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2007 Volume 24 Issue 10
2007, 24(10): 1101-1104
Abstract:
Near-infrared spectra of ethanol solutions were obtained and the mathematic models for quantitative analysis of trace methanol in solution were set up. The mathematic models established by test set-validation and by cross-validation were compared, and the effect of the change of the numbers of samples used in calibration model and validation model of test set-validation on the mathematic models was evaluated. It was found that the predicted results of the mathematic model are good when the number of samples is 15 in calibration model and that in validation model is 6(the total is 21). In that case, the value of the root mean square error of the estimation of calibration and the root mean square error of prediction of validation(RMSEE and RMSEP, respectively) are very small(0.011 5 and 0.010 5 respectively) and almost the same. Our results indicate that near infrared spectroscopy can be used to analyze the content of methanol in ethanol solution very well.
Near-infrared spectra of ethanol solutions were obtained and the mathematic models for quantitative analysis of trace methanol in solution were set up. The mathematic models established by test set-validation and by cross-validation were compared, and the effect of the change of the numbers of samples used in calibration model and validation model of test set-validation on the mathematic models was evaluated. It was found that the predicted results of the mathematic model are good when the number of samples is 15 in calibration model and that in validation model is 6(the total is 21). In that case, the value of the root mean square error of the estimation of calibration and the root mean square error of prediction of validation(RMSEE and RMSEP, respectively) are very small(0.011 5 and 0.010 5 respectively) and almost the same. Our results indicate that near infrared spectroscopy can be used to analyze the content of methanol in ethanol solution very well.
2007, 24(10): 1105-1108
Abstract:
This paper covers the measurement of the abilities of 8 Schiff bases with hydroxyl-substituent to scavenge ABTS+· and DPPH radicals. It was found that the free-radical-scavenging ability of the Schiff bases depends on the amount of the hydroxyl groups. The more hydroxyl group in the Schiff base the better the free-radical-scavenging ability. Moreover, the large conjugation system and the -OH adjacent to the N atom enhanced the ability of the Schiff bases to scavenge ABTS+·. The Schiff base containing a large conjugation system together with an -OH adjacent to the N atom will behave as a strong free-radical-scavenger in trapping DPPH radicals, demonstrating that DPPH is an appropriative agent to detect the free-radical-scavenging property of Schiff bases. In addition, Schiff bases with a larger conjugation system derived from o-aminophenol may be wonderful free-radical-scavengers.
This paper covers the measurement of the abilities of 8 Schiff bases with hydroxyl-substituent to scavenge ABTS+· and DPPH radicals. It was found that the free-radical-scavenging ability of the Schiff bases depends on the amount of the hydroxyl groups. The more hydroxyl group in the Schiff base the better the free-radical-scavenging ability. Moreover, the large conjugation system and the -OH adjacent to the N atom enhanced the ability of the Schiff bases to scavenge ABTS+·. The Schiff base containing a large conjugation system together with an -OH adjacent to the N atom will behave as a strong free-radical-scavenger in trapping DPPH radicals, demonstrating that DPPH is an appropriative agent to detect the free-radical-scavenging property of Schiff bases. In addition, Schiff bases with a larger conjugation system derived from o-aminophenol may be wonderful free-radical-scavengers.
2007, 24(10): 1109-1114
Abstract:
Galactopyranose and glucopyranose with 6-position hydroxyl were conveniently synthesized by selective protection and deprotection of isopropylidene group and benzyl group respectively. Selective benzoylation on 6-position of galactose and glucose could be achieved from the 6-position hydroxyl compounds and then β-aryl C-glycoside intermediates were obtained with high stereoselectivity by means of introducing the glycosyl donors onto 1,4-dimethoxyl benzene. Under moderate oxidation with CAN(ceric ammonium nitrate), 6-O-benzoyl C-glycosyl benzoquinones were prepared and for of them have not been reported. The structures of target compounds were confirmed by 1H NMR, 13C NMR and HRMS spectroscopy. Anti-tumor activity tests including IC50 by MTT tetrazolium dye assay against human melanoma A375 cell line were carried out. The results show that 6-O-benzoyl C-glycosyl benzoquinones possess moderate anti-tumor activity. This character will make them useful in the structure modification and discovery of some potential antitumor with high selectivity and high activity.
Galactopyranose and glucopyranose with 6-position hydroxyl were conveniently synthesized by selective protection and deprotection of isopropylidene group and benzyl group respectively. Selective benzoylation on 6-position of galactose and glucose could be achieved from the 6-position hydroxyl compounds and then β-aryl C-glycoside intermediates were obtained with high stereoselectivity by means of introducing the glycosyl donors onto 1,4-dimethoxyl benzene. Under moderate oxidation with CAN(ceric ammonium nitrate), 6-O-benzoyl C-glycosyl benzoquinones were prepared and for of them have not been reported. The structures of target compounds were confirmed by 1H NMR, 13C NMR and HRMS spectroscopy. Anti-tumor activity tests including IC50 by MTT tetrazolium dye assay against human melanoma A375 cell line were carried out. The results show that 6-O-benzoyl C-glycosyl benzoquinones possess moderate anti-tumor activity. This character will make them useful in the structure modification and discovery of some potential antitumor with high selectivity and high activity.
2007, 24(10): 1115-1118
Abstract:
Triton X-100/n-hexylalcohol/cyclohexane/water inverse microemulsion, 3 inverse microemulsions containing glycin(Gly), arginine(Arg) or histidine(His) were selected as the template to induce the formation of calcium bilirubinate(CaBR) nanoparticles and the effects of amino acids were investigated. CaBRs were characterized by transmission electron microscopy(TEM), Fourier transform infrared spectroscopy(FTIR), ultraviolet-visible spectroscopy(UV-Vis) and zeta potential, respectively. The results show that the global CaBR nano-particles with an average diameter of 80 nm were successfully synthesized in the inverse microemulsion systems, and the stability of suspended CaBR nanoparticles in aqueous solution decreases first and then increases with the increase of solution pH values, and zeta potential absolute value of CaBR particles was 0 mV when the pH of the suspension solution was around 4.9. The addition of each of three hydrophilic amino acids(AAs) is helpful to the nucleation of CaBR and influences the microstructure, morphology and agglomeration of CaBR. Global CaBR nanoparticles also formed successfully in the microemlulsion and the stability of the aqueous suspended nanoparticles increased with the addition of His or Gly, but the average diameters of them reduced to 60 nm or 40 nm, respectively. Irregular CaBR nanoparticles with the smallest diameter were produced in inverse microemulsion containing Arg and were easy to agglomerate in aqueous suspended solution.
