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2011 Volume 22 Issue 4
2011, 22(4): 379-381
doi: 10.1016/j.cclet.2010.11.013
Abstract:
The Passerini 3-CR adducts of substituted cinnamaldehydes, isocyanides and acetic acid were treated with SmI2/HMPA in dry tetrahydrofuran (THF) at room temperature, and β, γ-unsaturated amides were obtained in moderate yields. The reaction was supposed involving a radical reduction procedure.
The Passerini 3-CR adducts of substituted cinnamaldehydes, isocyanides and acetic acid were treated with SmI2/HMPA in dry tetrahydrofuran (THF) at room temperature, and β, γ-unsaturated amides were obtained in moderate yields. The reaction was supposed involving a radical reduction procedure.
2011, 22(4): 382-384
doi: 10.1016/j.cclet.2010.11.005
Abstract:
An aqueous solution of hydrogen peroxide and hydrogen bromide illuminated by a 60 W incandescent light bulb serves as a source of bromine radicals. Various substituted toluenes (NO2,Cl, Br, H, CH3) were high selectively brominated at the benzyl position for monobromination in CH2C12 at ice water with catalyst free. This simple but effective bromination of toluene derivatives with an aqueous H2O2-HBr system is characterized with the use of inexpensive reagents and a lower impact on the environment, which make it a good alternative to the existing bromination methods.
An aqueous solution of hydrogen peroxide and hydrogen bromide illuminated by a 60 W incandescent light bulb serves as a source of bromine radicals. Various substituted toluenes (NO2,Cl, Br, H, CH3) were high selectively brominated at the benzyl position for monobromination in CH2C12 at ice water with catalyst free. This simple but effective bromination of toluene derivatives with an aqueous H2O2-HBr system is characterized with the use of inexpensive reagents and a lower impact on the environment, which make it a good alternative to the existing bromination methods.
2011, 22(4): 385-388
doi: 10.1016/j.cclet.2010.10.039
Abstract:
A novel preparation of aluminum diethylphosphinate (AlPi) was carried out with free-radical addition reaction by means of UV-irradiation under atmospheric pressure. A solution of sodium hypophosphite was treated with ethylene and irradiated with ultraviolet light in the presence of an amount of photoinitiator effective to initiate the free-radical reaction between the hypophosphite anion and the double bond of the ethylene molecule. The ethylene was micro-bubbled into the reaction mixture with the addition of the photoinitiator, and the gas-liquid contact surface and the photoinitiator concentration in the gas-liquid interface were increased largely. The yield of the final product could be improved to about 96%. The contents of P, Al in samples were detected by ICP, and the molecular structure of the samples was confirmed by 31P NMR, 1H NMR and FTIR spectroscopic analysis. Thermal stability of the final products was investigated in detail by TG-DTA.
A novel preparation of aluminum diethylphosphinate (AlPi) was carried out with free-radical addition reaction by means of UV-irradiation under atmospheric pressure. A solution of sodium hypophosphite was treated with ethylene and irradiated with ultraviolet light in the presence of an amount of photoinitiator effective to initiate the free-radical reaction between the hypophosphite anion and the double bond of the ethylene molecule. The ethylene was micro-bubbled into the reaction mixture with the addition of the photoinitiator, and the gas-liquid contact surface and the photoinitiator concentration in the gas-liquid interface were increased largely. The yield of the final product could be improved to about 96%. The contents of P, Al in samples were detected by ICP, and the molecular structure of the samples was confirmed by 31P NMR, 1H NMR and FTIR spectroscopic analysis. Thermal stability of the final products was investigated in detail by TG-DTA.
2011, 22(4): 389-392
doi: 10.1016/j.cclet.2010.11.002
Abstract:
The condensation of o-phenylenediamines with 1,2-dicarbonyl compounds in the presence of citric acid afforded the corresponding quinoxaline derivatives in higher yields at room temperature in ethanol, and most of the reactions were completed in less than 1 min.
The condensation of o-phenylenediamines with 1,2-dicarbonyl compounds in the presence of citric acid afforded the corresponding quinoxaline derivatives in higher yields at room temperature in ethanol, and most of the reactions were completed in less than 1 min.
2011, 22(4): 393-396
doi: 10.1016/j.cclet.2010.11.003
Abstract:
The hydration of phenylacetylene in near-critical water, assisted with additives (NaHSO4, ZnCl2, FeCl3), has been successfully conducted with temperature and residence time ranges of 220-300℃ and 60-180 min, respectively. The results showed the catalytic ability is FeCl3 > ZnCl2 > NaHSO4. The maximum yield of product acetophenone was 96.68% at 260℃, 120 min. Based on the results found, a possible mechanism of hydration of phenylacetylene in near-critical water was proposed.
