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2018 Volume 35 Issue 6
2018, 35(6): 613-624
doi: 10.11944/j.issn.1000-0518.2018.06.170385
Abstract:
The development of renewable clean energy is of great importance for human sustainable development. Nanopores and nanochannels based electrokinetical energy conversion systems provide us new choices for future clean energy resource development. Because these systems can transfer fluidic mechanical energy to electrical energy, they could be applied in the fields such as marine energy, self-driving nano-machines and micro-electrical mechanical systems. The interplay between solid pores and liquid interface is crucial for the energy conversion process inside nanopores and nanochannels. Artificial design, chemical modification and optimization for the interfacial structure of the energy conversion systems are key factors to improve the energy conversion efficiency. With rapid development of nanotechnology and the further study of the physical chemistry of surfaces, we can effectively and precisely prepare nanofluid power generation systems. This review mainly introduced basic concepts and advance progress of nanopores and nanochannels based electrokinetical energy conversion systems. We hope this review will be inspiring for scientists in the area of developing and applying of electrokinetic energy conversion systems, nano-generators, self-actuated nano-machines and wearable devices, etc.
The development of renewable clean energy is of great importance for human sustainable development. Nanopores and nanochannels based electrokinetical energy conversion systems provide us new choices for future clean energy resource development. Because these systems can transfer fluidic mechanical energy to electrical energy, they could be applied in the fields such as marine energy, self-driving nano-machines and micro-electrical mechanical systems. The interplay between solid pores and liquid interface is crucial for the energy conversion process inside nanopores and nanochannels. Artificial design, chemical modification and optimization for the interfacial structure of the energy conversion systems are key factors to improve the energy conversion efficiency. With rapid development of nanotechnology and the further study of the physical chemistry of surfaces, we can effectively and precisely prepare nanofluid power generation systems. This review mainly introduced basic concepts and advance progress of nanopores and nanochannels based electrokinetical energy conversion systems. We hope this review will be inspiring for scientists in the area of developing and applying of electrokinetic energy conversion systems, nano-generators, self-actuated nano-machines and wearable devices, etc.
2018, 35(6): 625-644
doi: 10.11944/j.issn.1000-0518.2018.06.170292
Abstract:
Polyoxometalate(POM) is an anion cluster composed of transition metal and oxygen atoms. Due to its special molecular structure and excellent physical and chemical properties, POM has a wide range of applications in catalysis, surface and supramolecular chemistry, as well as biological, pharmaceutical, and material sciences. POM in dilute aqueous solution can occur self-aggregation, forming a "ordered aggregates structure" similar to the structure of amphiphilic molecule in solution, which gives new structure and property for the development of new nano-devices and in the field of catalysis, medicines and other applications. This review briefly introduced the structure, properties and applications of POM, and summarized the research status and new progress of self-aggregation of POM in solution.
Polyoxometalate(POM) is an anion cluster composed of transition metal and oxygen atoms. Due to its special molecular structure and excellent physical and chemical properties, POM has a wide range of applications in catalysis, surface and supramolecular chemistry, as well as biological, pharmaceutical, and material sciences. POM in dilute aqueous solution can occur self-aggregation, forming a "ordered aggregates structure" similar to the structure of amphiphilic molecule in solution, which gives new structure and property for the development of new nano-devices and in the field of catalysis, medicines and other applications. This review briefly introduced the structure, properties and applications of POM, and summarized the research status and new progress of self-aggregation of POM in solution.
2018, 35(6): 645-651
doi: 10.11944/j.issn.1000-0518.2018.06.170214
Abstract:
A novel methodology for the synthesis of 2-hydroxyisophthalates through cascade reactions of 1, 2-allenic ketones with ethyl acetonedicarboxylate using K2CO3 as the promoter under extremely mild conditions has been developed. Under optimal reaction conditions, a series of 2-hydroxyisophthalates derivatives were obtained with 73%~85% yield. The formation of the title compounds involves firstly a Michael addition of active methylene compounds and allenic ketone followed by its intramolecular condensation. Notable features of this protocol include simple starting materials, high yield, and easiness of handling.
