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2019 Volume 82 Issue 12
2019, 82(12): 1059-1066
Abstract:
The visual analysis based on surface plasmon resonance (SPR) of gold nanoparticles has been applied for the detection of numerous analytes owing to high sensitivity, good designability, and fast analytical process. Thus, the detection method has great application potential. In this paper, the research progress in visual analysis based on the SPR of gold nanoparticles is reviewed, and its development trend is prospected.
The visual analysis based on surface plasmon resonance (SPR) of gold nanoparticles has been applied for the detection of numerous analytes owing to high sensitivity, good designability, and fast analytical process. Thus, the detection method has great application potential. In this paper, the research progress in visual analysis based on the SPR of gold nanoparticles is reviewed, and its development trend is prospected.
2019, 82(12): 1067-1072
Abstract:
Foodborne pathogen contamination is one of the main factors causing food safety problems, and it poses a serious threat to human health. Vancomycin is a small molecule with specific recognition function of gram-positive bacteria, which can be modified on magnetic nanoparticles, to obtain the ability of capturing target bacteria. Combined with other detection methods, vancomycin can be used to achieve the purpose of capturing and detecting of gram-positive bacteria. In this paper, the research progress of vancomycin-functionalized magnetic beads in the isolation and detection of Gram-positive bacteria was reviewed. The effects of different modification ways and detection methods of vancomycin on the detection results were analyzed and compared. Finally, the problems of vancomycin in the detection of foodborne pathogenic bacteria were pointed out, and the future application of vancomycin was prospected.
Foodborne pathogen contamination is one of the main factors causing food safety problems, and it poses a serious threat to human health. Vancomycin is a small molecule with specific recognition function of gram-positive bacteria, which can be modified on magnetic nanoparticles, to obtain the ability of capturing target bacteria. Combined with other detection methods, vancomycin can be used to achieve the purpose of capturing and detecting of gram-positive bacteria. In this paper, the research progress of vancomycin-functionalized magnetic beads in the isolation and detection of Gram-positive bacteria was reviewed. The effects of different modification ways and detection methods of vancomycin on the detection results were analyzed and compared. Finally, the problems of vancomycin in the detection of foodborne pathogenic bacteria were pointed out, and the future application of vancomycin was prospected.
2019, 82(12): 1073-1078
Abstract:
High performance liquid chromatography (HPLC) is the most commonly used technique in separation and analysis at present. The classification and selection of columns are the important parts of analytical method development and validation. In this paper, the recent progresses in the application of mathematical models and statistical method in chromatographic development are reviewed. The improvement and application of HPLC column characterization databases and quantitative structure-retention relationship model are summarized. The progresses in computer technology used in HPLC development, the HPLC column classification system applied in column selection and ultrahigh pressure liquid chromatography column characterization model are also introduced. In addition, the future prospects for application of computer technology combined with molecular simulation and artificial neural network in HPLC development are expected.
High performance liquid chromatography (HPLC) is the most commonly used technique in separation and analysis at present. The classification and selection of columns are the important parts of analytical method development and validation. In this paper, the recent progresses in the application of mathematical models and statistical method in chromatographic development are reviewed. The improvement and application of HPLC column characterization databases and quantitative structure-retention relationship model are summarized. The progresses in computer technology used in HPLC development, the HPLC column classification system applied in column selection and ultrahigh pressure liquid chromatography column characterization model are also introduced. In addition, the future prospects for application of computer technology combined with molecular simulation and artificial neural network in HPLC development are expected.
2019, 82(12): 1079-1085
Abstract:
The non-noble metal complexes exhibit catalytic activity comparable to that of noble metal complexes in catalytic reactions, and have the advantages of low cost and non-toxicity, and thus have become a hot research topic in recent years. The research progress in the construction of C-C and C-N bonds catalyzed by iron, cobalt and manganese complexes are mainly introduced in this paper, in order to provide reference for the future application of low-cost metal complexes in the field of catalysis.
