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2017 Volume 80 Issue 1
2017, 80(1): 3-9
Abstract:
Metal-organic frameworks (MOFs), with well-defined porosity, rich structural diversity and tailable functionality, have drawn a great deal of attention from across the scientific community due to their potential applications in the fields of gas storage, separation, catalysis and chemical sensing, etc. However, MOF crystals are often fragile, insoluble and poor in processability. Commonly processing method is to fabricate MOFs into pellet. Yet the obtained samples can easily break down into tiny particles or fine powders, which might hamper their industrial applications. Herein, we developed four methods (in-situ interweaving, photo-induced postsynthetic polymerization, hot-pressing and electrospinning) to process MOFs into membranes, films and fibers. We further set out to explore their applications in the areas of electrochemistry, separation, detection, safety protection and even the possibility in industrial production.
Metal-organic frameworks (MOFs), with well-defined porosity, rich structural diversity and tailable functionality, have drawn a great deal of attention from across the scientific community due to their potential applications in the fields of gas storage, separation, catalysis and chemical sensing, etc. However, MOF crystals are often fragile, insoluble and poor in processability. Commonly processing method is to fabricate MOFs into pellet. Yet the obtained samples can easily break down into tiny particles or fine powders, which might hamper their industrial applications. Herein, we developed four methods (in-situ interweaving, photo-induced postsynthetic polymerization, hot-pressing and electrospinning) to process MOFs into membranes, films and fibers. We further set out to explore their applications in the areas of electrochemistry, separation, detection, safety protection and even the possibility in industrial production.
2017, 80(1): 10-33, 76
Abstract:
Supercapacitor (SC), also called electrochemical capacitor, which has higher power density and longer cycling life than lithium ion battery as well as higher energy density than dielectric capacitor, is a kind of promising energy storage device. The different kinds of flexible and wearable electronic devices are emerging with consumers' increasing requirements for electronic devices. Flexible SC, which is a kind of portable energy storage device, has attracted much attention. The two-dimensional planar-structure and one-dimensional fiber-shaped SCs have been developed rapidly with the flexible electronic devices advancing. In this review, the energy storage mechanism of SCs, the diverse performance metrics and evaluation for SCs as a foundation are first introduced to understand different research approaches. Then, the current state-of-the-art progress in devices' structure design and electrode materials fabrication of the flexible two-dimensional planar-structure and one-dimensional fiber-shaped SCs are summarized. Last, perspectives on the future development of flexible SCs and highlighted key technical challenges with hope of stimulating further research progress are presented.
Supercapacitor (SC), also called electrochemical capacitor, which has higher power density and longer cycling life than lithium ion battery as well as higher energy density than dielectric capacitor, is a kind of promising energy storage device. The different kinds of flexible and wearable electronic devices are emerging with consumers' increasing requirements for electronic devices. Flexible SC, which is a kind of portable energy storage device, has attracted much attention. The two-dimensional planar-structure and one-dimensional fiber-shaped SCs have been developed rapidly with the flexible electronic devices advancing. In this review, the energy storage mechanism of SCs, the diverse performance metrics and evaluation for SCs as a foundation are first introduced to understand different research approaches. Then, the current state-of-the-art progress in devices' structure design and electrode materials fabrication of the flexible two-dimensional planar-structure and one-dimensional fiber-shaped SCs are summarized. Last, perspectives on the future development of flexible SCs and highlighted key technical challenges with hope of stimulating further research progress are presented.
2017, 80(1): 34-40
Abstract:
With the rapid development of electric vehicles, smart grid and large-scale energy storage areas, the higher requirements for energy and power density of the lithium ion battery have been put forward. Therefore, developing a new type of cathode material which has good stability and high specific capacity is the key to further improve the energy density for lithium ion battery. Among different kinds of cathode materials, lithium rich ternary cathode material xLi2MnO3·(1-x) LiMn1/3Ni1/3Co1/3O2(0.1≤x≤0.5) is considered to be the most promising one due to its high specific capacity, high voltage and friendly to environment. In this paper, the research progress in lithium rich ternary cathode material and its crystal structure and electrochemical characteristics as well as the existing problems were introduced. The future development trends of xLi2MnO3·(1-x) LiMn1/3Ni1/3Co1/3O2(0.1≤x≤0.5) was also expected.