A novel methodology for the synthesis of 2-hydroxyisophthalates through cascade reactions of 1, 2-allenic ketones with ethyl acetonedicarboxylate using K2CO3 as the promoter under extremely mild conditions has been developed. Under optimal reaction conditions, a series of 2-hydroxyisophthalates derivatives were obtained with 73%~85% yield. The formation of the title compounds involves firstly a Michael addition of active methylene compounds and allenic ketone followed by its intramolecular condensation. Notable features of this protocol include simple starting materials, high yield, and easiness of handling.
2018, 35(6): 652-658
doi: 10.11944/j.issn.1000-0518.2018.06.170228
Abstract:
The limit of small molecule photoinitiators to applications of food and medical materials due to the toxicity of its residual fragments can be solved by the macromolecular photoinitiators. In this paper, pentaerythritol tetrahydrobenzoylformate(PTF) was synthesized using benzoyl formic acid(BF) and pentaerythritol(PET) as raw materials by acid chloride method. The results of thermal analysis show that there is 15% mass loss at 225℃ for PTF and its thermal stability is better than that of 2-hydroxy-2-methyl-1-phenyl-1-propanone(1173 photoinitiator). The initial decomposition temperature and the temperature with the same mass loss for the photocurable coatings using PTF as the photoinitiator are 100℃ higher than those for coatings using 1173 photoinitiator. The results show that the maximum reaction rate is 0.037 s-1, the final double bond conversion is 39.5%, and PTF has higher photoinduced activity than 1173 in the trimethylolpropane triacrylate(TMPTA) polymerization by light-differential scanning calorimetry. The residue content of PTF is only 5% of that of 1173 photoinitiator under the same experimental conditions.
The limit of small molecule photoinitiators to applications of food and medical materials due to the toxicity of its residual fragments can be solved by the macromolecular photoinitiators. In this paper, pentaerythritol tetrahydrobenzoylformate(PTF) was synthesized using benzoyl formic acid(BF) and pentaerythritol(PET) as raw materials by acid chloride method. The results of thermal analysis show that there is 15% mass loss at 225℃ for PTF and its thermal stability is better than that of 2-hydroxy-2-methyl-1-phenyl-1-propanone(1173 photoinitiator). The initial decomposition temperature and the temperature with the same mass loss for the photocurable coatings using PTF as the photoinitiator are 100℃ higher than those for coatings using 1173 photoinitiator. The results show that the maximum reaction rate is 0.037 s-1, the final double bond conversion is 39.5%, and PTF has higher photoinduced activity than 1173 in the trimethylolpropane triacrylate(TMPTA) polymerization by light-differential scanning calorimetry. The residue content of PTF is only 5% of that of 1173 photoinitiator under the same experimental conditions.
2018, 35(6): 659-664
doi: 10.11944/j.issn.1000-0518.2018.06.170211
Abstract:
The addition of co-complexing agent is beneficial to improve the catalytic activity of the double metal cyanide(DMC) catalyst. In this paper poly(propylene carbonate tetrachlorophthalic phthalate)(PPCPA) terpolymers were successfully synthesized from carbon dioxide, propylene oxide and tetrachlorophthalic anhydride catalyzed by ball milling synthesized Zn-Co DMC catalysts. The properties and structures of Zn-Co DMC catalysts and the resulting terpolymers were characterized by Fourier transform infrared spectroscopy(FTIR), scanning electron microscope(SEM), X-ray diffraction(XRD), gel permeation chromatography(GPC) and thermogravimetric analysis(TG). The results show that the turnover number of Zn-Co DMC catalysts is up to 25.67~141.80, and the number-average relative molecular mass of PPCPA is up to 2.21×103~3.15×103 with a narrow polydispersity index of 1.04~1.24. Compared with polypropylene carbonate(PPC), PPCPA shows a higher thermal stability, and the thermal decomposition temperature of PPCPA is increased by 129.8℃.
The addition of co-complexing agent is beneficial to improve the catalytic activity of the double metal cyanide(DMC) catalyst. In this paper poly(propylene carbonate tetrachlorophthalic phthalate)(PPCPA) terpolymers were successfully synthesized from carbon dioxide, propylene oxide and tetrachlorophthalic anhydride catalyzed by ball milling synthesized Zn-Co DMC catalysts. The properties and structures of Zn-Co DMC catalysts and the resulting terpolymers were characterized by Fourier transform infrared spectroscopy(FTIR), scanning electron microscope(SEM), X-ray diffraction(XRD), gel permeation chromatography(GPC) and thermogravimetric analysis(TG). The results show that the turnover number of Zn-Co DMC catalysts is up to 25.67~141.80, and the number-average relative molecular mass of PPCPA is up to 2.21×103~3.15×103 with a narrow polydispersity index of 1.04~1.24. Compared with polypropylene carbonate(PPC), PPCPA shows a higher thermal stability, and the thermal decomposition temperature of PPCPA is increased by 129.8℃.