The non-noble metal complexes exhibit catalytic activity comparable to that of noble metal complexes in catalytic reactions, and have the advantages of low cost and non-toxicity, and thus have become a hot research topic in recent years. The research progress in the construction of C-C and C-N bonds catalyzed by iron, cobalt and manganese complexes are mainly introduced in this paper, in order to provide reference for the future application of low-cost metal complexes in the field of catalysis.
2019, 82(12): 1086-1092
Abstract:
There is an urgent need in the wastewater treatment to prepare adsorbent with multiple stimuli and self-healing properties. Herein, an injectable supramolecular hydrogel was formed by sodium alginate (ALG) and zinc ions (Zn2+), and the procedure was very simple (Zn2+ dropped directly into ALG) and fast (only 2 s). The as-prepared hydrogel showed multi-stimuli (pH, metal salts, etc.) responsiveness and self-healing properties, which are crucial for highly efficient organic pollution adsorption. Furthermore, the adsorption performance of the hydrogel was investigated with methylene blue (MB) as model dye. The maximum MB adsorption capacity of hydrogel is 5.3 mg/g, and it has good adsorption capacity for low concentration pollutants (removal rate exceeds 80%). The adsorption kinetics were in accordance with the pseudo-second-order kinetic equation, and the Freundlich model could well fit the isothermal adsorption process, indicating that the adsorption of MB by ALG-Zn hydrogel is dominated by multi-layer adsorption. The prepared ALG-Zn supramolecular hydrogel as a popular adsorbent could be applied in wastewater treatment.
There is an urgent need in the wastewater treatment to prepare adsorbent with multiple stimuli and self-healing properties. Herein, an injectable supramolecular hydrogel was formed by sodium alginate (ALG) and zinc ions (Zn2+), and the procedure was very simple (Zn2+ dropped directly into ALG) and fast (only 2 s). The as-prepared hydrogel showed multi-stimuli (pH, metal salts, etc.) responsiveness and self-healing properties, which are crucial for highly efficient organic pollution adsorption. Furthermore, the adsorption performance of the hydrogel was investigated with methylene blue (MB) as model dye. The maximum MB adsorption capacity of hydrogel is 5.3 mg/g, and it has good adsorption capacity for low concentration pollutants (removal rate exceeds 80%). The adsorption kinetics were in accordance with the pseudo-second-order kinetic equation, and the Freundlich model could well fit the isothermal adsorption process, indicating that the adsorption of MB by ALG-Zn hydrogel is dominated by multi-layer adsorption. The prepared ALG-Zn supramolecular hydrogel as a popular adsorbent could be applied in wastewater treatment.
2019, 82(12): 1093-1097
Abstract:
Uniform Cu nanoparticles were synthesized via complexation reaction and solvothermal reaction by using copper chloride as reaction precursor, glucose as reducing agent and alkylamine (mixture of hexadecylamine and octadecylamine) as complexing agents and surface capping agents. Subsequently, the Cu nanoparticles which were 100 nm in diameter spontaneously grew into Cu nanorods (including nanoparticles). The morphological characteristics of the reduction products after solvothermal reaction for 1h, 3h and 5h were characterized respectively. It is deduced that the reduced Cu atoms first nucleated uniformly to form primary Cu nanoparticles, and then grew into five-fold twin secondary Cu nanoparticles through Ostwald aging process. Eventually, due to the high growth activity of the twin structure, anisotropy Cu nanorods were simply prepared under the surface coating of alkylamine. This strategy could provide an effective method for preparing copper nanorods and reduce the cost of synthesis of one-dimensional Cu nanomaterials.
Uniform Cu nanoparticles were synthesized via complexation reaction and solvothermal reaction by using copper chloride as reaction precursor, glucose as reducing agent and alkylamine (mixture of hexadecylamine and octadecylamine) as complexing agents and surface capping agents. Subsequently, the Cu nanoparticles which were 100 nm in diameter spontaneously grew into Cu nanorods (including nanoparticles). The morphological characteristics of the reduction products after solvothermal reaction for 1h, 3h and 5h were characterized respectively. It is deduced that the reduced Cu atoms first nucleated uniformly to form primary Cu nanoparticles, and then grew into five-fold twin secondary Cu nanoparticles through Ostwald aging process. Eventually, due to the high growth activity of the twin structure, anisotropy Cu nanorods were simply prepared under the surface coating of alkylamine. This strategy could provide an effective method for preparing copper nanorods and reduce the cost of synthesis of one-dimensional Cu nanomaterials.