Triton X-100/n-hexylalcohol/cyclohexane/water inverse microemulsion, 3 inverse microemulsions containing glycin(Gly), arginine(Arg) or histidine(His) were selected as the template to induce the formation of calcium bilirubinate(CaBR) nanoparticles and the effects of amino acids were investigated. CaBRs were characterized by transmission electron microscopy(TEM), Fourier transform infrared spectroscopy(FTIR), ultraviolet-visible spectroscopy(UV-Vis) and zeta potential, respectively. The results show that the global CaBR nano-particles with an average diameter of 80 nm were successfully synthesized in the inverse microemulsion systems, and the stability of suspended CaBR nanoparticles in aqueous solution decreases first and then increases with the increase of solution pH values, and zeta potential absolute value of CaBR particles was 0 mV when the pH of the suspension solution was around 4.9. The addition of each of three hydrophilic amino acids(AAs) is helpful to the nucleation of CaBR and influences the microstructure, morphology and agglomeration of CaBR. Global CaBR nanoparticles also formed successfully in the microemlulsion and the stability of the aqueous suspended nanoparticles increased with the addition of His or Gly, but the average diameters of them reduced to 60 nm or 40 nm, respectively. Irregular CaBR nanoparticles with the smallest diameter were produced in inverse microemulsion containing Arg and were easy to agglomerate in aqueous suspended solution.
2007, 24(10): 1119-1123
Abstract:
Five 2,5-diaryl-1,3,4-oxadiazole derivatives used as a new class of cyclometlating ligands were synthsized. Their molecular structures were characterized by IR, 1H NMR and element analysis. Furthermore, their spectroscopic, thermal and electrochemical properties were investigated by UV spectroscopy, fluorescence spectroscopy, differential scanning calorimetry(DSC) and cyclic voltammetry(CV), respectively. The results showed that the maximum UV absorption wavelengths of those 1,3,4-oxadiazole derivatives in dichloromethane were in the range of 268~327 nm, and their maximum photoluminescent wavelengths in dichloromethane and solid film were located at 332~390 nm and 359~439 nm, respectively. The 1,3,4-oxadiazole derivatives exhibit a first endothermal peak at 120~328℃ in the DSC heating process, and the symmetrical 1,3,4-oxadiazole derivatives display a higher melting temperature. The CV curves of those 1,3,4-oxadiazole derivatives indicate that the reductive potentials of the 1,3,4-oxadiazole derivatives are located at -1.03~-0.98 V, and their LUMO(the lowest unoccoupied molecual orbit) energy levels are -3.71~-3.76 eV.
Five 2,5-diaryl-1,3,4-oxadiazole derivatives used as a new class of cyclometlating ligands were synthsized. Their molecular structures were characterized by IR, 1H NMR and element analysis. Furthermore, their spectroscopic, thermal and electrochemical properties were investigated by UV spectroscopy, fluorescence spectroscopy, differential scanning calorimetry(DSC) and cyclic voltammetry(CV), respectively. The results showed that the maximum UV absorption wavelengths of those 1,3,4-oxadiazole derivatives in dichloromethane were in the range of 268~327 nm, and their maximum photoluminescent wavelengths in dichloromethane and solid film were located at 332~390 nm and 359~439 nm, respectively. The 1,3,4-oxadiazole derivatives exhibit a first endothermal peak at 120~328℃ in the DSC heating process, and the symmetrical 1,3,4-oxadiazole derivatives display a higher melting temperature. The CV curves of those 1,3,4-oxadiazole derivatives indicate that the reductive potentials of the 1,3,4-oxadiazole derivatives are located at -1.03~-0.98 V, and their LUMO(the lowest unoccoupied molecual orbit) energy levels are -3.71~-3.76 eV.
2007, 24(10): 1124-1127
Abstract:
Diorganotin(Ⅳ) compound[Ph2Sn(C9H7N3O3)-(H2O)]2 was synthesized from the reaction of Ph2SnO with Schiff base ligand pyruvic acid isonicotinyl hydrazone. The compound was characterized by elemental analysis, IR, and 1H NMR, and the crystal structure was determined by X-ray single crystal diffraction. The crystal belongs to the orthorhombic system with space group P212121c, with a=1.142 0(3) nm, b=1.171 3(8) nm, c=3.520(2) nm, V=4.709(5) nm3, Z=4, μ=1.125 mm-1, Dc=1.501 Mg/m3, F(000)=2 144, R=0.074 5, wR=0.170 4, GOF=1.015. In this molecule, the Sn atom exists in a distorted pentagonal bipyramidal coordination environment in which one water molecule, one tridentate pyruvic acid isonicotinyl hydrazone ligand, and two trans P-cyanobenzyl groups coordinate to each Sn center, and the angle of the axial C10-Sn1-C18 is 166.1(2)°. The antitumor activity tests for the human tumor cell lines MCF-7 and WiDr show that this complex exhibits a good bioactivity.
Diorganotin(Ⅳ) compound[Ph2Sn(C9H7N3O3)-(H2O)]2 was synthesized from the reaction of Ph2SnO with Schiff base ligand pyruvic acid isonicotinyl hydrazone. The compound was characterized by elemental analysis, IR, and 1H NMR, and the crystal structure was determined by X-ray single crystal diffraction. The crystal belongs to the orthorhombic system with space group P212121c, with a=1.142 0(3) nm, b=1.171 3(8) nm, c=3.520(2) nm, V=4.709(5) nm3, Z=4, μ=1.125 mm-1, Dc=1.501 Mg/m3, F(000)=2 144, R=0.074 5, wR=0.170 4, GOF=1.015. In this molecule, the Sn atom exists in a distorted pentagonal bipyramidal coordination environment in which one water molecule, one tridentate pyruvic acid isonicotinyl hydrazone ligand, and two trans P-cyanobenzyl groups coordinate to each Sn center, and the angle of the axial C10-Sn1-C18 is 166.1(2)°. The antitumor activity tests for the human tumor cell lines MCF-7 and WiDr show that this complex exhibits a good bioactivity.
2007, 24(10): 1128-1131
Abstract:
A fluorine-containing polyimide was synthesized from 1,3-bis(4-aminophenoxy)benzene (1,3-BPA), 4,4'-(hexafluoroisopropylidene)diphthalic anhydride(6FDA) and dispersed red 1(DR1). The thermal properties and structure of the polymer were characterized by differential scanning calorimetry(DSC), thermal gravimetric analysis(TGA), UV-Vis and FT-IR. The glass transition temperature(Tg) and the temperature at which 5% mass loss of polyimide occurred were 238 and 287℃, respectively. The material has good thermal stability. The dn/dT and dβ/dT were -2.31×10-4~-3.04×10-4 and 2.56×10-7~4.32×10-7(different concentration, natural light), -3.08×10-4 and 4.72×10-7(436 nm)/℃, respectively. The compound may be used in new digital optical switches with low driving power and optical communication devices.