With the rapid development of electric vehicles, smart grid and large-scale energy storage areas, the higher requirements for energy and power density of the lithium ion battery have been put forward. Therefore, developing a new type of cathode material which has good stability and high specific capacity is the key to further improve the energy density for lithium ion battery. Among different kinds of cathode materials, lithium rich ternary cathode material xLi2MnO3·(1-x) LiMn1/3Ni1/3Co1/3O2(0.1≤x≤0.5) is considered to be the most promising one due to its high specific capacity, high voltage and friendly to environment. In this paper, the research progress in lithium rich ternary cathode material and its crystal structure and electrochemical characteristics as well as the existing problems were introduced. The future development trends of xLi2MnO3·(1-x) LiMn1/3Ni1/3Co1/3O2(0.1≤x≤0.5) was also expected.
2017, 80(1): 41-46
Abstract:
The immobilized enzyme has been widely applied to the food and medicine industrial production, and micro biochemical detection field for its advantages of high efficiency catalysis, recyclability and easy separation. The performance of immobilized enzyme is closely related to the carrier materials. As a new type of nano materials, graphene has excellent physical and chemical properties, which is an ideal carrier for the immobilization of enzyme. This article focused on the technology of immobilized enzyme using graphene as carrier for the past few years. The immobilization methods including physical adsorption, chemical bonding and encapsulation were particularly discussed. The recent applications of immobilized enzyme in the field of enzyme micro-reaction and biosensor were reviewed. The prospects of its future development were also outlined.
The immobilized enzyme has been widely applied to the food and medicine industrial production, and micro biochemical detection field for its advantages of high efficiency catalysis, recyclability and easy separation. The performance of immobilized enzyme is closely related to the carrier materials. As a new type of nano materials, graphene has excellent physical and chemical properties, which is an ideal carrier for the immobilization of enzyme. This article focused on the technology of immobilized enzyme using graphene as carrier for the past few years. The immobilization methods including physical adsorption, chemical bonding and encapsulation were particularly discussed. The recent applications of immobilized enzyme in the field of enzyme micro-reaction and biosensor were reviewed. The prospects of its future development were also outlined.
2017, 80(1): 47-52
Abstract:
In this work, a colorimetric biosensing platform for H2O2 and dopamine (DA) was constructed based on the catalytic activity of one type of Cu-MOF[Cu3(BTC)2(H2O)3, HKUST-1]. The color of o-phenylenediamine (OPD) can be changed significantly because of the oxidation of H2O2 catalyzed by HKUST-1. As a result, H2O2 and DA were detected rapidly and sensitively by our system. Under the optimum conditions, two linear relationships between the intensity of absorption peak at 415nm and the concentration of H2O2 (from 10 to 50 mmol/L and from 50 to 100 mmol/L, R=0.9947 and 0.9995) were obtained with the detection limit of 1.29 mmol/L. Besides, DA can resist the oxidation of OPD from H2O2, this platform was further used for rapid detection of DA with two linear ranges (from 0.25 to 5μmol/L and from 2.5 to 25μmol/L, R=0.9783 and 0.9705), and the detection limit was 0.262 μmol/L. Therefore, this work may broaden the applications of Cu-MOFs in biological molecular catalysis and biosensing fields.
In this work, a colorimetric biosensing platform for H2O2 and dopamine (DA) was constructed based on the catalytic activity of one type of Cu-MOF[Cu3(BTC)2(H2O)3, HKUST-1]. The color of o-phenylenediamine (OPD) can be changed significantly because of the oxidation of H2O2 catalyzed by HKUST-1. As a result, H2O2 and DA were detected rapidly and sensitively by our system. Under the optimum conditions, two linear relationships between the intensity of absorption peak at 415nm and the concentration of H2O2 (from 10 to 50 mmol/L and from 50 to 100 mmol/L, R=0.9947 and 0.9995) were obtained with the detection limit of 1.29 mmol/L. Besides, DA can resist the oxidation of OPD from H2O2, this platform was further used for rapid detection of DA with two linear ranges (from 0.25 to 5μmol/L and from 2.5 to 25μmol/L, R=0.9783 and 0.9705), and the detection limit was 0.262 μmol/L. Therefore, this work may broaden the applications of Cu-MOFs in biological molecular catalysis and biosensing fields.