The hydration of phenylacetylene in near-critical water, assisted with additives (NaHSO4, ZnCl2, FeCl3), has been successfully conducted with temperature and residence time ranges of 220-300℃ and 60-180 min, respectively. The results showed the catalytic ability is FeCl3 > ZnCl2 > NaHSO4. The maximum yield of product acetophenone was 96.68% at 260℃, 120 min. Based on the results found, a possible mechanism of hydration of phenylacetylene in near-critical water was proposed.
2011, 22(4): 397-400
doi: 10.1016/j.cclet.2010.11.007
Abstract:
A stereoselective and effective method for the synthesis of vinyl thioethers has been developed. This method is based on the Michael addition of ethanethiol to various alkynyl ketones using 10 mol% of tributylphosphine as catalyst. Most of alkynyl ketones react with ethanethiol in this system to yield mainly Z-isomer of vinyl thioether adducts, only in one case mainly E-isomer of vinyl thioether adducts was observed.
A stereoselective and effective method for the synthesis of vinyl thioethers has been developed. This method is based on the Michael addition of ethanethiol to various alkynyl ketones using 10 mol% of tributylphosphine as catalyst. Most of alkynyl ketones react with ethanethiol in this system to yield mainly Z-isomer of vinyl thioether adducts, only in one case mainly E-isomer of vinyl thioether adducts was observed.
2011, 22(4): 401-404
doi: 10.1016/j.cclet.2010.10.035
Abstract:
MgAl and MgMAl oxides (M=Co, Ni and Cu) with a Mg:M:Al molar ratio=4:1:1 were synthesized from the calcination of their corresponding layered double hydroxide (LDHs) precursors. Their catalytic activities were examined for the oxidation of ethylbenzene using tert-butylhydroperoxide (TBHP) as an oxidant. The oxidized product was mainly acetophenone. The catalytic activities were in the order of MgCuAl> MgNiAl~NiAl~MgCoAl~CoAl > CuAl > MgAl oxides. Reusability studies show that the catalysts are stable under the reaction conditions.
MgAl and MgMAl oxides (M=Co, Ni and Cu) with a Mg:M:Al molar ratio=4:1:1 were synthesized from the calcination of their corresponding layered double hydroxide (LDHs) precursors. Their catalytic activities were examined for the oxidation of ethylbenzene using tert-butylhydroperoxide (TBHP) as an oxidant. The oxidized product was mainly acetophenone. The catalytic activities were in the order of MgCuAl> MgNiAl~NiAl~MgCoAl~CoAl > CuAl > MgAl oxides. Reusability studies show that the catalysts are stable under the reaction conditions.
2011, 22(4): 405-408
doi: 10.1016/j.cclet.2010.10.020
Abstract:
An efficient and simple method for synthesis of new hyodeoxycholic acid thiosemicarbazone derivatives under solvent-free conditions using microwave has been developed. Its main advantages are short reaction times, good conversions and the environmentally friendly nature of the process. The preliminary results indicate that some of these compounds possess inhibitory effects against E. coli.
An efficient and simple method for synthesis of new hyodeoxycholic acid thiosemicarbazone derivatives under solvent-free conditions using microwave has been developed. Its main advantages are short reaction times, good conversions and the environmentally friendly nature of the process. The preliminary results indicate that some of these compounds possess inhibitory effects against E. coli.
2011, 22(4): 409-412
doi: 10.1016/j.cclet.2010.11.008
Abstract:
A series of diclofenac derivatives were synthesized. The insulin-sensitizing activity of 28 new compounds was evaluated in 3T3-L1 cells. The compounds 10a and 10f exhibited similar insulin-sensitizing activity with positive drag rosiglitazone.
A series of diclofenac derivatives were synthesized. The insulin-sensitizing activity of 28 new compounds was evaluated in 3T3-L1 cells. The compounds 10a and 10f exhibited similar insulin-sensitizing activity with positive drag rosiglitazone.
2011, 22(4): 413-416
doi: 10.1016/j.cclet.2010.10.036
Abstract:
A series of furoxan-based novel nitric oxide-donating ursolic acid (UA) derivatives (7a-f) were synthesized, and their cytotoxic activities against HepG2 cells in vitro were evaluated by MTT method. It was found that 7a-d and 7f showed more potent cytotoxic activities than control 5-fluorouracil and UA.