A fluorine-containing polyimide was synthesized from 1,3-bis(4-aminophenoxy)benzene (1,3-BPA), 4,4'-(hexafluoroisopropylidene)diphthalic anhydride(6FDA) and dispersed red 1(DR1). The thermal properties and structure of the polymer were characterized by differential scanning calorimetry(DSC), thermal gravimetric analysis(TGA), UV-Vis and FT-IR. The glass transition temperature(Tg) and the temperature at which 5% mass loss of polyimide occurred were 238 and 287℃, respectively. The material has good thermal stability. The dn/dT and dβ/dT were -2.31×10-4~-3.04×10-4 and 2.56×10-7~4.32×10-7(different concentration, natural light), -3.08×10-4 and 4.72×10-7(436 nm)/℃, respectively. The compound may be used in new digital optical switches with low driving power and optical communication devices.
2007, 24(10): 1132-1135
Abstract:
The nucleation and crystal growth of calcium bilirubinate crystalls in four different aqueous biomi-metic systems were studied by FT-IR, XRD, SEM and TGA, and the effect of biomacromolecules and CO2 on the crystal nucleation of the calcium bilirubinate was investigated. The results indicated that the calcium bilirubinate crystals couldn't form spontaneously in the aqueous solution, while multiple crystals of calcium bilirubinate and calcium calcite coexisted and the mass content of the calcium calcite was about 12%. In the course of the nucleation and growth of the multiple crystals, crystal calcium bilirubinate with two obvious X-diffraction peaks at 2θ 19.8° and 21.8° were induced by the dextran and the calcite crystal formed under the effect of CO2 in the air. In the process, proper sites for the nucleation of calcium bilirubinate were provided by the crystal surface of the calcium calcite and the oxygenous function of the dextran molecules due to the effect on the coordination between the Ca2+ ions and the bilirubin, and the growth of the crystal calcium bilirubinate with a distinct decomposition temperature was induced.
The nucleation and crystal growth of calcium bilirubinate crystalls in four different aqueous biomi-metic systems were studied by FT-IR, XRD, SEM and TGA, and the effect of biomacromolecules and CO2 on the crystal nucleation of the calcium bilirubinate was investigated. The results indicated that the calcium bilirubinate crystals couldn't form spontaneously in the aqueous solution, while multiple crystals of calcium bilirubinate and calcium calcite coexisted and the mass content of the calcium calcite was about 12%. In the course of the nucleation and growth of the multiple crystals, crystal calcium bilirubinate with two obvious X-diffraction peaks at 2θ 19.8° and 21.8° were induced by the dextran and the calcite crystal formed under the effect of CO2 in the air. In the process, proper sites for the nucleation of calcium bilirubinate were provided by the crystal surface of the calcium calcite and the oxygenous function of the dextran molecules due to the effect on the coordination between the Ca2+ ions and the bilirubin, and the growth of the crystal calcium bilirubinate with a distinct decomposition temperature was induced.
2007, 24(10): 1136-1139
Abstract:
The catalytic system of sulfuric acid-water-copper used in Ullmann condensation reaction of bromamine acid was replaced with a strong acid ion exchange resin-ethanol-copper system. The effect of the ion exchange resin loading, the kind of solvent, and the reaction temperature on the yield of the condensation product was investigated. The results show that the yield of the condensation product could reach 94.0% in ethanol-water(9:1) at 70℃ after 3 h. The strong acid ion exchange resin, copper powder and ethanol could be reused under the reaction conditions. The activity of the resin was not obviously reduced after reusing 5 times, and 70%~80% ethanol and 85%~90% copper powder in the reaction can be recovered.
The catalytic system of sulfuric acid-water-copper used in Ullmann condensation reaction of bromamine acid was replaced with a strong acid ion exchange resin-ethanol-copper system. The effect of the ion exchange resin loading, the kind of solvent, and the reaction temperature on the yield of the condensation product was investigated. The results show that the yield of the condensation product could reach 94.0% in ethanol-water(9:1) at 70℃ after 3 h. The strong acid ion exchange resin, copper powder and ethanol could be reused under the reaction conditions. The activity of the resin was not obviously reduced after reusing 5 times, and 70%~80% ethanol and 85%~90% copper powder in the reaction can be recovered.
2007, 24(10): 1140-1144
Abstract:
The electrochemical behavior of Malachite green(MG) in the micellar solution of Cetylyrldinium bromide(CPB) was studied by cyclic voltammetry(CV) at GCE, and also compared with that in PBS. At scan rates of 20~300 mV/s, the peak current(Ip) varies with the square root of the scan rate, which shows the electrochemical oxidation of MG is a diffusion-controlled electrode process. The influence of solution pH on the oxidation peak current(Ip) and peak potential(Ep) for MG was studied in a pH range of 2.0 to 8.0. It was found that MG was oxidized with no proton participation in the electrode process between pH 4 to 8. The electrochemical kinetic parameters of MG with and without CPB micellar solution were determined by chronocoulometry(CC) and chronoamperometry(CA). Diffusion coefficient D, electron transfer coefficient α, and the electrode reaction rate constant Kf were 2.34×10-6 cm2/s and 2.51×10-6 cm2/s, 0.56 and 0.72, and 3.95×10-4 s-1 and 9.12×10-4 s-1, respectively. Also the influence of PBS and MG concentration on the interaction of CPB and MG were studied and a reasonable explanation was given. It was found that the critical micelle concentration(CMC) of CPB was reached earlier and the plateau of the oxidation peak current was lower at high concentration of PBS. With the increasing of the MG concentration, the oxidation peak potential shifted positively and the peak current decreased with the MG concentration in the range of 2.0×10-2~8 mmol/L.
The electrochemical behavior of Malachite green(MG) in the micellar solution of Cetylyrldinium bromide(CPB) was studied by cyclic voltammetry(CV) at GCE, and also compared with that in PBS. At scan rates of 20~300 mV/s, the peak current(Ip) varies with the square root of the scan rate, which shows the electrochemical oxidation of MG is a diffusion-controlled electrode process. The influence of solution pH on the oxidation peak current(Ip) and peak potential(Ep) for MG was studied in a pH range of 2.0 to 8.0. It was found that MG was oxidized with no proton participation in the electrode process between pH 4 to 8. The electrochemical kinetic parameters of MG with and without CPB micellar solution were determined by chronocoulometry(CC) and chronoamperometry(CA). Diffusion coefficient D, electron transfer coefficient α, and the electrode reaction rate constant Kf were 2.34×10-6 cm2/s and 2.51×10-6 cm2/s, 0.56 and 0.72, and 3.95×10-4 s-1 and 9.12×10-4 s-1, respectively. Also the influence of PBS and MG concentration on the interaction of CPB and MG were studied and a reasonable explanation was given. It was found that the critical micelle concentration(CMC) of CPB was reached earlier and the plateau of the oxidation peak current was lower at high concentration of PBS. With the increasing of the MG concentration, the oxidation peak potential shifted positively and the peak current decreased with the MG concentration in the range of 2.0×10-2~8 mmol/L.