2017, 80(1): 53-58
Abstract:
In this work, manganese dioxide (MnO2) nanotube arrays are fabricated by using polydopamine coated-zinc oxide nanorod supported on quartz plates as template, followed by potassium permanganate reduction by polydopamine and the ZnO template removal. Characterization results showed that as-fabricated MnO2 nanotubes have well-defined tube morphology and strongly adhere to the substrate. The formed MnO2 is amorphous. Polydopamine coated zinc oxide nanostructure as template exhibits several advantages, for example, it possesses diverse surface morphologies, and is easy to be synthesized and removed; the formation of polydopamine is also facile. These advantages might pave the way towards simple and facile fabrication of various MnO2 nanostructures.
In this work, manganese dioxide (MnO2) nanotube arrays are fabricated by using polydopamine coated-zinc oxide nanorod supported on quartz plates as template, followed by potassium permanganate reduction by polydopamine and the ZnO template removal. Characterization results showed that as-fabricated MnO2 nanotubes have well-defined tube morphology and strongly adhere to the substrate. The formed MnO2 is amorphous. Polydopamine coated zinc oxide nanostructure as template exhibits several advantages, for example, it possesses diverse surface morphologies, and is easy to be synthesized and removed; the formation of polydopamine is also facile. These advantages might pave the way towards simple and facile fabrication of various MnO2 nanostructures.
2017, 80(1): 59-63
Abstract:
In this work graphene oxide was covalently modified by ruthenium trisbipyridine through non-conjugative and conjugative bridges respectively. The obtained ruthenium trisbipyridine-graphene oxide (Ru (Ⅱ)-GO) nanocomposites were characterized by IR, UV-Vis, energy dispersive X-ray spectrum (EDS), TEM and XRD in detail. Especially, their photovoltaic properties were detected by photocurrent response measurements. Under visible light irradiation, the Ru (Ⅱ)-GO with conjugative bridge exhibited a large photocurrent density of 3.5 μA/cm2, which was 3.3 times as that of the Ru (Ⅱ)-GO with non-conjugative bridge, indicating that the bridge structures have significant influence on the photovoltaic properties of Ru (Ⅱ)-GO nanocomposites.
In this work graphene oxide was covalently modified by ruthenium trisbipyridine through non-conjugative and conjugative bridges respectively. The obtained ruthenium trisbipyridine-graphene oxide (Ru (Ⅱ)-GO) nanocomposites were characterized by IR, UV-Vis, energy dispersive X-ray spectrum (EDS), TEM and XRD in detail. Especially, their photovoltaic properties were detected by photocurrent response measurements. Under visible light irradiation, the Ru (Ⅱ)-GO with conjugative bridge exhibited a large photocurrent density of 3.5 μA/cm2, which was 3.3 times as that of the Ru (Ⅱ)-GO with non-conjugative bridge, indicating that the bridge structures have significant influence on the photovoltaic properties of Ru (Ⅱ)-GO nanocomposites.
2017, 80(1): 64-68
Abstract:
Eight novel compounds of 3-[2-Substituted Aryl-1, 5-Benzodiazepin-4-yl]propionate were efficiently synthesized by the Knoevenagel reaction, nucleophilic addition reaction and dehydration cyclization reaction, using substituted aromatic aldehyde and ethyl levulinate as starting material. The structures of these compounds were determined by 1H NMR, 13C NMR, IR, MS and X-ray single crystal diffraction. The exhaustive researches on the synthetic reaction of the class of compounds were carried out, and the reaction mechanism has been unequivocally established in this paper.
Eight novel compounds of 3-[2-Substituted Aryl-1, 5-Benzodiazepin-4-yl]propionate were efficiently synthesized by the Knoevenagel reaction, nucleophilic addition reaction and dehydration cyclization reaction, using substituted aromatic aldehyde and ethyl levulinate as starting material. The structures of these compounds were determined by 1H NMR, 13C NMR, IR, MS and X-ray single crystal diffraction. The exhaustive researches on the synthetic reaction of the class of compounds were carried out, and the reaction mechanism has been unequivocally established in this paper.
2017, 80(1): 69-76
Abstract:
5-Halogenated isatins (1a~1d) were first N-alkylated to give the corresponding 1-alkyl-5-halogenated isatins (2a~2t). Subsequently, 1a~1d and 2a~2t were condensated with o-diaminobenzene in acetic acid to afford a series of 6H-indolo[2, 3-b]quinoxaline derivatives (3a~3x) with yields of 65%~88%. Among them, ten compounds were unreported in the literatures and their structures were confirmed by IR, 1H NMR, 13C NMR spectra and HRMS.
