP is 2.73.
2014, 31(1): 89-95
doi: 10.3724/SP.J.1095.2014.30081
Abstract:
The molecularly imprinted terpolymer was synthesized using pyrene as the template molecules by bulk polymerization.The adsorption ability and selectivity of the polymer were investigated by selectivity experiment.Scatchard analysis was employed to study the binding characteristics of molecularly imprinted polymer(MIP).Adsorption of polycyclic aromatic hydrocarbons(PAHs) was carried out to verify the interaction of MIP by solid phase extraction.The PAHs contents in the smoke of cigarette samples added with the MIPs to the filter were analyzed by GC/MS.The results show that the PYR-MIP is superior in terms of removing more than about 28% PAHs in the tobacco smoke.And the reduction rate of benzo[a]pyrene(B[a]P),benz(a) anthracene(B[a]A) and chrysene(CHR) are 31.08%,25.69% and 27.33%,respectively,compared the commercial filter tip.
The molecularly imprinted terpolymer was synthesized using pyrene as the template molecules by bulk polymerization.The adsorption ability and selectivity of the polymer were investigated by selectivity experiment.Scatchard analysis was employed to study the binding characteristics of molecularly imprinted polymer(MIP).Adsorption of polycyclic aromatic hydrocarbons(PAHs) was carried out to verify the interaction of MIP by solid phase extraction.The PAHs contents in the smoke of cigarette samples added with the MIPs to the filter were analyzed by GC/MS.The results show that the PYR-MIP is superior in terms of removing more than about 28% PAHs in the tobacco smoke.And the reduction rate of benzo[a]pyrene(B[a]P),benz(a) anthracene(B[a]A) and chrysene(CHR) are 31.08%,25.69% and 27.33%,respectively,compared the commercial filter tip.
2014, 31(1): 96-102
doi: 10.3724/SP.J.1095.2014.30086
Abstract:
A self-fabricated wall-jet/thin-layer electrochemical detector(ECD) was developed by combining the classical wall-jet and thin-layer ECD,which is coupled to high-performance liquid chromatography for simultaneous determination of five priority pollutants of phenols.The results show that both the response current and the noise increase with the increase of electrode area,thus an appropriate electrode area is important for obtaining a good analytical performance at enhanced signal-to-noise ratio(S/N).By using SHIM-PACK VP-ODS(150 mm×4.6 mm) column,mobile phase of a mixture of methanol and 0.1 mol/L PBS(pH=7.5)(volume ratio is 40:60),oven temperature:40℃,flow rate:1 mL/min,injection volume:20 μL,detection potential:1.0 V,detection wavelength:220 nm,the limits of detection without preconcentration are all lower than 1.0 μg/L(S/N=3) for p-nitrophenol,phenol,m-cresol,2,4-dichlorophenol and 2,4,6-trichlorophenol,which are lower than those obtained with a UV detector and a commercial electrochemical detector.The method has been tested using river water samples with satisfactory results.
A self-fabricated wall-jet/thin-layer electrochemical detector(ECD) was developed by combining the classical wall-jet and thin-layer ECD,which is coupled to high-performance liquid chromatography for simultaneous determination of five priority pollutants of phenols.The results show that both the response current and the noise increase with the increase of electrode area,thus an appropriate electrode area is important for obtaining a good analytical performance at enhanced signal-to-noise ratio(S/N).By using SHIM-PACK VP-ODS(150 mm×4.6 mm) column,mobile phase of a mixture of methanol and 0.1 mol/L PBS(pH=7.5)(volume ratio is 40:60),oven temperature:40℃,flow rate:1 mL/min,injection volume:20 μL,detection potential:1.0 V,detection wavelength:220 nm,the limits of detection without preconcentration are all lower than 1.0 μg/L(S/N=3) for p-nitrophenol,phenol,m-cresol,2,4-dichlorophenol and 2,4,6-trichlorophenol,which are lower than those obtained with a UV detector and a commercial electrochemical detector.The method has been tested using river water samples with satisfactory results.
2014, 31(1): 103-108
doi: 10.3724/SP.J.1095.2014.30082
Abstract:
The paper compared the characteristics of the hair samples from heroin and methamphetamineabusers based on the distribution characteristics of the two categories of drugs and their metabolists in hair.Analytes from heroin abuser's hair were collected in methanol by ultrasonication followed by liquid extraction at desirable pH.The methanol was evaporated to dryness and the residue was derivatized and detected by GC/MS.Hair from methamphetamine users was digested under alkali condition followed directly by small volume extraction in the solution.The analytes was derivatized in the extracted solution and detected by GC/MS.Two methods were validated by spiking standards in blank hair.The results show that the detection limits are 3 μg/g hair for 3 opioids(morphine,codeine and 6-monoacetyl morphine) with RSD of 2.5%~9.6%(n=5) and 0.05 μg/g hair for 4 amphetamines(amphetamine,methamphetamine,3,4-methylenedioxyamphetamine and 3,4-methylenedioxymethamphetamine) with RSD of 5%~14%(n=5),respectively.