2007, 24(10): 1145-1148
Abstract:
Eight novel N,N'-naphthalene acyl substituted aromatic acylamino thiocarbamides(Ⅱ1~Ⅱ8) were synthesized from aryl acylhydrazine(Ⅰ) and α-naphthalene acyl isothiocyanate, which was obtained by the reaction of potassium thiocyanate with α-naphthalene acyl chloride obtained from 2-naphthylacetic acid and thionyl chloride in anhydrous benzene. The structures of the products were characterized by IR,1H NMR and elemental analysis. The preliminary biological activity test indicated that the synthesized compounds could promote the growth of paddy root with best effect at 1 mg/L, but had no obvious inhibition activity against B.subtiles and E.coli.
Eight novel N,N'-naphthalene acyl substituted aromatic acylamino thiocarbamides(Ⅱ1~Ⅱ8) were synthesized from aryl acylhydrazine(Ⅰ) and α-naphthalene acyl isothiocyanate, which was obtained by the reaction of potassium thiocyanate with α-naphthalene acyl chloride obtained from 2-naphthylacetic acid and thionyl chloride in anhydrous benzene. The structures of the products were characterized by IR,1H NMR and elemental analysis. The preliminary biological activity test indicated that the synthesized compounds could promote the growth of paddy root with best effect at 1 mg/L, but had no obvious inhibition activity against B.subtiles and E.coli.
2007, 24(10): 1149-1152
Abstract:
Transesterification of rape oil and methanol to prepare biodiesel with solid base CaO/MgO as the catalyst was studied.The catalyst was prepared by impregnation and had a high catalysis activity. Effect of the catalyst preparation conditions and the transesterification reaction conditions was investigated. The experiment showed that the optimum conditions of catalyst preparation were that the molar ratio of CaO to MgO was 1.0:5.44, the calcination temperature and the calcination time were 700℃ and 24 h respectively. The suitable conditions of transesterification were also obtained, where the molar ratio of methanol to oil was 6:1, the loading of the catalyst CaO/MgO was 3% of the oil weight, and the reaction temperature and reaction time was 70℃ and 4 h respectively. Under those conditions, the conversion of the oil was more than 98% and the biodiesel produced met the Austria DIN V 51 standard.
Transesterification of rape oil and methanol to prepare biodiesel with solid base CaO/MgO as the catalyst was studied.The catalyst was prepared by impregnation and had a high catalysis activity. Effect of the catalyst preparation conditions and the transesterification reaction conditions was investigated. The experiment showed that the optimum conditions of catalyst preparation were that the molar ratio of CaO to MgO was 1.0:5.44, the calcination temperature and the calcination time were 700℃ and 24 h respectively. The suitable conditions of transesterification were also obtained, where the molar ratio of methanol to oil was 6:1, the loading of the catalyst CaO/MgO was 3% of the oil weight, and the reaction temperature and reaction time was 70℃ and 4 h respectively. Under those conditions, the conversion of the oil was more than 98% and the biodiesel produced met the Austria DIN V 51 standard.
2007, 24(10): 1153-1156
Abstract:
Via near infrared(NIR) spectroscopy combined with radial basis function neural network(RBFNN), a model for determining pyrazinamide(PZA) content in tablets was established. Leave-one-cross-validation method was used for selecting the most effective preprocessing method, the most suitable topological parameters and the best spread constant in the RBFNN. The results showed that Savitzky-Golay smoothing method was the most effective preprocessing method, and the most suitable number of input nodes and hidden nodes were 8 and 15 respectively, and the best spread constant was 2.5. The optimum parameters were applied to establish the model for determining the pyrazinamide content in tablets with the root mean squares error cross-validation(RMSECV) of 0.005 52. Using this model for determining the pyrazinamide content in the prediction set, the root mean squares error of prediction set(RMSEP) was 0.003 30 and the average recovery was 100.091%. NIR method and UV-spectroscopy method were used for determining the pyrazinamide content in 6 different batches of Pyrazinamide tablets respectively, and the relative error between the values obtained by these methods was less than 4.179%. These results demonstrate that the NIR method is precise, convenient, and rapid, and involves no pretreatment and pollution, and may have extensive application in pharmaceutics quantitative analysis.
Via near infrared(NIR) spectroscopy combined with radial basis function neural network(RBFNN), a model for determining pyrazinamide(PZA) content in tablets was established. Leave-one-cross-validation method was used for selecting the most effective preprocessing method, the most suitable topological parameters and the best spread constant in the RBFNN. The results showed that Savitzky-Golay smoothing method was the most effective preprocessing method, and the most suitable number of input nodes and hidden nodes were 8 and 15 respectively, and the best spread constant was 2.5. The optimum parameters were applied to establish the model for determining the pyrazinamide content in tablets with the root mean squares error cross-validation(RMSECV) of 0.005 52. Using this model for determining the pyrazinamide content in the prediction set, the root mean squares error of prediction set(RMSEP) was 0.003 30 and the average recovery was 100.091%. NIR method and UV-spectroscopy method were used for determining the pyrazinamide content in 6 different batches of Pyrazinamide tablets respectively, and the relative error between the values obtained by these methods was less than 4.179%. These results demonstrate that the NIR method is precise, convenient, and rapid, and involves no pretreatment and pollution, and may have extensive application in pharmaceutics quantitative analysis.
2007, 24(10): 1157-1161
Abstract:
A series of polymer complexes of Eu-Tb with α-thenoyltrifluoroacetone(HTTA) and 5-sulfoalieylic acid(SSAH2) as micro molecule ligand and copolymer of acrylic acid and methylmethacrylate as polymer ligand was synthesized. The complexes were characterized by means of elemental analysis, ultraviolet and infrared spectroscopies. Their fluorescence properties and the mutual effect on the fluorescence properties of europium and terbium were investigated Via the fluorescence spectroscopy. The fluorescent emission peak location and the relationships between the fluorescent emission intensity and composition were also discussed. The results show that the fluorescent intensity has a sensitize or quench effect between Eu3+ and Tb3+ in the rare-earth(Eu,Tb) polynuclear polymer fluorescence complexes. Eu3+ ions shows a strong luminescence quenching effect on Tb3+ ions, and this effect is the strongest when the n(Eu3+):n(Tb3+) is 1:1. When Tb3+ ion concentration is low (n(Eu3+):n(Tb3+) is greater than 1:1), Tb3+ ions exhibit a luminescence quenching effect on Eu3+ ions; when Tb3+ ion concentration is high(n(Eu3+):n(Tb3+) is less than 1:1), Tb3+ ions display a very strong sensitization effect on Eu3+ ions.