2019, 82(12): 1098-1103
Abstract:
In order to optimize the metallurgical grade alumina production process, the modified Bayer process is used to produce more profitable flake α-Al2O3. The flaky α-Al2O3 was prepared by degumming sodium aluminate solution, strengthening the carbon concentration of spherical seed crystals, deep dehydrogenation under hydrothermal conditions and calcination under AlF3 conditions. The composition, phase and morphology of the product were analyzed by XRF, XRD and SEM. The results showed that when the addition of industrial aluminum hydroxide, calcium oxide and sodium oxalate are 45 g/L, 10 g/L and 10 g/L respectively, impurity iron, silicon, magnesium, zinc and calcium are reduced to (1.5, 5.0, 1.8, 1.5, 5.2)×10-5, respectively. Adding a small amount of spherical seed crystals in the carbonization, the decomposition rate of the solution reaches 92% or more, and the product particle size is reduced and evenly distributed. Lowering the pH in dehydrogenation during hydrothermal deepening can promote the conversion of gibbsite to boehmite more thoroughly. When 2% AlF3 seed crystals were added, the washed hydrothermal product was calcined at 850℃ for 4 h, the ultrafine flaky α-Al2O3 with a purity of more than 99.96% and a regular morphology can be obtained.
In order to optimize the metallurgical grade alumina production process, the modified Bayer process is used to produce more profitable flake α-Al2O3. The flaky α-Al2O3 was prepared by degumming sodium aluminate solution, strengthening the carbon concentration of spherical seed crystals, deep dehydrogenation under hydrothermal conditions and calcination under AlF3 conditions. The composition, phase and morphology of the product were analyzed by XRF, XRD and SEM. The results showed that when the addition of industrial aluminum hydroxide, calcium oxide and sodium oxalate are 45 g/L, 10 g/L and 10 g/L respectively, impurity iron, silicon, magnesium, zinc and calcium are reduced to (1.5, 5.0, 1.8, 1.5, 5.2)×10-5, respectively. Adding a small amount of spherical seed crystals in the carbonization, the decomposition rate of the solution reaches 92% or more, and the product particle size is reduced and evenly distributed. Lowering the pH in dehydrogenation during hydrothermal deepening can promote the conversion of gibbsite to boehmite more thoroughly. When 2% AlF3 seed crystals were added, the washed hydrothermal product was calcined at 850℃ for 4 h, the ultrafine flaky α-Al2O3 with a purity of more than 99.96% and a regular morphology can be obtained.
2019, 82(12): 1104-1109
Abstract:
The influence of the different negative charges of κ-carrageenan and λ-carrageenan on the encapsulation properties of curcumin in BSA/carrageenan complexes was studied. BSA/carrageenan complexes with high stability were formed through the electrostatic attraction between BSA and carrageenan. Compared to pure BSA, BSA/carrageenan complexes could significantly increase the solubility and stability of curcumin. Absorption and fluorescence measurements indicated that curcumin is bound in the hydrophobic cavities of BSA through the hydrophobic force. The presence of carrageenan can stabilize the folded structure of BSA for providing curcumin with a more hydrophobic microenvironment. Compared to pure BSA and BSA/κ-carrageenan complexes, the values of binding constant and pKa1 are bigger for curcumin with BSA/λ-carrageenan complexes, where λ-carrageenan carries higher negative charge than κ-carrageenan.