A series of furoxan-based novel nitric oxide-donating ursolic acid (UA) derivatives (7a-f) were synthesized, and their cytotoxic activities against HepG2 cells in vitro were evaluated by MTT method. It was found that 7a-d and 7f showed more potent cytotoxic activities than control 5-fluorouracil and UA.
2011, 22(4): 417-420
doi: 10.1016/j.cclet.2010.10.048
Abstract:
A simple and efficient methodology for Markovnikov addition of azoles with vinyl acetate catalyzed by potassium tert-butoxide is described. N-heterocyclic compounds are synthesized from simple and commercially available starting materials under mild conditions in high yields.
A simple and efficient methodology for Markovnikov addition of azoles with vinyl acetate catalyzed by potassium tert-butoxide is described. N-heterocyclic compounds are synthesized from simple and commercially available starting materials under mild conditions in high yields.
2011, 22(4): 421-423
doi: 10.1016/j.cclet.2010.10.034
Abstract:
A mild and efficient method for the oxidative deprotection of 1,3-oxathiolanes with Fe(NO3)3·9H2O and Cu(NO3)2·3H2O in the absence of solvent is reported.
A mild and efficient method for the oxidative deprotection of 1,3-oxathiolanes with Fe(NO3)3·9H2O and Cu(NO3)2·3H2O in the absence of solvent is reported.
2011, 22(4): 424-426
doi: 10.1016/j.cclet.2010.11.010
Abstract:
A novel reactive polycarboxylic acid dye was synthesized by the reaction of polymaleic anhydride (PMA) with 3-methyl-l-(4-sulfonylphenyl)-4-(4-aminophenylazo)-2-pyrazoline-5-one. The structure of the novel dye was characterized by FTIR, UV-vis and 13C NMR spectra. The dyeing properties of dye on cotton were tested, and the novel dye possessed high fixation and good fastness.
A novel reactive polycarboxylic acid dye was synthesized by the reaction of polymaleic anhydride (PMA) with 3-methyl-l-(4-sulfonylphenyl)-4-(4-aminophenylazo)-2-pyrazoline-5-one. The structure of the novel dye was characterized by FTIR, UV-vis and 13C NMR spectra. The dyeing properties of dye on cotton were tested, and the novel dye possessed high fixation and good fastness.
2011, 22(4): 427-430
doi: 10.1016/j.cclet.2010.10.038
Abstract:
2-Substituted-2,3-dihydro-4(1H)-quinazolinones were synthesized in high yield by condensation of 2-anthranilamide with aromatic aldehydes or ketones in refluxing water without catalyst. This protocol has advantages of high yield, simple work-up and environmental friendly procedure.
2-Substituted-2,3-dihydro-4(1H)-quinazolinones were synthesized in high yield by condensation of 2-anthranilamide with aromatic aldehydes or ketones in refluxing water without catalyst. This protocol has advantages of high yield, simple work-up and environmental friendly procedure.
2011, 22(4): 431-434
doi: 10.1016/j.cclet.2010.11.014
Abstract:
The effective chlorolactonization of alkenoic acids with (diacetoxyiodo)benzene and lithium chloride under mild conditions have been studied. Experiments show that various 4-pentenoic acids react with (diacetoxyiodo)benzene and lithium chloride fluently in CH3OH at room temperature, obtaining five-membered chlorolactones in good yields in short times. Other alkenoic acids, such as 3-butenoic acid and trans 3-hexenoic acid give some more complicated results, and 4-pentynoic acid provides a chloroenol lactone with Z configuration in 40% of yield.
The effective chlorolactonization of alkenoic acids with (diacetoxyiodo)benzene and lithium chloride under mild conditions have been studied. Experiments show that various 4-pentenoic acids react with (diacetoxyiodo)benzene and lithium chloride fluently in CH3OH at room temperature, obtaining five-membered chlorolactones in good yields in short times. Other alkenoic acids, such as 3-butenoic acid and trans 3-hexenoic acid give some more complicated results, and 4-pentynoic acid provides a chloroenol lactone with Z configuration in 40% of yield.
2011, 22(4): 435-438
doi: 10.1016/j.cclet.2010.10.052
Abstract:
Preyssler-type heteropoly acid is introduced as a new, mild and efficient catalyst for protection of a variety of carbonyl compounds with 1,3-propane dithiol.