A series of polymer complexes of Eu-Tb with α-thenoyltrifluoroacetone(HTTA) and 5-sulfoalieylic acid(SSAH2) as micro molecule ligand and copolymer of acrylic acid and methylmethacrylate as polymer ligand was synthesized. The complexes were characterized by means of elemental analysis, ultraviolet and infrared spectroscopies. Their fluorescence properties and the mutual effect on the fluorescence properties of europium and terbium were investigated Via the fluorescence spectroscopy. The fluorescent emission peak location and the relationships between the fluorescent emission intensity and composition were also discussed. The results show that the fluorescent intensity has a sensitize or quench effect between Eu3+ and Tb3+ in the rare-earth(Eu,Tb) polynuclear polymer fluorescence complexes. Eu3+ ions shows a strong luminescence quenching effect on Tb3+ ions, and this effect is the strongest when the n(Eu3+):n(Tb3+) is 1:1. When Tb3+ ion concentration is low (n(Eu3+):n(Tb3+) is greater than 1:1), Tb3+ ions exhibit a luminescence quenching effect on Eu3+ ions; when Tb3+ ion concentration is high(n(Eu3+):n(Tb3+) is less than 1:1), Tb3+ ions display a very strong sensitization effect on Eu3+ ions.
2007, 24(10): 1162-1166
Abstract:
4-(2-Chlorophenyl)but-3-en-2-one was prepared Via the condensation of 2-chlorobenzaldehyde and acetone followed by cyclization with hydrazine monohydrate. Eighteen new 5-(2-hydroxyphenyl)-3-methyl(or ethyl)-4,5-dihydro-N-acylpyrazole derivatives were synthesized and characterized by elemental analysis, IR and 1H NMR. The experimental results show the inhibition rate of compound 3ae against P.oryzae was up to 60.2%, the inhibition rate of compound 3bf against S.Sclerotiorum was up to 56.7%. Conpounds 3aj and 3bj exhibited certain fungicidal activity against H.Oryzae, P.oryza, S.Sclerotiorum, with inhibition rate of up to 50%.
4-(2-Chlorophenyl)but-3-en-2-one was prepared Via the condensation of 2-chlorobenzaldehyde and acetone followed by cyclization with hydrazine monohydrate. Eighteen new 5-(2-hydroxyphenyl)-3-methyl(or ethyl)-4,5-dihydro-N-acylpyrazole derivatives were synthesized and characterized by elemental analysis, IR and 1H NMR. The experimental results show the inhibition rate of compound 3ae against P.oryzae was up to 60.2%, the inhibition rate of compound 3bf against S.Sclerotiorum was up to 56.7%. Conpounds 3aj and 3bj exhibited certain fungicidal activity against H.Oryzae, P.oryza, S.Sclerotiorum, with inhibition rate of up to 50%.
2007, 24(10): 1167-1171
Abstract:
The interaction mechanism of diethylmalonylurea(BBT) with bovine serum albumin(BSA) was studied by fluorescence and UV-Vis spectra. It is shown that BBT has a powerful ability to quench the fluorescence intensity of BSA. The fluorescence quenching data were analyzed according to Stern-Volmer equation and Line weaver-Burk equation at 17℃ and 37℃ to obtain the quenching constants, 17℃KSV=1.427×104 and 37℃KSV=1.195×104, 17℃KLB=9.848×103 and 37℃KLB=1.778×103, and the binding constant K0=4.341×104, and the thermodynamic parameters(ΔH, ΔS and ΔG). It was deduced that combining site n was 1.136. The increasing of temperature was favorable for the BBT-BSA interaction. According to the thermodynamic parameters, the major binding forces were determined. The effect of BBT on the conformation of BSA was analyzed Via synchronous fluorescence spectroscopy.
The interaction mechanism of diethylmalonylurea(BBT) with bovine serum albumin(BSA) was studied by fluorescence and UV-Vis spectra. It is shown that BBT has a powerful ability to quench the fluorescence intensity of BSA. The fluorescence quenching data were analyzed according to Stern-Volmer equation and Line weaver-Burk equation at 17℃ and 37℃ to obtain the quenching constants, 17℃KSV=1.427×104 and 37℃KSV=1.195×104, 17℃KLB=9.848×103 and 37℃KLB=1.778×103, and the binding constant K0=4.341×104, and the thermodynamic parameters(ΔH, ΔS and ΔG). It was deduced that combining site n was 1.136. The increasing of temperature was favorable for the BBT-BSA interaction. According to the thermodynamic parameters, the major binding forces were determined. The effect of BBT on the conformation of BSA was analyzed Via synchronous fluorescence spectroscopy.
2007, 24(10): 1172-1176
Abstract:
The novel soluble polyester-urethane-imide block copolymers containing carboxyl structure were synthesized successfully by four steps of synthesis reaction. Phthalic carboxyl monoester diols(PCMD) were synthesized by the high-pressure solvent-heat reaction of 1,1,1-trimethylolpropane(TMP) with phthalic anhydride(PA) at a molar ratio of 1:1. Then the hydroxyl-terminated polyester with phthalic carboxyl(Mn ca. 2 192) was prepared by the condensation reaction of monomer PCMD and hexanedioic acid at a molar ratio of 6:5. The NCO-terminated polyurethane prepolymers were formed from the reaction of polyester diols with phthalic carboxyl and tolylene-2, 4-Diisocyanate(TDI) or with methylenedi-p-phenyl diisocyanate(MDI) at a molar ratio of 1:2, respectively. Finally, the soluble polyuethane-imide block copolymers were synthesized by the chain extending reaction and imidization of the PU prepolymer with 1,2,4,5-benzenetetracarboxylic dianhydride(PMDA) at a molar ratio of 1:1 and 60℃ for 48 h. The reaction processes were controlled by titration analysis and traced by FT-IR. The in-process products and the polyester-urethane-imide block copolymers were characterized by 1H NMR and FTIR. The solubility of the products was tested.
The novel soluble polyester-urethane-imide block copolymers containing carboxyl structure were synthesized successfully by four steps of synthesis reaction. Phthalic carboxyl monoester diols(PCMD) were synthesized by the high-pressure solvent-heat reaction of 1,1,1-trimethylolpropane(TMP) with phthalic anhydride(PA) at a molar ratio of 1:1. Then the hydroxyl-terminated polyester with phthalic carboxyl(Mn ca. 2 192) was prepared by the condensation reaction of monomer PCMD and hexanedioic acid at a molar ratio of 6:5. The NCO-terminated polyurethane prepolymers were formed from the reaction of polyester diols with phthalic carboxyl and tolylene-2, 4-Diisocyanate(TDI) or with methylenedi-p-phenyl diisocyanate(MDI) at a molar ratio of 1:2, respectively. Finally, the soluble polyuethane-imide block copolymers were synthesized by the chain extending reaction and imidization of the PU prepolymer with 1,2,4,5-benzenetetracarboxylic dianhydride(PMDA) at a molar ratio of 1:1 and 60℃ for 48 h. The reaction processes were controlled by titration analysis and traced by FT-IR. The in-process products and the polyester-urethane-imide block copolymers were characterized by 1H NMR and FTIR. The solubility of the products was tested.