The influence of the different negative charges of κ-carrageenan and λ-carrageenan on the encapsulation properties of curcumin in BSA/carrageenan complexes was studied. BSA/carrageenan complexes with high stability were formed through the electrostatic attraction between BSA and carrageenan. Compared to pure BSA, BSA/carrageenan complexes could significantly increase the solubility and stability of curcumin. Absorption and fluorescence measurements indicated that curcumin is bound in the hydrophobic cavities of BSA through the hydrophobic force. The presence of carrageenan can stabilize the folded structure of BSA for providing curcumin with a more hydrophobic microenvironment. Compared to pure BSA and BSA/κ-carrageenan complexes, the values of binding constant and pKa1 are bigger for curcumin with BSA/λ-carrageenan complexes, where λ-carrageenan carries higher negative charge than κ-carrageenan.
2019, 82(12): 1110-1114
Abstract:
INCB024360 is an indoleamine 2, 3-dioxygenase I inhibitor that has entered clinical trial, but the binding mechanism is still obscure. In this study, the binding pattern of IDO1and INCB024360 was investigated using molecular docking, molecular dynamics, binding free energy calculation methods and alanine scanning mutagenesis. The results showed that six hydrogen bonds are formed in the complex, the binding free energy is -70.82 kJ/mol, and the electrostatic force is the main driving forces, the polar solvation energy is the main resistance force. Moreover, the alanine scanning mutagenesis experiment revealed that Ser263 and Glu171 are the key amino acids for the combination, and the ΔΔGbind values are 15.35 kJ/mol and 54.39 kJ/mol, respectively. The results presented herein provide an important basis for elucidating the molecular mechanisms of binding between IDO1and INCB024360.
INCB024360 is an indoleamine 2, 3-dioxygenase I inhibitor that has entered clinical trial, but the binding mechanism is still obscure. In this study, the binding pattern of IDO1and INCB024360 was investigated using molecular docking, molecular dynamics, binding free energy calculation methods and alanine scanning mutagenesis. The results showed that six hydrogen bonds are formed in the complex, the binding free energy is -70.82 kJ/mol, and the electrostatic force is the main driving forces, the polar solvation energy is the main resistance force. Moreover, the alanine scanning mutagenesis experiment revealed that Ser263 and Glu171 are the key amino acids for the combination, and the ΔΔGbind values are 15.35 kJ/mol and 54.39 kJ/mol, respectively. The results presented herein provide an important basis for elucidating the molecular mechanisms of binding between IDO1and INCB024360.
2019, 82(12): 1115-1120
Abstract:
1, 2, 4-triazole thioether acetamide derivatives 6a~6m were synthesized from 3, 4, 5-trimethoxy-benzoic acid through esterification, hydrazinolysis, cyclization, etherification, hydrolysis and condensation, and their structures were confirmed by 1H NMR, 13C NMR, EMI-MS and elemental analysis. Preliminary bioactivity results indicated that compounds 6a~6m have a certain inhibitory on B. dothidea, Phomopsis sp. and B. cinerea in kiwi soft rot at the concentration of 50μg/mL. The Inhibition rate of compounds 6k and 6l against B. dothidea, Phomopsis sp. and B. cinerea were 83.4% to 91.3%. Meanwhile, the EC50 value of compound 6k against B. dothidea and Phomopsis sp. were 46.6 μg/mL and 30.8 μg/mL, respectively, which were superior to that of the commercial agent pyrimethanil (57.6 μg/mL and 32.1 μg/mL). These results indicated that 1, 2, 4-triazole thioether acetamides have good fungicidal activities, and the results herein can provide reference for further development of highly active compounds.
1, 2, 4-triazole thioether acetamide derivatives 6a~6m were synthesized from 3, 4, 5-trimethoxy-benzoic acid through esterification, hydrazinolysis, cyclization, etherification, hydrolysis and condensation, and their structures were confirmed by 1H NMR, 13C NMR, EMI-MS and elemental analysis. Preliminary bioactivity results indicated that compounds 6a~6m have a certain inhibitory on B. dothidea, Phomopsis sp. and B. cinerea in kiwi soft rot at the concentration of 50μg/mL. The Inhibition rate of compounds 6k and 6l against B. dothidea, Phomopsis sp. and B. cinerea were 83.4% to 91.3%. Meanwhile, the EC50 value of compound 6k against B. dothidea and Phomopsis sp. were 46.6 μg/mL and 30.8 μg/mL, respectively, which were superior to that of the commercial agent pyrimethanil (57.6 μg/mL and 32.1 μg/mL). These results indicated that 1, 2, 4-triazole thioether acetamides have good fungicidal activities, and the results herein can provide reference for further development of highly active compounds.
