The development of analytical methods for antibiotic detection has become crucial for public health.In this research,a novel and simple electrochemical sensor for sensitive detection of cefadroxil(CFL)antibiotic was d...The development of analytical methods for antibiotic detection has become crucial for public health.In this research,a novel and simple electrochemical sensor for sensitive detection of cefadroxil(CFL)antibiotic was developed.The glassy carbon electrode(GCE)was coated with cheap conductive carbon black VXC-72R that was decorated with tetrabutylammonium tetrafluoroborate(TBABF_(4)),to construct the electrochemical sensor TBABF_(4)/VXC-72R/GCE.It was found that CFL exhibited a reduction peak at approximately 0.22 V on TBABF_(4)/VXC-72R/GCE.TBABF_(4)/VXC-72R/GCE showed a linear response to CFL in a concentration range of 0.3-10.0μmol/L,with a detection limit of 0.2μmol/L(a signal-to-noise ratio of 3).TBABF_(4)/VXC-72R/GCE showed good reproducibility,high storage stability and anti-interference performance.Analytical applications for CFL detection in real lake water,pharmaceutical tablet and fetal bovine serum samples were achieved.展开更多
A simple and efficient procedure for the synthesis of 2-arylquinazolin-4（3H）-ones has been developed through cyclocondensation of 2-aminobenzamide with aromatic aldehydes using tetrabutylammonium bromide（TBAB） as ...A simple and efficient procedure for the synthesis of 2-arylquinazolin-4（3H）-ones has been developed through cyclocondensation of 2-aminobenzamide with aromatic aldehydes using tetrabutylammonium bromide（TBAB） as novel neutral ionic liquid catalyst in the presence of copper（Ⅱ） chloride（CuCl;） as oxidizing agent under solvent-free conditions at 100℃.In the absence of CuCl;and under a nitrogen atmosphere,the unoxidized intermediates,2-aryl-2,3-dihydroquinazolin-4（1H）-ones,were isolated. Treatment of these intermediates with CuCl;in TBAB media gave the oxidized products 2-arylquinazolin-4（3H）-ones.On the other hand,cyclocondensation of 2-aminobenzamide with aromatic aldehydes in TBAB under microwave irradiation directly gave 2- arylquinazolin-4（3H）-ones.展开更多
In this article tetrabutylammonium bromide （TBAB） was first added in buffer to compose a convenient and environmentally friendly system, and enzymatic polymerization of phenol catalyzed by horseradish peroxidase （...In this article tetrabutylammonium bromide （TBAB） was first added in buffer to compose a convenient and environmentally friendly system, and enzymatic polymerization of phenol catalyzed by horseradish peroxidase （HRP） could proceed efficiently in this system. When TBAB was added, the most conversion of phenol could reach 99.1%. The phenol polymer was considered to consist of a mixture of phenylene （Ph） and oxyphenylene （Ox） units by IR analysis, and the ratio of phenylene to oxyphenylene units （Ph/Ox） was measured by titration. Moreover, the effects of the dosage of horseradish peroxidase （HRP） and pH value on the conversion of phenol were investigated. The reaction performed very effectively in this novel system when the addition of HRP was only 0.2 mg. In all cases, the weight-average molecular weight calculated by GPC-SLS was in a range from 12000 Da to 30000 Da. The phenol polymer prepared in the present research possessed good thermal stability shown by TG analysis.展开更多
The title heteropoly blue, (Bu_4N)_6H_(10)[PMo_(11)~ⅥMo~ⅤO_(40)]_4·H_2Ohas been photochemically synthesized and characterized with elemental analysis, solid diffusionreflectance electronic spectra, CV, ESR, XPS...The title heteropoly blue, (Bu_4N)_6H_(10)[PMo_(11)~ⅥMo~ⅤO_(40)]_4·H_2Ohas been photochemically synthesized and characterized with elemental analysis, solid diffusionreflectance electronic spectra, CV, ESR, XPS, IR spectra, conductivity measurement and X-ray singlecrystal analysis. The crystallographic data for C_(96)H_(218)Mo_(48)N_6O_(169)P_4 are as follows:M_r = 8889.76, triclinic, P_1, a = 1.4142(3) nm, b = 2.6027(5) nm, c = 2.6403(5) nm, α=113.96(3)°, β = 90.05(3)°, γ= 105.71(3)°, V = 8.481(3) nm^3, Z = 1, D_c = 1.741 g/cm^3, F(000)= 4264, μ= 1.798 mm^(-1). The X-ray crystal structure analysis reveals that there is oneindependent molecule in the unit cell of the title heteropoly blue which contains four mixed-valenceheteropoly anions, six tetrabutylammonium cations and one water molecule. Its molecular structurepossesses a centrosymmetrical arrangement in the unit cell. The phosphorus atom is in thecrystallographic inversion center of the heteropoly anion and the eight oxygen atoms surroundingcentral phosphorus atom comprise of a distorted hexahedron. Heteropoly anion has two equal sets ofPO_4 tetrahedron. The PO_4 tetrahedron and the MoO_6 octahedron in the polyanion are greatlydistorted.展开更多