2007, 24(10): 1177-1181
Abstract:
The epoxidation reaction of soybean oil with 30% hydrogen peroxide and a heteropolyphosphotungstate salt as reaction-controlled phase transfer catalyst, and 1,2-dichloroethane as the solvent under neutral condition was studied. The optimized reaction conditions were 3%(mass fraction) catalyst, molar ratio of H2O2 and soybean oil 1.2:1, mass ratio of solvent and soybean oil 3.2:1, reaction temperature 70℃, and reaction time 4 h. Under the above mentioned conditions, the epoxy value was higher than 6%, and the iodine value was less than 0.04 g(I)/g. The catalyst was recycled five times without losing catalyst activity, showing excellent reaction controlled phase transfer catalyst property.
The epoxidation reaction of soybean oil with 30% hydrogen peroxide and a heteropolyphosphotungstate salt as reaction-controlled phase transfer catalyst, and 1,2-dichloroethane as the solvent under neutral condition was studied. The optimized reaction conditions were 3%(mass fraction) catalyst, molar ratio of H2O2 and soybean oil 1.2:1, mass ratio of solvent and soybean oil 3.2:1, reaction temperature 70℃, and reaction time 4 h. Under the above mentioned conditions, the epoxy value was higher than 6%, and the iodine value was less than 0.04 g(I)/g. The catalyst was recycled five times without losing catalyst activity, showing excellent reaction controlled phase transfer catalyst property.
2007, 24(10): 1182-1186
Abstract:
Single magnetic domain hexagonal barium ferrite BaFe12O19 particles were synthesized at 850℃ Via Sol-Gel technique. The structure, magnetic properties and morphorlogy of the particles were characterized by X-ray diffraction, vibrating sample magnetometer and scanning electron microscopy. The effect of temperature and heating time on the structure, magnetic properties and morphorlogy of the particles was studied. Higher heating rates favored the formation of plate-like particles. With the increase of the heating time and the heating temperature, the hexagonal barium ferrite BaFe12O19 particles were more uniform, and the crystallinity was more perfect, and the size of the particles increased. Owing to the single magnetic domain of the particles, the specific saturated magnetization and the coercivity were enhanced with the increase of the heating time and the heating temperature. The specific saturated magnetization was 53 A·m2/kg and the coercivity was 277.6×03 A/m for the sample calcined at 850℃ for 4 h. In comparison, the sample calcined at 1 000℃ for 4 h exhibited a specific saturated magnetization of 59 A·m2/kg and a coercivity of 353.3×103 A/m. For the samples calcined at 850℃, with the heating time increasing, the specific saturated magnetization increased from 48 A·m2/kg to 56 A·m2/kg, and the coercivities also increased form 211.5×103 A/m to 357.1×103 A/m.
Single magnetic domain hexagonal barium ferrite BaFe12O19 particles were synthesized at 850℃ Via Sol-Gel technique. The structure, magnetic properties and morphorlogy of the particles were characterized by X-ray diffraction, vibrating sample magnetometer and scanning electron microscopy. The effect of temperature and heating time on the structure, magnetic properties and morphorlogy of the particles was studied. Higher heating rates favored the formation of plate-like particles. With the increase of the heating time and the heating temperature, the hexagonal barium ferrite BaFe12O19 particles were more uniform, and the crystallinity was more perfect, and the size of the particles increased. Owing to the single magnetic domain of the particles, the specific saturated magnetization and the coercivity were enhanced with the increase of the heating time and the heating temperature. The specific saturated magnetization was 53 A·m2/kg and the coercivity was 277.6×03 A/m for the sample calcined at 850℃ for 4 h. In comparison, the sample calcined at 1 000℃ for 4 h exhibited a specific saturated magnetization of 59 A·m2/kg and a coercivity of 353.3×103 A/m. For the samples calcined at 850℃, with the heating time increasing, the specific saturated magnetization increased from 48 A·m2/kg to 56 A·m2/kg, and the coercivities also increased form 211.5×103 A/m to 357.1×103 A/m.
2007, 24(10): 1187-1192
Abstract:
Metallic vanadyl porphyrins were isolated from LGAR and its components Via improved solvent extraction. 18.5% of vanadium in LGAR, 68.0% of vanadium in LGAR maltene and 9.2% of vanadium in LGAR asphaltene were isolated by this method. The vanadyl porphyrin and base porphyrin were characterized by UV-Vis spectrophotometry, and the vanadyl porphyrin in LGAR was mainly ETIO, which was confirmed by matrix assisted laser desorption ionization time of flight mass spectroscopy(MALDI-TOF MS) of base porphyrin.
Metallic vanadyl porphyrins were isolated from LGAR and its components Via improved solvent extraction. 18.5% of vanadium in LGAR, 68.0% of vanadium in LGAR maltene and 9.2% of vanadium in LGAR asphaltene were isolated by this method. The vanadyl porphyrin and base porphyrin were characterized by UV-Vis spectrophotometry, and the vanadyl porphyrin in LGAR was mainly ETIO, which was confirmed by matrix assisted laser desorption ionization time of flight mass spectroscopy(MALDI-TOF MS) of base porphyrin.
2007, 24(10): 1193-1196
Abstract:
Five novel aryl acrylates were synthesized from Baylis-Hillman adducts according to the principle of combination of bioactive substructures. Their structures were confirmed by IR, 1H NMR and elemental analysis. Preliminary bioactivities of these new compounds were evaluated in the green house. The result indicates that the target compounds have no insecticidal activity at 600 g a.i./hm2 and no fungicidal activity at 400 g a.i./hm2. The target compounds show certain herbicidal activity against Zinnia elegans Jacq., Abutilon theophrasti Medic., Echinochloa crusgalli(L.) Baeuv. and Digitaria sanguinalis (L.) Scop at 2 000 g a.i./hm2. These compounds are brand new and contain versatile multifunctional molecules that could easily be modified and used as lead compounds for further study.
Five novel aryl acrylates were synthesized from Baylis-Hillman adducts according to the principle of combination of bioactive substructures. Their structures were confirmed by IR, 1H NMR and elemental analysis. Preliminary bioactivities of these new compounds were evaluated in the green house. The result indicates that the target compounds have no insecticidal activity at 600 g a.i./hm2 and no fungicidal activity at 400 g a.i./hm2. The target compounds show certain herbicidal activity against Zinnia elegans Jacq., Abutilon theophrasti Medic., Echinochloa crusgalli(L.) Baeuv. and Digitaria sanguinalis (L.) Scop at 2 000 g a.i./hm2. These compounds are brand new and contain versatile multifunctional molecules that could easily be modified and used as lead compounds for further study.