2018, 35(6): 665-673
doi: 10.11944/j.issn.1000-0518.2018.06.170173
Abstract:
Alginate(Alg) is widely used in the field of tissue engineering because of its safe, non-toxic and biodegradable properties. Inspired by mussel adhesive protein, dopamine(DA) has excellent adhesion property and can self-oxidize to polydopamine(PDA) in weak basic buffer solution. Alg/PDA porous scaffolds were prepared by freeze-dry of Alg and PDA mixture. The results show that Alg/PDA porous scaffolds have relatively homogeneous internal structure. By changing the mass concentration of Alg, the pore size of the Alg/PDA complex scaffolds can be limited to 60~120 μm, and the porosity of the scaffolds can be controlled in the range of 80%~88% which is appropriate for the growth of bond cells. The biocompatibility results indicate that the scaffolds show low cytotoxicity.
Alginate(Alg) is widely used in the field of tissue engineering because of its safe, non-toxic and biodegradable properties. Inspired by mussel adhesive protein, dopamine(DA) has excellent adhesion property and can self-oxidize to polydopamine(PDA) in weak basic buffer solution. Alg/PDA porous scaffolds were prepared by freeze-dry of Alg and PDA mixture. The results show that Alg/PDA porous scaffolds have relatively homogeneous internal structure. By changing the mass concentration of Alg, the pore size of the Alg/PDA complex scaffolds can be limited to 60~120 μm, and the porosity of the scaffolds can be controlled in the range of 80%~88% which is appropriate for the growth of bond cells. The biocompatibility results indicate that the scaffolds show low cytotoxicity.
2018, 35(6): 674-678
doi: 10.11944/j.issn.1000-0518.2018.06.170241
Abstract:
A fluorescent material with high quantum yield(78%) was prepared using citric acid and triethylenetetramine as initial reagents in a facile way. The as-prepared system was characterized by ultraviolet(UV) absorption, fluorescence, Fourier transform infrared spectrometer(FTIR), nuclear magnetic resonance spectroscopy(NMR). The results show that the product belongs to a typical fluorescent material and the aggregation of a large number of carbonyl groups in the system may cause its intense fluorescence. It is confirmed that the material with high quantum yield can be an excellent fluorescent ink. This material has wide potential applications in the fields of patterning, anti-counterfeiting and optoelectronic devices.
A fluorescent material with high quantum yield(78%) was prepared using citric acid and triethylenetetramine as initial reagents in a facile way. The as-prepared system was characterized by ultraviolet(UV) absorption, fluorescence, Fourier transform infrared spectrometer(FTIR), nuclear magnetic resonance spectroscopy(NMR). The results show that the product belongs to a typical fluorescent material and the aggregation of a large number of carbonyl groups in the system may cause its intense fluorescence. It is confirmed that the material with high quantum yield can be an excellent fluorescent ink. This material has wide potential applications in the fields of patterning, anti-counterfeiting and optoelectronic devices.
2018, 35(6): 679-686
doi: 10.11944/j.issn.1000-0518.2018.06.170142
Abstract:
Water-jet printing has attracted wide attention owing to its green process and environmental friendliness. Therefore, it is significant for industrial preparation of water-jet rewritable paper. In this work, taking a hydrochromic dye indole[2, 1-b] oxazolidine(TM) for example, the industrial preparation process of water-jet rewritable paper based on polyethylene terephthalate(PET) instead of filter paper was explored in detail and successfully obtained via screening of surfactant, adjusting the amount of dye, and modulating coating thickness. The paper prepared via the optimized process exhibits great rewritable performance. Furthermore, successful small-scale production of this paper indicates that the optimized process can be widely applied in industrial production.
Water-jet printing has attracted wide attention owing to its green process and environmental friendliness. Therefore, it is significant for industrial preparation of water-jet rewritable paper. In this work, taking a hydrochromic dye indole[2, 1-b] oxazolidine(TM) for example, the industrial preparation process of water-jet rewritable paper based on polyethylene terephthalate(PET) instead of filter paper was explored in detail and successfully obtained via screening of surfactant, adjusting the amount of dye, and modulating coating thickness. The paper prepared via the optimized process exhibits great rewritable performance. Furthermore, successful small-scale production of this paper indicates that the optimized process can be widely applied in industrial production.