The electrochemical behaviors of Ta in tetrabutylammonium hydrogen sulfate（TBAHS） ethanol solutions were studied using potentiodynamic polarization,cyclic voltammetry,potentiostatic current time transient and impeda...The electrochemical behaviors of Ta in tetrabutylammonium hydrogen sulfate（TBAHS） ethanol solutions were studied using potentiodynamic polarization,cyclic voltammetry,potentiostatic current time transient and impedance techniques.The results revealed that no active-passive transition is presented in the cyclic voltammogram,and the anodic current density increases with the increase of solution temperature,TBAHS concentration,potential scan rate and water content.The apparent activation energy is about 43.389 kJ/mol and the dissolution process is diffusion-controlled.Potentiostatic measurements showed that the current density gradually decays to a steady value when the potential is low;however,when the potential is higher than a certain value,the current density initially declines to a minimum value and then increases gradually.The resistance of passive film decreases with increasing potential,and inductive loops are presented when the potential is higher than 2.0 V.展开更多
Anodic dissolutionbehaviorof zirconium inBu^n 4NBr-contaningisopropanol solution was investigated using cyclic voltammetry, linear sweep voltammetry and chronoamperometry, complemented with a scanning electron microsc...Anodic dissolutionbehaviorof zirconium inBu^n 4NBr-contaningisopropanol solution was investigated using cyclic voltammetry, linear sweep voltammetry and chronoamperometry, complemented with a scanning electron microscope （SEM）.The voltammograms did not exhibit active dissolutionuntil the breakdown of passive layer induced by aggressive bromide anions.SEM images confirmed the existence of pits on zirconium surface.The depth and breadth of pits were intensified with increasing potential. The pitting potentialshifted negatively as either temperature orBu^n 4NBr concentration was increased, while it increased with increasing scan rate.The corrosion current density increased with increasing temperature. The apparent activation energyof anodic dissolutionofzirconiumwas 21.88kJ/mol. The chronoamperometry revealed that increasingBu^n 4NBrconcentration shortened the incubation time for passivity breakdown and accelerated the pit nucleation and growth. The experimental results were helpfulto obtain the optimum conditions for electrosynthesis of zirconium isopropoxide.展开更多
基金Research Foundation from National Innovation Center of Advanced Dyeing&Finishing Technology,China(No.2022GCJJ10)。
文摘The development of analytical methods for antibiotic detection has become crucial for public health.In this research,a novel and simple electrochemical sensor for sensitive detection of cefadroxil(CFL)antibiotic was developed.The glassy carbon electrode(GCE)was coated with cheap conductive carbon black VXC-72R that was decorated with tetrabutylammonium tetrafluoroborate(TBABF_(4)),to construct the electrochemical sensor TBABF_(4)/VXC-72R/GCE.It was found that CFL exhibited a reduction peak at approximately 0.22 V on TBABF_(4)/VXC-72R/GCE.TBABF_(4)/VXC-72R/GCE showed a linear response to CFL in a concentration range of 0.3-10.0μmol/L,with a detection limit of 0.2μmol/L(a signal-to-noise ratio of 3).TBABF_(4)/VXC-72R/GCE showed good reproducibility,high storage stability and anti-interference performance.Analytical applications for CFL detection in real lake water,pharmaceutical tablet and fetal bovine serum samples were achieved.
文摘A simple and efficient procedure for the synthesis of 2-arylquinazolin-4（3H）-ones has been developed through cyclocondensation of 2-aminobenzamide with aromatic aldehydes using tetrabutylammonium bromide（TBAB） as novel neutral ionic liquid catalyst in the presence of copper（Ⅱ） chloride（CuCl;） as oxidizing agent under solvent-free conditions at 100℃.In the absence of CuCl;and under a nitrogen atmosphere,the unoxidized intermediates,2-aryl-2,3-dihydroquinazolin-4（1H）-ones,were isolated. Treatment of these intermediates with CuCl;in TBAB media gave the oxidized products 2-arylquinazolin-4（3H）-ones.On the other hand,cyclocondensation of 2-aminobenzamide with aromatic aldehydes in TBAB under microwave irradiation directly gave 2- arylquinazolin-4（3H）-ones.