2007, 24(10): 1197-1200
Abstract:
Poly(methyl methacrylate)(PMMA) was grafted onto poly(vinylidine fluoride)(PVDF) films pre-irradiated electron beam(EB). The influence of the radiation dosage, monomer concentration, reaction temperature and time as well as solvent on the grafting reaction was studied. Results showed that grafting rate increased with the radiation doseage. With the increase of monomer concentration, the grafting rate increased quickly at the preliminary stage and increased slowly above 40% and then reached a maximum when the monomer concentration was 70%. Grafting rate increased slowly below 40℃, and increased fast at 60℃, and then remained unchanged. Alcohols were effective solvents for the graft polymerization. The composition of the grafted film was analyzed using FT-IR, and the thermal performance of the grafted film was characterized by DSC. The FT-IR showed that the grafted film was a PVDF-g-PMMA copolymer. A thermal transition appeared at 117℃ and became more marked with the grafting yield. The melting peak moved to the left and disappeared finally with the grafting rate, which proved the grafting of PMMA broke down the PVDF film's crystallinity. At the DOG of 50%, the liquid uptake volume was 290% and the conductivity was 6.0×10-3 S/cm.
Poly(methyl methacrylate)(PMMA) was grafted onto poly(vinylidine fluoride)(PVDF) films pre-irradiated electron beam(EB). The influence of the radiation dosage, monomer concentration, reaction temperature and time as well as solvent on the grafting reaction was studied. Results showed that grafting rate increased with the radiation doseage. With the increase of monomer concentration, the grafting rate increased quickly at the preliminary stage and increased slowly above 40% and then reached a maximum when the monomer concentration was 70%. Grafting rate increased slowly below 40℃, and increased fast at 60℃, and then remained unchanged. Alcohols were effective solvents for the graft polymerization. The composition of the grafted film was analyzed using FT-IR, and the thermal performance of the grafted film was characterized by DSC. The FT-IR showed that the grafted film was a PVDF-g-PMMA copolymer. A thermal transition appeared at 117℃ and became more marked with the grafting yield. The melting peak moved to the left and disappeared finally with the grafting rate, which proved the grafting of PMMA broke down the PVDF film's crystallinity. At the DOG of 50%, the liquid uptake volume was 290% and the conductivity was 6.0×10-3 S/cm.
2007, 24(10): 1201-1205
Abstract:
The influence of temperature on encapsulation of various guest mercaptans in β-cyclodextrin(β-CD) was investigated by the competitive UV-Vis spectrophotometric method. The results indicated that β-CD could include different mercaptans to form inclusion compounds at different temperatures. The inclusion stability constants of β-CD including 1-butanethiol at 25.0, 30.0, 35.0, 40.0 and 50.0℃, were 49.37, 66.39, 93.88, 124.5, and 197.61 L/mol, respectively, and those of β-CD wrapping 2-methyl-1-propanethiol were 326.0, 364.6, 415.3, 472.2, and 592.4 L/mol, respectively. The thermodynamic parameters ΔG, ΔH, and ΔS of the inclusion process were -9.661 kJ/mol, 35.85 kJ/mol, and 152.63 J/(mol·K) for 1-butanethiol, and -14.34 kJ/mol, 19.35 kJ/mol, and 112.98 J/(mol·K) for 2-methyl-1-propanethiol, respectively. It was found that the inclusion abilities of β-CD encapsulating various mercaptans were all enhanced with the increase of temperature; β-CD could spontaneously include various mercaptans in the temperature range studied, and the inclusion process was endothermic and controlled by entropy. The outer water shell of the hydrophobic alkyl of the mercaptan was destroged, causing the increase of the number of free molecules and the increase of the degree of freedom for the hydrophobic alkyl of the mercaptan inserted into the cavity β-CD, which contributed to the increase of entropy.
The influence of temperature on encapsulation of various guest mercaptans in β-cyclodextrin(β-CD) was investigated by the competitive UV-Vis spectrophotometric method. The results indicated that β-CD could include different mercaptans to form inclusion compounds at different temperatures. The inclusion stability constants of β-CD including 1-butanethiol at 25.0, 30.0, 35.0, 40.0 and 50.0℃, were 49.37, 66.39, 93.88, 124.5, and 197.61 L/mol, respectively, and those of β-CD wrapping 2-methyl-1-propanethiol were 326.0, 364.6, 415.3, 472.2, and 592.4 L/mol, respectively. The thermodynamic parameters ΔG, ΔH, and ΔS of the inclusion process were -9.661 kJ/mol, 35.85 kJ/mol, and 152.63 J/(mol·K) for 1-butanethiol, and -14.34 kJ/mol, 19.35 kJ/mol, and 112.98 J/(mol·K) for 2-methyl-1-propanethiol, respectively. It was found that the inclusion abilities of β-CD encapsulating various mercaptans were all enhanced with the increase of temperature; β-CD could spontaneously include various mercaptans in the temperature range studied, and the inclusion process was endothermic and controlled by entropy. The outer water shell of the hydrophobic alkyl of the mercaptan was destroged, causing the increase of the number of free molecules and the increase of the degree of freedom for the hydrophobic alkyl of the mercaptan inserted into the cavity β-CD, which contributed to the increase of entropy.
2007, 24(10): 1206-1210
Abstract:
Flavonoids were extracted from the buds of Sophora japonica L. by different methods, such as alkali dissolution of acid sedimentation, ethanol reflux, and ultrasonic-assisted methods. The extraction conditions, including the pH of the base and the kind of stabilizer were researched as well. Furthermore, with rutin as a control, thermal characteristics of flavonoids from the buds of Sophora japonica L. were determined Via the TG-DTG curves. The results showed that every sample had different mass loss, curve shape, and peak location related to different extraction technology. The TG-DTG characteristics of the products extracted by alkali dissolution of acid sedimentation with the extract adjusted to pH=9 and borax as the stabilizer were similar to that of standard rutin. Meanwhile, the yield and purity of the products extracted by the above optimum extraction technology were higher than others. Therefore, the thermal analysis fingerprint could serve as a tool for quality control of flavonoids from the buds of Sophora japonica L.
Flavonoids were extracted from the buds of Sophora japonica L. by different methods, such as alkali dissolution of acid sedimentation, ethanol reflux, and ultrasonic-assisted methods. The extraction conditions, including the pH of the base and the kind of stabilizer were researched as well. Furthermore, with rutin as a control, thermal characteristics of flavonoids from the buds of Sophora japonica L. were determined Via the TG-DTG curves. The results showed that every sample had different mass loss, curve shape, and peak location related to different extraction technology. The TG-DTG characteristics of the products extracted by alkali dissolution of acid sedimentation with the extract adjusted to pH=9 and borax as the stabilizer were similar to that of standard rutin. Meanwhile, the yield and purity of the products extracted by the above optimum extraction technology were higher than others. Therefore, the thermal analysis fingerprint could serve as a tool for quality control of flavonoids from the buds of Sophora japonica L.