Preyssler-type heteropoly acid is introduced as a new, mild and efficient catalyst for protection of a variety of carbonyl compounds with 1,3-propane dithiol.
2011, 22(4): 439-442
doi: 10.1016/j.cclet.2010.10.040
Abstract:
Fully conjugated Schiff base macrocycle has been prepared through a simple and mild condition, a one-pot cyclization procedure of four-component without using a template. The condensation reaction of related bis (hydroxybenzaldehyde) with phenylenediamines to prepare a conjugated[2+2] Schiff base macrocycle has been investigated and fluorescent[2+2] Schiff base macrocycles with N2O2 binding pockets has been prepared and characterized by elemental analysis,1H NMR, IR, fluorescent, UV-visible and MALDI mass spectroscopies.
Fully conjugated Schiff base macrocycle has been prepared through a simple and mild condition, a one-pot cyclization procedure of four-component without using a template. The condensation reaction of related bis (hydroxybenzaldehyde) with phenylenediamines to prepare a conjugated[2+2] Schiff base macrocycle has been investigated and fluorescent[2+2] Schiff base macrocycles with N2O2 binding pockets has been prepared and characterized by elemental analysis,1H NMR, IR, fluorescent, UV-visible and MALDI mass spectroscopies.
2011, 22(4): 443-446
doi: 10.1016/j.cclet.2010.11.015
Abstract:
The carbodiimide 2, obtained from the aza-Wittig reactions of iminophosphorane 1 with alkyl isocyanates, reacted with primary amino to give 2-alkylamino benzo[b]thieno[3,2-d]pyrimidin-4(3H)-ones 4 and 5. The formation mechanism of the title compounds has been investigated.
The carbodiimide 2, obtained from the aza-Wittig reactions of iminophosphorane 1 with alkyl isocyanates, reacted with primary amino to give 2-alkylamino benzo[b]thieno[3,2-d]pyrimidin-4(3H)-ones 4 and 5. The formation mechanism of the title compounds has been investigated.
2011, 22(4): 447-450
doi: 10.1016/j.cclet.2010.10.023
Abstract:
1,3,5-Trisubstituted pyrazolines are rapidly and conveniently oxidized to their corresponding pyrazoles by l,3-dichloro-5,5-dimethylhydantoin (DCH) in solution and solvent-free conditions under microwave irradiation. The presence of silica gel as a supporting agent is shown to be effective in reducing the reaction times and increasing the yields.
1,3,5-Trisubstituted pyrazolines are rapidly and conveniently oxidized to their corresponding pyrazoles by l,3-dichloro-5,5-dimethylhydantoin (DCH) in solution and solvent-free conditions under microwave irradiation. The presence of silica gel as a supporting agent is shown to be effective in reducing the reaction times and increasing the yields.
2011, 22(4): 451-454
doi: 10.1016/j.cclet.2010.11.001
Abstract:
Methanolic extract of Euphorbia cornigera Boiss. on HPLC separation yielded three new compounds. Their structures and relative stereochemistry were established through 2D-NMR spectroscopic measurements.
Methanolic extract of Euphorbia cornigera Boiss. on HPLC separation yielded three new compounds. Their structures and relative stereochemistry were established through 2D-NMR spectroscopic measurements.
2011, 22(4): 455-457
doi: 10.1016/j.cclet.2010.11.009
Abstract:
A novel flavanol bearing phenylpropionic acid moiety at C-4 through a C-C bonding, named brainin A (1), was isolated from the rhizomes of Brainea insignis. Its structure was elucidated on the basis of spectral data including 2D NMR and HR-ESI-MS.
A novel flavanol bearing phenylpropionic acid moiety at C-4 through a C-C bonding, named brainin A (1), was isolated from the rhizomes of Brainea insignis. Its structure was elucidated on the basis of spectral data including 2D NMR and HR-ESI-MS.
2011, 22(4): 458-460
doi: 10.1016/j.cclet.2010.12.009
Abstract:
Ag nanoparticles were prepared by using the ion-exchange of Nafion combined with electrochemical reduction on the electrode. Ag nanoparticles are highly dispersed in Nafion film with an average size of 4.0±0.2 nm. The amount of Ag nanoparticles can be readily controlled by the amount of Nafion coated on the electrode. Thus obtained Ag nanoparticles exhibit good catalytic activity for the reduction of H2O2 with a linear response to H2O2 in the concentration range of 0.04-8.0 mmol/L with a sensitivity of 0.34 μA/mmol/L and a detection limit of 1.0×10-8 mol/L.