基金financially supported by the Natural Science Foundation of Henan Province(No.132300410147)
文摘In this article tetrabutylammonium bromide （TBAB） was first added in buffer to compose a convenient and environmentally friendly system, and enzymatic polymerization of phenol catalyzed by horseradish peroxidase （HRP） could proceed efficiently in this system. When TBAB was added, the most conversion of phenol could reach 99.1%. The phenol polymer was considered to consist of a mixture of phenylene （Ph） and oxyphenylene （Ox） units by IR analysis, and the ratio of phenylene to oxyphenylene units （Ph/Ox） was measured by titration. Moreover, the effects of the dosage of horseradish peroxidase （HRP） and pH value on the conversion of phenol were investigated. The reaction performed very effectively in this novel system when the addition of HRP was only 0.2 mg. In all cases, the weight-average molecular weight calculated by GPC-SLS was in a range from 12000 Da to 30000 Da. The phenol polymer prepared in the present research possessed good thermal stability shown by TG analysis.
文摘The title heteropoly blue, (Bu_4N)_6H_(10)[PMo_(11)~ⅥMo~ⅤO_(40)]_4·H_2Ohas been photochemically synthesized and characterized with elemental analysis, solid diffusionreflectance electronic spectra, CV, ESR, XPS, IR spectra, conductivity measurement and X-ray singlecrystal analysis. The crystallographic data for C_(96)H_(218)Mo_(48)N_6O_(169)P_4 are as follows:M_r = 8889.76, triclinic, P_1, a = 1.4142(3) nm, b = 2.6027(5) nm, c = 2.6403(5) nm, α=113.96(3)°, β = 90.05(3)°, γ= 105.71(3)°, V = 8.481(3) nm^3, Z = 1, D_c = 1.741 g/cm^3, F(000)= 4264, μ= 1.798 mm^(-1). The X-ray crystal structure analysis reveals that there is oneindependent molecule in the unit cell of the title heteropoly blue which contains four mixed-valenceheteropoly anions, six tetrabutylammonium cations and one water molecule. Its molecular structurepossesses a centrosymmetrical arrangement in the unit cell. The phosphorus atom is in thecrystallographic inversion center of the heteropoly anion and the eight oxygen atoms surroundingcentral phosphorus atom comprise of a distorted hexahedron. Heteropoly anion has two equal sets ofPO_4 tetrahedron. The PO_4 tetrahedron and the MoO_6 octahedron in the polyanion are greatlydistorted.
基金Project(2007AA03Z425)supported by the Hi-tech Research and Development Program of ChinaProject(50404011)supported by the National Natural Science Foundation of China
文摘The electrochemical behaviors of Ta in tetrabutylammonium hydrogen sulfate（TBAHS） ethanol solutions were studied using potentiodynamic polarization,cyclic voltammetry,potentiostatic current time transient and impedance techniques.The results revealed that no active-passive transition is presented in the cyclic voltammogram,and the anodic current density increases with the increase of solution temperature,TBAHS concentration,potential scan rate and water content.The apparent activation energy is about 43.389 kJ/mol and the dissolution process is diffusion-controlled.Potentiostatic measurements showed that the current density gradually decays to a steady value when the potential is low;however,when the potential is higher than a certain value,the current density initially declines to a minimum value and then increases gradually.The resistance of passive film decreases with increasing potential,and inductive loops are presented when the potential is higher than 2.0 V.
基金Project(51374254)supported by the National Natural Science Foundation of ChinaProject(2013JSJJ026)supported by the Teacher Research Foundation of Central South University,China
文摘Anodic dissolutionbehaviorof zirconium inBu^n 4NBr-contaningisopropanol solution was investigated using cyclic voltammetry, linear sweep voltammetry and chronoamperometry, complemented with a scanning electron microscope （SEM）.The voltammograms did not exhibit active dissolutionuntil the breakdown of passive layer induced by aggressive bromide anions.SEM images confirmed the existence of pits on zirconium surface.The depth and breadth of pits were intensified with increasing potential. The pitting potentialshifted negatively as either temperature orBu^n 4NBr concentration was increased, while it increased with increasing scan rate.The corrosion current density increased with increasing temperature. The apparent activation energyof anodic dissolutionofzirconiumwas 21.88kJ/mol. The chronoamperometry revealed that increasingBu^n 4NBrconcentration shortened the incubation time for passivity breakdown and accelerated the pit nucleation and growth. The experimental results were helpfulto obtain the optimum conditions for electrosynthesis of zirconium isopropoxide.