2019, 82(12): 1121-1125
Abstract:
Expanded graphite was prepared by microwave method with natural flake graphite as raw material, concentrated sulfuric acid and nitric acid as intercalating agent, potassium ferrite as oxidant. The structure was characterized by IR spectrum, XRD and SEM. The effects of the amount of mixed acid and oxidizing agent, the proportion of mixed acid, the intercalated reaction temperature, and the intercalated reaction time on the expanding volume of obtained expanded graphite were discussed. Experimental results showed that when natural flake graphite (g):potassium ferrite (g):mixed acid (mL) is 1:0.3:18, sulfuric acid:nitric acid is 2:1, intercalated reaction temperature is 35℃, reaction time is 60min, the expanding volume reached about 75 mL/g, which is about 87.5% higher than when the sulfuric acid was used as the intercalant.
Expanded graphite was prepared by microwave method with natural flake graphite as raw material, concentrated sulfuric acid and nitric acid as intercalating agent, potassium ferrite as oxidant. The structure was characterized by IR spectrum, XRD and SEM. The effects of the amount of mixed acid and oxidizing agent, the proportion of mixed acid, the intercalated reaction temperature, and the intercalated reaction time on the expanding volume of obtained expanded graphite were discussed. Experimental results showed that when natural flake graphite (g):potassium ferrite (g):mixed acid (mL) is 1:0.3:18, sulfuric acid:nitric acid is 2:1, intercalated reaction temperature is 35℃, reaction time is 60min, the expanding volume reached about 75 mL/g, which is about 87.5% higher than when the sulfuric acid was used as the intercalant.
2019, 82(12): 1126-1129
Abstract:
1α-hydroxydehydroepiandrosterone was prepared from androsta-1, 4-diene-3, 17-dione through six steps including bromination and elimination, protection of carbonyl group, oxidation, incomplete hydrogenation and deprotection, with an overall yield of 27.3%. The method is economical, technically feasible, and environment-friendly; it can provide reference for the scale production of 1α-hydroxydehydroepiandrosterone and research of vitamin D drugs.
1α-hydroxydehydroepiandrosterone was prepared from androsta-1, 4-diene-3, 17-dione through six steps including bromination and elimination, protection of carbonyl group, oxidation, incomplete hydrogenation and deprotection, with an overall yield of 27.3%. The method is economical, technically feasible, and environment-friendly; it can provide reference for the scale production of 1α-hydroxydehydroepiandrosterone and research of vitamin D drugs.
2019, 82(12): 1130-1133
Abstract:
1, 4-Disubstituted 1, 2, 3-triazoles were synthesized by a CuI catalyzed one-pot reaction using 1, 1-dibromoalkenes and aryl azides as raw materials under room temperature. The structures of target compounds were characterized by IR, MS, 1H NMR and 13C NMR spectroscopy. Effects of the amount of catalyst, solvent and the reaction temperature on the yields of product were studied, and the possible reaction mechanism was proposed. This method has the advantages of environment friendly, mild reaction conditions, simple one pot operation and high yield.
1, 4-Disubstituted 1, 2, 3-triazoles were synthesized by a CuI catalyzed one-pot reaction using 1, 1-dibromoalkenes and aryl azides as raw materials under room temperature. The structures of target compounds were characterized by IR, MS, 1H NMR and 13C NMR spectroscopy. Effects of the amount of catalyst, solvent and the reaction temperature on the yields of product were studied, and the possible reaction mechanism was proposed. This method has the advantages of environment friendly, mild reaction conditions, simple one pot operation and high yield.