Ag nanoparticles were prepared by using the ion-exchange of Nafion combined with electrochemical reduction on the electrode. Ag nanoparticles are highly dispersed in Nafion film with an average size of 4.0±0.2 nm. The amount of Ag nanoparticles can be readily controlled by the amount of Nafion coated on the electrode. Thus obtained Ag nanoparticles exhibit good catalytic activity for the reduction of H2O2 with a linear response to H2O2 in the concentration range of 0.04-8.0 mmol/L with a sensitivity of 0.34 μA/mmol/L and a detection limit of 1.0×10-8 mol/L.
2011, 22(4): 461-464
doi: 10.1016/j.cclet.2010.11.011
Abstract:
An ion chromatography (IC) system coupled with on-line column-switching technique was used to determine anions of μg/g levels in organic chemicals of analytical reagent grade. A novel polystyrene-divinylbenzene-carbon nanotube (PS-DVB-CNT) stationary phase was utilized for matrix elimination. A calibration study was conducted by preparing and analyzing eight concentrations (between 10 and 5000 μg/L) of eight standards in deionized water. The linearity was between 0.9978 and 1. And the detection limits ranged from 1.54 μg/L to 10.02 μg/L. A spiking study was performed on two representative organic chemicals. The recoveries were between 84.3% and 119.6%.
An ion chromatography (IC) system coupled with on-line column-switching technique was used to determine anions of μg/g levels in organic chemicals of analytical reagent grade. A novel polystyrene-divinylbenzene-carbon nanotube (PS-DVB-CNT) stationary phase was utilized for matrix elimination. A calibration study was conducted by preparing and analyzing eight concentrations (between 10 and 5000 μg/L) of eight standards in deionized water. The linearity was between 0.9978 and 1. And the detection limits ranged from 1.54 μg/L to 10.02 μg/L. A spiking study was performed on two representative organic chemicals. The recoveries were between 84.3% and 119.6%.
2011, 22(4): 465-468
doi: 10.1016/j.cclet.2010.11.012
Abstract:
Direct electrochemistry and electrocatalysis of myoglobin (Mb) were studied with Mb immobilized on dodecyltrimethylammonium bromide (DTAB) film modified carbon ceramic (CC) electrode. Cyclic voltammetry showed a pair of well-defined and nearly reversible redox peaks of Mb (FeⅡ/FeⅢ) at about -0.3 V vs. SCE (pH=6.98). The currents of the redox peak were linear to scan rate, and rate constant (Ks) was estimated to be 3.03 s-1. The formal potential (E°') of Mb in the DTAB/CC electrodes shifted linearly with pH with a slope of -36.44 mV/pH, implying that the electron transfer between DTAB and CC electrodes is accompanied by proton transportation. The immobilized Mb exhibited excellent electrocatalytic response to the reduction of hydrogen peroxide (H2O2).
Direct electrochemistry and electrocatalysis of myoglobin (Mb) were studied with Mb immobilized on dodecyltrimethylammonium bromide (DTAB) film modified carbon ceramic (CC) electrode. Cyclic voltammetry showed a pair of well-defined and nearly reversible redox peaks of Mb (FeⅡ/FeⅢ) at about -0.3 V vs. SCE (pH=6.98). The currents of the redox peak were linear to scan rate, and rate constant (Ks) was estimated to be 3.03 s-1. The formal potential (E°') of Mb in the DTAB/CC electrodes shifted linearly with pH with a slope of -36.44 mV/pH, implying that the electron transfer between DTAB and CC electrodes is accompanied by proton transportation. The immobilized Mb exhibited excellent electrocatalytic response to the reduction of hydrogen peroxide (H2O2).
2011, 22(4): 469-472
doi: 10.1016/j.cclet.2010.10.037
Abstract:
The development of economic and environmentally friendly extractants to recover cobalt metal is required due to the increasing demand for this metal. In this study, solvent extraction of Co(Ⅱ) from aqueous solution using a mixture of N,N'-carbonyl difatty amides (CDFAs) synthesised from palm oil as the extractant was carried out. The effects of various parameters such as acid, contact time, extractant concentration, metal ion concentration and stripping agent and the separation of Co(Ⅱ) from other metal ions such as Fe(Ⅱ), Ni(Ⅱ), Zn(Ⅲ) and Cd(Ⅱ) were investigated. It was found that the extraction of Co(Ⅱ) into the organic phase involved the formation of 1:1 complexes. Co(Ⅱ) was successfully separated from commonly associated metal ions such as Fe(Ⅱ), Ni(Ⅱ), Zn(Ⅲ) and Cd(Ⅱ). Co(Ⅱ) stripping from the loaded organic phase was studied in aqueous solution. These results are useful to recover Co(Ⅱ) from aqueous solution utilising (CDFAs) as an extractant.