2018, 35(6): 687-691
doi: 10.11944/j.issn.1000-0518.2018.06.170288
Abstract:
A new type of hollow tubular superstructure composed of CuO nanosheets was fabricated from Cu2O@HKUST-1(HKUST-1=Cu3(BTC)2, BTC3-=benzene-1, 3, 5-tricarboxylate) nanowire through the hydrolysis of HKUST-1 shell and oxidation etching of Cu2O core. The as-obtained tubular CuO superstructures possess a large Brunauer-Emmett-Teller(BET) surface area(56.3 m2/g) and exhibit high catalytic performance in CO oxidation. The complete CO conversion temperature is 200℃. At 190℃, the value of CO conversion efficiency is 17.3 mmolCO/(gCuO·h).
A new type of hollow tubular superstructure composed of CuO nanosheets was fabricated from Cu2O@HKUST-1(HKUST-1=Cu3(BTC)2, BTC3-=benzene-1, 3, 5-tricarboxylate) nanowire through the hydrolysis of HKUST-1 shell and oxidation etching of Cu2O core. The as-obtained tubular CuO superstructures possess a large Brunauer-Emmett-Teller(BET) surface area(56.3 m2/g) and exhibit high catalytic performance in CO oxidation. The complete CO conversion temperature is 200℃. At 190℃, the value of CO conversion efficiency is 17.3 mmolCO/(gCuO·h).
2018, 35(6): 692-699
doi: 10.11944/j.issn.1000-0518.2018.06.170235
Abstract:
Bi2O2CO3 was synthesized by surfactant-assisted hydrothermal method. The dosage of cationic surfactant cetyltrimethylammonium bromide(CTAB), nonionic surfactant polyethylene glycol 8000(PEG8000), anionic surfactant sodium dodecyl sulfate(SDS), and coupling of SDS with CTAB as well as their influences on crystal plane, morphology, photoabsorption ability and photocatalytic activity of Bi2O2CO3 photocatalyst were investigated. The photocatalytic activity was evaluated by the degradation of rhodamine B solution(10 mg/L) under ultraviolet light irradiation. The results show that when the addition of Bi2O2CO3 is 6 mmol(2.9106 g), modified Bi2O2CO3 with SDS will inhibits the photocatalytic activity. The photocatalytic activity of Bi2O2CO3 is effectively improved by addition of 0.6 g CTAB in the hydrothermal process. A totally 0.3 g of SDS and CTAB can improve the photocatalytic activity of Bi2O2CO3. Addition of 0.3 g PEG8000 also promotes the photocatalytic activity of Bi2O2CO3.
Bi2O2CO3 was synthesized by surfactant-assisted hydrothermal method. The dosage of cationic surfactant cetyltrimethylammonium bromide(CTAB), nonionic surfactant polyethylene glycol 8000(PEG8000), anionic surfactant sodium dodecyl sulfate(SDS), and coupling of SDS with CTAB as well as their influences on crystal plane, morphology, photoabsorption ability and photocatalytic activity of Bi2O2CO3 photocatalyst were investigated. The photocatalytic activity was evaluated by the degradation of rhodamine B solution(10 mg/L) under ultraviolet light irradiation. The results show that when the addition of Bi2O2CO3 is 6 mmol(2.9106 g), modified Bi2O2CO3 with SDS will inhibits the photocatalytic activity. The photocatalytic activity of Bi2O2CO3 is effectively improved by addition of 0.6 g CTAB in the hydrothermal process. A totally 0.3 g of SDS and CTAB can improve the photocatalytic activity of Bi2O2CO3. Addition of 0.3 g PEG8000 also promotes the photocatalytic activity of Bi2O2CO3.