2019, 82(12): 1134-1137
Abstract:
A catalytic kinetic fluorescence method was developed using Co(Ⅱ) as a catalyst to catalyze the oxidation of morin by hydrogen peroxide. In the buffer solution of Na2B4O7·10H2O-NaOH at pH 10.70, trace cobalt (Ⅱ) ion has obvious catalytic effect on the oxidation of 4.0×10-7mol/L morin solution with 0.24% H2O2 solution. At the maximum wavelength (λex/λem=416.5nm/556.4nm), the fluorescence intensity of the system is linearly correlated with the concentration of Co (Ⅱ) in a concentration range of 0.8~8.0 μg/L, and the detection limit is 0.14 μg/L. The optimal conditions of the system were optimized and the ion interference of the system was investigated. The sierozem and molecular sieves samples were analyzed, the recovery rate were 95.0%~110.0% and 98.9%~101.9%.
A catalytic kinetic fluorescence method was developed using Co(Ⅱ) as a catalyst to catalyze the oxidation of morin by hydrogen peroxide. In the buffer solution of Na2B4O7·10H2O-NaOH at pH 10.70, trace cobalt (Ⅱ) ion has obvious catalytic effect on the oxidation of 4.0×10-7mol/L morin solution with 0.24% H2O2 solution. At the maximum wavelength (λex/λem=416.5nm/556.4nm), the fluorescence intensity of the system is linearly correlated with the concentration of Co (Ⅱ) in a concentration range of 0.8~8.0 μg/L, and the detection limit is 0.14 μg/L. The optimal conditions of the system were optimized and the ion interference of the system was investigated. The sierozem and molecular sieves samples were analyzed, the recovery rate were 95.0%~110.0% and 98.9%~101.9%.
2019, 82(12): 1138-1140
Abstract:
In this article, we made a theoretical analysis and experimental study to the problems of preparing molybdic acid ammonium solution in inorganic chemistry teaching experiment. To solve these problems, we present a simple and feasible method for preparing molybdic acid ammonium solution. Ion identification experiment results showed that molybdic acid ammonium solution prepared by as-presented method was sensitive to phosphate ion. The whole process was specific to phosphate ion, and the satisfied experimental results in the teaching experiment were achieved. After storing the molybdic acid ammonium solution prepared by this method for 1 year, the ion identification experiment showed similar result for phosphate ion identification. It means that the short shelf-time problem of molybdic acid ammonium solution in the inorganic chemistry teaching experiment has be sloved saccelofully.
In this article, we made a theoretical analysis and experimental study to the problems of preparing molybdic acid ammonium solution in inorganic chemistry teaching experiment. To solve these problems, we present a simple and feasible method for preparing molybdic acid ammonium solution. Ion identification experiment results showed that molybdic acid ammonium solution prepared by as-presented method was sensitive to phosphate ion. The whole process was specific to phosphate ion, and the satisfied experimental results in the teaching experiment were achieved. After storing the molybdic acid ammonium solution prepared by this method for 1 year, the ion identification experiment showed similar result for phosphate ion identification. It means that the short shelf-time problem of molybdic acid ammonium solution in the inorganic chemistry teaching experiment has be sloved saccelofully.
2019, 82(12): 1141-1146
Abstract:
Since the composition of graphite and diamond was identified as carbon in the 18th century, the concept of carbon element was initially formed. At the end of the 20th century, the discovery of the fullerene family, including C60, broke through the understanding of carbon. Subsequently, the appearance of carbon nanotubes, graphene, graphdiyne and T-carbon reinterpreted the concept of carbon element. The discovery of several new carbon qualities establishes a carbon paradigm from zero dimension to three dimension, and opens a new chapter in the research and application of "carbon elements".
Since the composition of graphite and diamond was identified as carbon in the 18th century, the concept of carbon element was initially formed. At the end of the 20th century, the discovery of the fullerene family, including C60, broke through the understanding of carbon. Subsequently, the appearance of carbon nanotubes, graphene, graphdiyne and T-carbon reinterpreted the concept of carbon element. The discovery of several new carbon qualities establishes a carbon paradigm from zero dimension to three dimension, and opens a new chapter in the research and application of "carbon elements".