The development of economic and environmentally friendly extractants to recover cobalt metal is required due to the increasing demand for this metal. In this study, solvent extraction of Co(Ⅱ) from aqueous solution using a mixture of N,N'-carbonyl difatty amides (CDFAs) synthesised from palm oil as the extractant was carried out. The effects of various parameters such as acid, contact time, extractant concentration, metal ion concentration and stripping agent and the separation of Co(Ⅱ) from other metal ions such as Fe(Ⅱ), Ni(Ⅱ), Zn(Ⅲ) and Cd(Ⅱ) were investigated. It was found that the extraction of Co(Ⅱ) into the organic phase involved the formation of 1:1 complexes. Co(Ⅱ) was successfully separated from commonly associated metal ions such as Fe(Ⅱ), Ni(Ⅱ), Zn(Ⅲ) and Cd(Ⅱ). Co(Ⅱ) stripping from the loaded organic phase was studied in aqueous solution. These results are useful to recover Co(Ⅱ) from aqueous solution utilising (CDFAs) as an extractant.
2011, 22(4): 473-476
doi: 10.1016/j.cclet.2010.10.049
Abstract:
A novel, simple, rapid, efficient and environment-friendly method for the determination of trace copper in cereal samples was developed by using dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFO) followed by flame atomic absorption spectrometry. In the DLLME-SFO, copper was complexed with 8-hydroxy quinoline and extracted into a small volume of 1-dodecanol, which is of low density, low toxicity and proper melting point near room temperature. The experimental parameters affecting the extraction efficiency were investigated and optimized. Under the optimum conditions, the calibration graph exhibited linearity over the range of 0.5-500 ng/mL with the correlation coefficient (r) of 0.9996. The enrichment factor was 122 and the limit of detection was 0.1 ng/mL. The method was applied to the determination of copper in the complex matrix samples such as rice and millet with the recoveries for the spiked samples at 5.0 and 10.0 μg/g falling in the range of 92.0-98.0% and the relative standard deviation of 3.9-5.7%.
A novel, simple, rapid, efficient and environment-friendly method for the determination of trace copper in cereal samples was developed by using dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFO) followed by flame atomic absorption spectrometry. In the DLLME-SFO, copper was complexed with 8-hydroxy quinoline and extracted into a small volume of 1-dodecanol, which is of low density, low toxicity and proper melting point near room temperature. The experimental parameters affecting the extraction efficiency were investigated and optimized. Under the optimum conditions, the calibration graph exhibited linearity over the range of 0.5-500 ng/mL with the correlation coefficient (r) of 0.9996. The enrichment factor was 122 and the limit of detection was 0.1 ng/mL. The method was applied to the determination of copper in the complex matrix samples such as rice and millet with the recoveries for the spiked samples at 5.0 and 10.0 μg/g falling in the range of 92.0-98.0% and the relative standard deviation of 3.9-5.7%.
2011, 22(4): 477-480
doi: 10.1016/j.cclet.2010.11.004
Abstract:
Molecular imprinting technology is applied in surface plasmon resonance spectroscopy for highly sensitive and selective detection of morphine (MO). As SPR-based sensor of MO, the preparation of molecular imprinted polymer is as follows:methacrylic acids (MAA), ethylene glycol dimethacrylate (EGDMA), azodiisobutyronitrile (AIBN) were used as functional monomer, cross-linker and initiator, respectively. The experiment results showed that morphine imprinted polymer had the performance of high sensitivity and specificity, i.e. the relative signal of SPR response was proportional to the concentration of morphine in acetonitrile in the range of 10-9 mol/L to 10-6mol/L (1 ppb-1 ppm) with LOD of 10-10mol/L, and MO was distinguished from its analogs, such as codeine.
Molecular imprinting technology is applied in surface plasmon resonance spectroscopy for highly sensitive and selective detection of morphine (MO). As SPR-based sensor of MO, the preparation of molecular imprinted polymer is as follows:methacrylic acids (MAA), ethylene glycol dimethacrylate (EGDMA), azodiisobutyronitrile (AIBN) were used as functional monomer, cross-linker and initiator, respectively. The experiment results showed that morphine imprinted polymer had the performance of high sensitivity and specificity, i.e. the relative signal of SPR response was proportional to the concentration of morphine in acetonitrile in the range of 10-9 mol/L to 10-6mol/L (1 ppb-1 ppm) with LOD of 10-10mol/L, and MO was distinguished from its analogs, such as codeine.