2018, 35(6): 700-707
doi: 10.11944/j.issn.1000-0518.2018.06.170234
Abstract:
The chalcogenidostannate compound Cs8Mn4Sn4Se16(1) and[Ni(1, 2-dap)3]2Cd2Sn2S8(2) were solvothermally synthesized by using the alkali metal in 1, 4-butanediamine, and 1, 2-propanediamine(1, 2-dap) coordinated transition metal as guest cations, respectively. Single-crystal X-ray, ultraviolet-visible(UV-Vis) diffuse reflectance spectroscopy and thermogravimetric analysis and differential scanning calorimetry(TG-DSC) indicate that the compounds 1 and 2 belong to orthorhombic system Fddd group and Cmcm group. Both 1 and 2 consist of one-dimensional straight anionic chains composed of edge sharing tetrahedron SnQ4(Q=S, Se) or TMQ4(TM=Mn, Cd). The UV-visble diffuse reflectance data show that the band gaps of compounds 1 and 2 are 1.70 eV and 2.21 eV, respectively, which implies that compounds 1 and 2 have semiconductor properties. The TG-DSC results indicate good thermal stability of compunds 1 and 2 in some temperature condition.
The chalcogenidostannate compound Cs8Mn4Sn4Se16(1) and[Ni(1, 2-dap)3]2Cd2Sn2S8(2) were solvothermally synthesized by using the alkali metal in 1, 4-butanediamine, and 1, 2-propanediamine(1, 2-dap) coordinated transition metal as guest cations, respectively. Single-crystal X-ray, ultraviolet-visible(UV-Vis) diffuse reflectance spectroscopy and thermogravimetric analysis and differential scanning calorimetry(TG-DSC) indicate that the compounds 1 and 2 belong to orthorhombic system Fddd group and Cmcm group. Both 1 and 2 consist of one-dimensional straight anionic chains composed of edge sharing tetrahedron SnQ4(Q=S, Se) or TMQ4(TM=Mn, Cd). The UV-visble diffuse reflectance data show that the band gaps of compounds 1 and 2 are 1.70 eV and 2.21 eV, respectively, which implies that compounds 1 and 2 have semiconductor properties. The TG-DSC results indicate good thermal stability of compunds 1 and 2 in some temperature condition.
2018, 35(6): 708-713
doi: 10.11944/j.issn.1000-0518.2018.06.170281
Abstract:
In order to study the secondary metabolites of dihydroisocoumarin compounds from mangrove endophytic fungi Fusarium sp. F67 and B42, the metabolites of strains F67 and B42 were isolated and purified by chromatographic techniques, and their structures were determined as follows:3, 6, 8-trihydroxy-3, 4, 5, 7-tetramethyl-3, 4-dihydroisocoumarin(sclerotinin A)(1), dihydrocitrinone(2), 5-methylmellein(3), 5-carboxymellein(4), 4-hydroxymellein(5) and mellein(6). Antibacterial activities of compounds 1~4 in 1.0 g/L show that the inhibitory zone against the tested strains ranges from 5.1 to 11.0 mm. Among them, compound 4 has the strongest antibacterial activities and the broadest bacteriostatic spectra. These results provide supplement to the research and development of new antibacterial drug.
In order to study the secondary metabolites of dihydroisocoumarin compounds from mangrove endophytic fungi Fusarium sp. F67 and B42, the metabolites of strains F67 and B42 were isolated and purified by chromatographic techniques, and their structures were determined as follows:3, 6, 8-trihydroxy-3, 4, 5, 7-tetramethyl-3, 4-dihydroisocoumarin(sclerotinin A)(1), dihydrocitrinone(2), 5-methylmellein(3), 5-carboxymellein(4), 4-hydroxymellein(5) and mellein(6). Antibacterial activities of compounds 1~4 in 1.0 g/L show that the inhibitory zone against the tested strains ranges from 5.1 to 11.0 mm. Among them, compound 4 has the strongest antibacterial activities and the broadest bacteriostatic spectra. These results provide supplement to the research and development of new antibacterial drug.