2007, 24(10): 1211-1215
Abstract:
A trimericationic surfactant(Ⅲ-12-4) was prepared by ring-opening and quaternization reactions from epichlorohydrin, tertiary amine and glycerin with water as the solvent. The yield of Ⅲ-12-4 was 86.9%. The surfactant was characterized by MS and elemental analysis. The surface properties of Ⅲ-12-4 and sodium dodecyl sulphate(SDS) mixing systerm were determined by means of surface tension measurement using DSC apparatus. The development of micropolarity and the micelle aggregation number(Nm) of Ⅲ-12-4/SDS were assesed by steady fluorescence prob method. The results indicated that compared with monosurfactant system, the mixing systerm exhibited lower critical micelle concentration(cmc) and more effective surface tension reduction, showing synergistic effect. When n(Ⅲ-12-4):n(SDS)=3:7, the critical surface tension(γcmc) and critical micelle concentration(cmc) were 16.95 mN/m, 1.33×10-5 mol/L respectively, and the micelle aggregation number was 1/6 of that of SDS. The mixing micelle was more compact. Micropolarity was lower.
A trimericationic surfactant(Ⅲ-12-4) was prepared by ring-opening and quaternization reactions from epichlorohydrin, tertiary amine and glycerin with water as the solvent. The yield of Ⅲ-12-4 was 86.9%. The surfactant was characterized by MS and elemental analysis. The surface properties of Ⅲ-12-4 and sodium dodecyl sulphate(SDS) mixing systerm were determined by means of surface tension measurement using DSC apparatus. The development of micropolarity and the micelle aggregation number(Nm) of Ⅲ-12-4/SDS were assesed by steady fluorescence prob method. The results indicated that compared with monosurfactant system, the mixing systerm exhibited lower critical micelle concentration(cmc) and more effective surface tension reduction, showing synergistic effect. When n(Ⅲ-12-4):n(SDS)=3:7, the critical surface tension(γcmc) and critical micelle concentration(cmc) were 16.95 mN/m, 1.33×10-5 mol/L respectively, and the micelle aggregation number was 1/6 of that of SDS. The mixing micelle was more compact. Micropolarity was lower.
2007, 24(10): 1216-1218
Abstract:
2,6-Dimethylphenyl boronic acid was prepared from tributyl borate and Grignard reagent. An optimized process was obtained by investigating the influence of temperature, boronization reagent and reactant proportion on the yield. Grignard reagent was prepared from 2,6-dimethylphenyl bromide and 0.12 mol Mg at 43℃ in 1.5 h with a yield of 98.2%, then it reacted with 0.2 mol tributyl borate at -10℃, and the reaction mixture was hydrolyzed in an acid medium after the temperature was increased to 20℃ in 2 h. The total yield is 72.2%, which is much higher than that(51%) of using organic lithium and the experimental conditions are more moderate. The product was characterized by 1H NMR, mass spectrometry and IR.
2,6-Dimethylphenyl boronic acid was prepared from tributyl borate and Grignard reagent. An optimized process was obtained by investigating the influence of temperature, boronization reagent and reactant proportion on the yield. Grignard reagent was prepared from 2,6-dimethylphenyl bromide and 0.12 mol Mg at 43℃ in 1.5 h with a yield of 98.2%, then it reacted with 0.2 mol tributyl borate at -10℃, and the reaction mixture was hydrolyzed in an acid medium after the temperature was increased to 20℃ in 2 h. The total yield is 72.2%, which is much higher than that(51%) of using organic lithium and the experimental conditions are more moderate. The product was characterized by 1H NMR, mass spectrometry and IR.
2007, 24(10): 1219-1221
Abstract:
The samples for GFAAS analysis were pretreated by digesting with concentrated nitric acid and hydrogen peroxide. The best conditions were confirmed by the investigation of wavelength, spectral width, lamp-current, dry temperature, ashing temperature and atomization temperature, so the contents of Pb and Cd in Yin zhi huang injection and four medicinal materials were determined by GFAAS. 0.002% citric acid was used as matrix modifier to increase the ashing temperature, eliminate the background interference, improve the atomy absorption peak and enhance the sensitivity. The linear regression equation, the correlation coefficient and the detection limit are:APb=0.003 3C+0.040 72, rPb=0.999 1, 4×10-8 mg/L; ACb=0.088 9C+0.215 8, rCb=0.999 5, 2×10-9 mg/L, respectively. The recoveries of this method are in a range of 99.0%~110%, with a RSD' value of less than 2.5%. This method is proved to be simple, rapid and high accuracy with satisfactory results, and it can provide a simple and reliable method for the determination of trace elements in the Chinese traditional medicine.
The samples for GFAAS analysis were pretreated by digesting with concentrated nitric acid and hydrogen peroxide. The best conditions were confirmed by the investigation of wavelength, spectral width, lamp-current, dry temperature, ashing temperature and atomization temperature, so the contents of Pb and Cd in Yin zhi huang injection and four medicinal materials were determined by GFAAS. 0.002% citric acid was used as matrix modifier to increase the ashing temperature, eliminate the background interference, improve the atomy absorption peak and enhance the sensitivity. The linear regression equation, the correlation coefficient and the detection limit are:APb=0.003 3C+0.040 72, rPb=0.999 1, 4×10-8 mg/L; ACb=0.088 9C+0.215 8, rCb=0.999 5, 2×10-9 mg/L, respectively. The recoveries of this method are in a range of 99.0%~110%, with a RSD' value of less than 2.5%. This method is proved to be simple, rapid and high accuracy with satisfactory results, and it can provide a simple and reliable method for the determination of trace elements in the Chinese traditional medicine.
2007, 24(10): 1222-1224
Abstract:
Two novel DAR yellow couplers in which there is cyclic acylphenylhydrazine as the development accelerating group, and 6-aminobenzimidazole or phenylthioltriogenazole as the adsorption group were synthesized, and the yield was 60.8% and 48.2% respectively. The structures were confirmed by IR, 1H NMR, MS and elemental analysis. In practical application, the photosensitivity was increased but the fog was not increased.
Two novel DAR yellow couplers in which there is cyclic acylphenylhydrazine as the development accelerating group, and 6-aminobenzimidazole or phenylthioltriogenazole as the adsorption group were synthesized, and the yield was 60.8% and 48.2% respectively. The structures were confirmed by IR, 1H NMR, MS and elemental analysis. In practical application, the photosensitivity was increased but the fog was not increased.