2011, 22(4): 481-484
doi: 10.1016/j.cclet.2010.10.043
Abstract:
A V-shaped spacroscopic cell (V-cell) was constructed using two CaF2 optical plates for FTIR light transparent measurements in the range of 4000-1000 cm-1. The spectrum of ethanol was characterized with the standard spectra, excellent fitting was achieved with a bottom-width correction method. The principle of the V-cell was discussed, giving equations for the data interpretation. It shows that the V-cell is an auto-focus type spectroscopic cell, which can effectively avoid absorption saturation with amplifications for weak absorption bands. The V-cell design is simple and effective, easy to operate, suitable for applications in liquid samples with high absorption bands, willing to have broad application prospects.
A V-shaped spacroscopic cell (V-cell) was constructed using two CaF2 optical plates for FTIR light transparent measurements in the range of 4000-1000 cm-1. The spectrum of ethanol was characterized with the standard spectra, excellent fitting was achieved with a bottom-width correction method. The principle of the V-cell was discussed, giving equations for the data interpretation. It shows that the V-cell is an auto-focus type spectroscopic cell, which can effectively avoid absorption saturation with amplifications for weak absorption bands. The V-cell design is simple and effective, easy to operate, suitable for applications in liquid samples with high absorption bands, willing to have broad application prospects.
2011, 22(4): 485-488
doi: 10.1016/j.cclet.2010.10.047
Abstract:
A novel nanodiamond-epoxy derivative (ND-EP) was synthesized by grafting epoxy monomers onto the surface of nanodiamond (ND), and characterized by FTIR and TGA. The ratio of grafted epoxy groups was determined to be 32.5 wt% by TGA. The developed methodology provides an efficient method for the functionalization of nanodiamond material, which enables a variety of advanced engineering and biomedical applications of ND.
A novel nanodiamond-epoxy derivative (ND-EP) was synthesized by grafting epoxy monomers onto the surface of nanodiamond (ND), and characterized by FTIR and TGA. The ratio of grafted epoxy groups was determined to be 32.5 wt% by TGA. The developed methodology provides an efficient method for the functionalization of nanodiamond material, which enables a variety of advanced engineering and biomedical applications of ND.
2011, 22(4): 489-492
doi: 10.1016/j.cclet.2010.10.022
Abstract:
Precipitation polymerizations of divinylbenzene (DVB) in pure supercritical carbon dioxide, and parallel runs with presence of a cosolvent were carried out. The results showed that use of acetone as the cosolvent contributed greatly to the formation of the monodisperse microspheres. PDVB microspheres, with obviously higher uniformity than reported up to date, were achieved using 6-7 mL of acetone in a reactor of 50 mL with DVB concentration of 0.4 mol/L under 16 MPa, a much lower pressure than previously reported without use of cosolvent.
Precipitation polymerizations of divinylbenzene (DVB) in pure supercritical carbon dioxide, and parallel runs with presence of a cosolvent were carried out. The results showed that use of acetone as the cosolvent contributed greatly to the formation of the monodisperse microspheres. PDVB microspheres, with obviously higher uniformity than reported up to date, were achieved using 6-7 mL of acetone in a reactor of 50 mL with DVB concentration of 0.4 mol/L under 16 MPa, a much lower pressure than previously reported without use of cosolvent.
2011, 22(4): 493-496
doi: 10.1016/j.cclet.2010.10.050
Abstract:
Firstly, we synthesized N-methacryloyl-histidine monomer and N-methacryIoyl-histidine-Cu2+ complex (MAH-Cu2+). Then the molecular imprinting polymers (MIP) has been prepared by surface grafting on uniform polystyrene (PS) core using reversible addition-fragmentation transfer polymerization (RAFT) with MAH-Cu2+ as the functional monomer, methyl paraoxon as the template to simulate phosphotriesterase (PTE). Finally, we have investigated the catalytic hydrolytic activities of MIP and non-imprinting polymers (NIP) to the template methyl paraoxon and the template analogue ethyl paraoxon respectively by UV spectrophotometry. The results showed that the catalytic hydrolytic activity of MIP to the template methyl paraoxon was highest and the value of k is 8.67×10-5 mmol L-1 min-1 3.89-fold higher than MIP to the template analogue ethyl paraoxon, 2.79-fold higher than NIP to the template methyl paraoxon. The KM, rm of MIP are also determined, and Km=3.95×10-4 mol/L, rm=2.12 μmol/min. The MIP can be reused with only lose 7% of catalytic activity for four cycles.