2018, 35(6): 714-721
doi: 10.11944/j.issn.1000-0518.2018.06.170169
Abstract:
In order to avoid the aromatics waste and environmental pollution caused by ethylene bottom oil as a crude fuel for combustion, Fushun ethylene bottom oil was subjected to atmospheric distillation to obtain a fraction below 280℃. To achieve separation of ethylene bottom oil, the fraction below 280℃ was cut into 12 fractions(40~150℃, 150~170℃, 170~180℃, 180~190℃. 190~200℃, 200~210℃. 210~220℃, 220~230℃, 230~240℃, 240~250℃, 250~260℃. 260~280℃) by atmospheric distillation unit equipped with packed columns. The obtained 12 fractions were analyzed qualitatively and quantitatively by gas chromatography/mass spectrometry with an HP-5MS capillary column as the stationary phase. We hope it could provide valuable analytical data for the extraction of aromatic hydrocarbons, and the deep processing and utilization of ethylene bottom oil. The results indicate that the distillate below 280℃account for 52.2% of the total amount of ethylene bottom oil in Fushun, and mainly contained aromatic hydrocarbons with 1 to 4 rings. The mass fraction of monocyclic, tricyclic and tetracyclic aromatic hydrocarbons is small. The monocyclic aromatic hydrocarbons are mainly derivatives of benzene and indene that account for 5.8% and 6.172% of ethylene bottom oil in Fushun, respectively. The tricyclic and tetracyclic aromatic hydrocarbons account for 2.998% and mainly are acenaphthene, fluorene, anthracene, phenanthrene, pyrene and so on. The most abundant bicyclic aromatic hydrocarbons in Fushun ethylene bottom oil are naphthalene, followed by β-methylnaphthalene, α-methylnaphthalene and 1, 4-dihydronaphthalene with mass fraction of 41.152%, 16.729%, 12.089% and 9.046%, respectively. This research shows that ethylene bottom oil in Fushun can be used as good feedstock for extracting high value-added aromatic fine chemicals.
In order to avoid the aromatics waste and environmental pollution caused by ethylene bottom oil as a crude fuel for combustion, Fushun ethylene bottom oil was subjected to atmospheric distillation to obtain a fraction below 280℃. To achieve separation of ethylene bottom oil, the fraction below 280℃ was cut into 12 fractions(40~150℃, 150~170℃, 170~180℃, 180~190℃. 190~200℃, 200~210℃. 210~220℃, 220~230℃, 230~240℃, 240~250℃, 250~260℃. 260~280℃) by atmospheric distillation unit equipped with packed columns. The obtained 12 fractions were analyzed qualitatively and quantitatively by gas chromatography/mass spectrometry with an HP-5MS capillary column as the stationary phase. We hope it could provide valuable analytical data for the extraction of aromatic hydrocarbons, and the deep processing and utilization of ethylene bottom oil. The results indicate that the distillate below 280℃account for 52.2% of the total amount of ethylene bottom oil in Fushun, and mainly contained aromatic hydrocarbons with 1 to 4 rings. The mass fraction of monocyclic, tricyclic and tetracyclic aromatic hydrocarbons is small. The monocyclic aromatic hydrocarbons are mainly derivatives of benzene and indene that account for 5.8% and 6.172% of ethylene bottom oil in Fushun, respectively. The tricyclic and tetracyclic aromatic hydrocarbons account for 2.998% and mainly are acenaphthene, fluorene, anthracene, phenanthrene, pyrene and so on. The most abundant bicyclic aromatic hydrocarbons in Fushun ethylene bottom oil are naphthalene, followed by β-methylnaphthalene, α-methylnaphthalene and 1, 4-dihydronaphthalene with mass fraction of 41.152%, 16.729%, 12.089% and 9.046%, respectively. This research shows that ethylene bottom oil in Fushun can be used as good feedstock for extracting high value-added aromatic fine chemicals.
2018, 35(6): 722-728
doi: 10.11944/j.issn.1000-0518.2018.06.170245
Abstract:
A rapid and simple method based on ultrasound-assisted extraction, solid-phase extraction followed by high performance liquid chromatography(UAE-SPE-HPLC) was proposed for the determination of cephalosporin C(CPC) in soil. The optimum pre-treatment parameters for the soil samples contaminated with CPC are as follow:ultra-pure water as extraction solvent for CPC, SPE as solid phase extraction cartridge, 5.0 mL 10% methanol as rinse solvent, 2.0 mL 5% formic acid/methanol solution(volume ratio 50:50) as eluent. The results show that when 0.1% formic acid and methanol(95:5), 30℃ column temperature, and 254 nm detection wavelength were applied during the isocratic elution process, HPLC assay offeres a good potential for the sensitive and selective determination of CPC. The recovery rates for seven different treatments are 77.9%~98.8%, and the precision is 5.0%~6.3%(n=5). The limit of determination(LOD) and the limit of quantification(LOQ) in soil are 340.4 μg/kg and 1126.8 μg/kg, respectively. At the same time, this method was used to detect the positive soil near the pharmaceutical factory in Xinjiang. The experimental results of different batches show detected(below LOQ), 1532.1 μg/kg and detected(below LOQ), respectively. In conclusion, UAE-SPE-HPLC is simple and rapid. Its accuracy and precision are in line with the quality control requirements. It is suitable for the detection of trace CPC in soil.