The paper compared the characteristics of the hair samples from heroin and methamphetamineabusers based on the distribution characteristics of the two categories of drugs and their metabolists in hair.Analytes from heroin abuser's hair were collected in methanol by ultrasonication followed by liquid extraction at desirable pH.The methanol was evaporated to dryness and the residue was derivatized and detected by GC/MS.Hair from methamphetamine users was digested under alkali condition followed directly by small volume extraction in the solution.The analytes was derivatized in the extracted solution and detected by GC/MS.Two methods were validated by spiking standards in blank hair.The results show that the detection limits are 3 μg/g hair for 3 opioids(morphine,codeine and 6-monoacetyl morphine) with RSD of 2.5%~9.6%(n=5) and 0.05 μg/g hair for 4 amphetamines(amphetamine,methamphetamine,3,4-methylenedioxyamphetamine and 3,4-methylenedioxymethamphetamine) with RSD of 5%~14%(n=5),respectively.
2014, 31(1): 109-113
doi: 10.3724/SP.J.1095.2014.30065
Abstract:
A novel method for the determination of acetaminophen was developed based on its inhibition effect on the luminol-H2O2-silver nanoparticle chemiluminescence system.Various factors influencing the chemiluminescence system were investigated and the possible mechanism was also studied.Under the optimum conditions,the linear range for the determination of acetaminophen is 2.0×10-8 to 1.0×10-4 mol/L with a detection limit of 4.0×10-9 mol/L.The relative standard deviation is 2.6% for 1.0×10-7 mol/L acetaminophen solution in nine repeated measurements.The method was successfully applied to the determination of acetaminophen in pharmaceutical.
A novel method for the determination of acetaminophen was developed based on its inhibition effect on the luminol-H2O2-silver nanoparticle chemiluminescence system.Various factors influencing the chemiluminescence system were investigated and the possible mechanism was also studied.Under the optimum conditions,the linear range for the determination of acetaminophen is 2.0×10-8 to 1.0×10-4 mol/L with a detection limit of 4.0×10-9 mol/L.The relative standard deviation is 2.6% for 1.0×10-7 mol/L acetaminophen solution in nine repeated measurements.The method was successfully applied to the determination of acetaminophen in pharmaceutical.
2014, 31(1): 114-119
doi: 10.3724/SP.J.1095.2014.30232
Abstract:
The interaction between fish sperm DNA(fsDNA) and baicalein(BAI) in NaAc-HAc buffer(pH=3.22) was investigated by using cyclic voltammetry,square wave voltammetry,fluorescence spectroscopy,ultraviolet visible spectroscopy and viscosity measurement.Their interaction is in a groove binding mode and the complex has a higher electrical activity.The peak current of BAI is enhanced significantly because fsDNA provides a low polar hydrophobic environment.The enhanced peak current is in proportional to the concentration of fsDNA in the range of 7.0×10-8~7.0×10-6 g/mL.Based on this observstion,a new method with a detection limits at 4.1×10-8 g/mL for the determination of nucleic acids is established.
The interaction between fish sperm DNA(fsDNA) and baicalein(BAI) in NaAc-HAc buffer(pH=3.22) was investigated by using cyclic voltammetry,square wave voltammetry,fluorescence spectroscopy,ultraviolet visible spectroscopy and viscosity measurement.Their interaction is in a groove binding mode and the complex has a higher electrical activity.The peak current of BAI is enhanced significantly because fsDNA provides a low polar hydrophobic environment.The enhanced peak current is in proportional to the concentration of fsDNA in the range of 7.0×10-8~7.0×10-6 g/mL.Based on this observstion,a new method with a detection limits at 4.1×10-8 g/mL for the determination of nucleic acids is established.
2014, 31(1): 120-122
doi: 10.3724/SP.J.1095.2014.30075
Abstract:
An efficient and facile procedure for the synthesis of epoxiconazole from(Z)-3-(1H-1,2,4-triazole)-2-(4-fluorophenyl)-1-(2-chlorophenyl) propene was reported.An overall yield up to 80% can be achieved in the presence of pyridine-2-carboxylic acid manganese(Ⅱ) complex as catalyst and 30% mass fraction of hydrogen peroxide as terminal oxidant.This process has the potential for industrial scale up.
An efficient and facile procedure for the synthesis of epoxiconazole from(Z)-3-(1H-1,2,4-triazole)-2-(4-fluorophenyl)-1-(2-chlorophenyl) propene was reported.An overall yield up to 80% can be achieved in the presence of pyridine-2-carboxylic acid manganese(Ⅱ) complex as catalyst and 30% mass fraction of hydrogen peroxide as terminal oxidant.This process has the potential for industrial scale up.