Firstly, we synthesized N-methacryloyl-histidine monomer and N-methacryIoyl-histidine-Cu2+ complex (MAH-Cu2+). Then the molecular imprinting polymers (MIP) has been prepared by surface grafting on uniform polystyrene (PS) core using reversible addition-fragmentation transfer polymerization (RAFT) with MAH-Cu2+ as the functional monomer, methyl paraoxon as the template to simulate phosphotriesterase (PTE). Finally, we have investigated the catalytic hydrolytic activities of MIP and non-imprinting polymers (NIP) to the template methyl paraoxon and the template analogue ethyl paraoxon respectively by UV spectrophotometry. The results showed that the catalytic hydrolytic activity of MIP to the template methyl paraoxon was highest and the value of k is 8.67×10-5 mmol L-1 min-1 3.89-fold higher than MIP to the template analogue ethyl paraoxon, 2.79-fold higher than NIP to the template methyl paraoxon. The KM, rm of MIP are also determined, and Km=3.95×10-4 mol/L, rm=2.12 μmol/min. The MIP can be reused with only lose 7% of catalytic activity for four cycles.
2011, 22(4): 497-500
doi: 10.1016/j.cclet.2010.10.051
Abstract:
The polyporous carbon supported tungsten carbide (polyporous C@WC1-x) composite was prepared using hexagonal silica MCM-41 as the hard template by raw material solution impregnation, mechanical milling and simultaneous reduction and carbonization by temperature programming in mixture gas (CH4/H2). The structure and morphology of polyporous C@WC1-x composite were studied via X-ray diffraction, transmission electron microscopy and so on. The electrocatalytic property was tested for the electroreduction of p-nitrophenol (PNP) in neutral media. Results revealed that the composite is consisted of polyporous carbon and nanocrystalline WC1-x, possessing good electrocatalytic activity in the reaction of PNP reduction.
The polyporous carbon supported tungsten carbide (polyporous C@WC1-x) composite was prepared using hexagonal silica MCM-41 as the hard template by raw material solution impregnation, mechanical milling and simultaneous reduction and carbonization by temperature programming in mixture gas (CH4/H2). The structure and morphology of polyporous C@WC1-x composite were studied via X-ray diffraction, transmission electron microscopy and so on. The electrocatalytic property was tested for the electroreduction of p-nitrophenol (PNP) in neutral media. Results revealed that the composite is consisted of polyporous carbon and nanocrystalline WC1-x, possessing good electrocatalytic activity in the reaction of PNP reduction.
2011, 22(4): 501-504
doi: 10.1016/j.cclet.2010.10.041
Abstract:
The modified Fe3O4 nano-particles with the extracted pectin from the cell wall of Azolla filicoloides (FN-EP) can remove methyl orange as a water-soluble azo dye from waste water better than Azolla and the extracted pectin from Azolla (EPA), alone. It could be due to more crowding the main functional groups of uptake after binding pectin with nano-particles. Thermodynamic studies showed that adsorption equilibrium constant (KL) and maximum adsorption capacities (Qmax) were increased with decreasing temperature (exothermic). The maximum uptake capacity (Qmax) of dye by FN-EP in a batch reactor was 0.533, 0.498 and 0.446 mmol/g at 5, 25 and 50℃, respectively. The enthalpy change (△H) and entropy change (△S) were-15.31 kJ/mol and-0.02434 kJ/mol K, respectively.
The modified Fe3O4 nano-particles with the extracted pectin from the cell wall of Azolla filicoloides (FN-EP) can remove methyl orange as a water-soluble azo dye from waste water better than Azolla and the extracted pectin from Azolla (EPA), alone. It could be due to more crowding the main functional groups of uptake after binding pectin with nano-particles. Thermodynamic studies showed that adsorption equilibrium constant (KL) and maximum adsorption capacities (Qmax) were increased with decreasing temperature (exothermic). The maximum uptake capacity (Qmax) of dye by FN-EP in a batch reactor was 0.533, 0.498 and 0.446 mmol/g at 5, 25 and 50℃, respectively. The enthalpy change (△H) and entropy change (△S) were-15.31 kJ/mol and-0.02434 kJ/mol K, respectively.