A rapid and simple method based on ultrasound-assisted extraction, solid-phase extraction followed by high performance liquid chromatography(UAE-SPE-HPLC) was proposed for the determination of cephalosporin C(CPC) in soil. The optimum pre-treatment parameters for the soil samples contaminated with CPC are as follow:ultra-pure water as extraction solvent for CPC, SPE as solid phase extraction cartridge, 5.0 mL 10% methanol as rinse solvent, 2.0 mL 5% formic acid/methanol solution(volume ratio 50:50) as eluent. The results show that when 0.1% formic acid and methanol(95:5), 30℃ column temperature, and 254 nm detection wavelength were applied during the isocratic elution process, HPLC assay offeres a good potential for the sensitive and selective determination of CPC. The recovery rates for seven different treatments are 77.9%~98.8%, and the precision is 5.0%~6.3%(n=5). The limit of determination(LOD) and the limit of quantification(LOQ) in soil are 340.4 μg/kg and 1126.8 μg/kg, respectively. At the same time, this method was used to detect the positive soil near the pharmaceutical factory in Xinjiang. The experimental results of different batches show detected(below LOQ), 1532.1 μg/kg and detected(below LOQ), respectively. In conclusion, UAE-SPE-HPLC is simple and rapid. Its accuracy and precision are in line with the quality control requirements. It is suitable for the detection of trace CPC in soil.
2018, 35(6): 729-734
doi: 10.11944/j.issn.1000-0518.2018.06.170368
Abstract:
A new method for determination of total fluoride in chemical milling etching solution for titanium alloys based on in-situ hydrolysis of fluoride-titanium complex and on potentiometric titration with La(NO3)3 was developed. In hexamethylenetetramine(HMTA) buffer solution, the fluoride-titanium complex was hydrolyzed to release free fluoride ions. A fluoride ion-selective electrode(F-ISE) was used as the indicator electrode. Various parameters affecting the test(i.e., pH values of the solution, the dosage of HMTA solution and the concentration of titanium ion) were tested and optimized. It is shown that the test results are not interfered by the concentration of Ti(Ⅳ) in the range of 0~20 g/L, the relative standard deviation(RSDs, n=6) of the method ranges from 0.27% to 0.62% and the recovery by standard addition method is in the range of 99.5%~101.1%. The mechanism of hydrolysis of fluoride-titanium complex was discussed. The main form of fluoride presented in etching solution is TiF62-. Appropriate acidity is essential to the hydrolysis reaction. HMTA as a pH buffer provides a constant pH circumstance, while La(NO3)3 as the fluoride scavenger reduces the concentration of free fluoride and promotes the hydrolysis reaction dramatically. Accompanied by the titration reaction, the fluoride-titanium complex is hydrolyzed completely.
A new method for determination of total fluoride in chemical milling etching solution for titanium alloys based on in-situ hydrolysis of fluoride-titanium complex and on potentiometric titration with La(NO3)3 was developed. In hexamethylenetetramine(HMTA) buffer solution, the fluoride-titanium complex was hydrolyzed to release free fluoride ions. A fluoride ion-selective electrode(F-ISE) was used as the indicator electrode. Various parameters affecting the test(i.e., pH values of the solution, the dosage of HMTA solution and the concentration of titanium ion) were tested and optimized. It is shown that the test results are not interfered by the concentration of Ti(Ⅳ) in the range of 0~20 g/L, the relative standard deviation(RSDs, n=6) of the method ranges from 0.27% to 0.62% and the recovery by standard addition method is in the range of 99.5%~101.1%. The mechanism of hydrolysis of fluoride-titanium complex was discussed. The main form of fluoride presented in etching solution is TiF62-. Appropriate acidity is essential to the hydrolysis reaction. HMTA as a pH buffer provides a constant pH circumstance, while La(NO3)3 as the fluoride scavenger reduces the concentration of free fluoride and promotes the hydrolysis reaction dramatically. Accompanied by the titration reaction, the fluoride-titanium complex is hydrolyzed completely.