5-Halogenated isatins (1a~1d) were first N-alkylated to give the corresponding 1-alkyl-5-halogenated isatins (2a~2t). Subsequently, 1a~1d and 2a~2t were condensated with o-diaminobenzene in acetic acid to afford a series of 6H-indolo[2, 3-b]quinoxaline derivatives (3a~3x) with yields of 65%~88%. Among them, ten compounds were unreported in the literatures and their structures were confirmed by IR, 1H NMR, 13C NMR spectra and HRMS.
2017, 80(1): 77-83
Abstract:
A series of halogen atom substituted chalcones and their derivatives were synthesized. All of them were evaluated for their antioxidant activities and inhibitory activities against mushroom tyrosinase. The results showed that some of them exhibit significant tyrosinase inhibitory activities, three compounds exhibit more potent inhibitory activities than the reference standard inhibitor. Especially, the thiosemicarbazide Schiff base of 4-bromochalcone (compound 9) has the most potent tyrosinase inhibitory activity with an IC50 value of 2.02 μmol/L. In addition, some compounds showed certain antioxidant activities. The inhibition mechanism analysis of compound 9 showed that the inhibitory effect of the compound on the tyrosinase was irreversible. Preliminary structure activity relationships' (SARs) analysis suggested that further development of such compounds might be of interest. Docking studies showed sulfur atom and phenyl ring B could form π bond with residue of the tyrosinase, and the amino could form hydrogen bond with HIS295.
A series of halogen atom substituted chalcones and their derivatives were synthesized. All of them were evaluated for their antioxidant activities and inhibitory activities against mushroom tyrosinase. The results showed that some of them exhibit significant tyrosinase inhibitory activities, three compounds exhibit more potent inhibitory activities than the reference standard inhibitor. Especially, the thiosemicarbazide Schiff base of 4-bromochalcone (compound 9) has the most potent tyrosinase inhibitory activity with an IC50 value of 2.02 μmol/L. In addition, some compounds showed certain antioxidant activities. The inhibition mechanism analysis of compound 9 showed that the inhibitory effect of the compound on the tyrosinase was irreversible. Preliminary structure activity relationships' (SARs) analysis suggested that further development of such compounds might be of interest. Docking studies showed sulfur atom and phenyl ring B could form π bond with residue of the tyrosinase, and the amino could form hydrogen bond with HIS295.
2017, 80(1): 84-88
Abstract:
Thiazole[3, 2-a]pyrimidine derivatives have a variety of biological activities, but their applications are limited because of their poor solubilities. Thiazole[3, 2-a]pyrimidine derivative L has been successfully synthesized by nucleophilic substitution of 7-(3-aminobenzofuran-2-yl) thiazolo[3, 2-a]pyrimidin-5-one as aromatic ring matrix with triethylene glycol monomethyl ether. The structure of L was characterized by NMR and high resolution mass spectrum. Compound L can be used for highly selective recognition of Fe3+ with a fluorescence "ON-OFF" response in buffered aqueous solution (HEPES 1×10-3 mol/L, pH=6.4). The fluorescent probe L displays a wide usable pH range from 3.4 to 6.4, non-interference from other metal ions and the low limit of detection.
Thiazole[3, 2-a]pyrimidine derivatives have a variety of biological activities, but their applications are limited because of their poor solubilities. Thiazole[3, 2-a]pyrimidine derivative L has been successfully synthesized by nucleophilic substitution of 7-(3-aminobenzofuran-2-yl) thiazolo[3, 2-a]pyrimidin-5-one as aromatic ring matrix with triethylene glycol monomethyl ether. The structure of L was characterized by NMR and high resolution mass spectrum. Compound L can be used for highly selective recognition of Fe3+ with a fluorescence "ON-OFF" response in buffered aqueous solution (HEPES 1×10-3 mol/L, pH=6.4). The fluorescent probe L displays a wide usable pH range from 3.4 to 6.4, non-interference from other metal ions and the low limit of detection.
2017, 80(1): 89-94
Abstract:
In Escherichia coli, cell division occurs when Z-ring forms at the mid-site of cell through polymerization of FtsZ. The Z-ring formation is inhibited by MinC, resulting in regulation of cell division. Herein, minC and ftsZ were cloned into vectors containing different antibiotics to express recombinant proteins, then MinC and FtsZ were purified by affinity chromatography and gel filtration chromatography. Two different methods, binding MinC and FtsZ after being expressed and purified respectively, and co-transformation, co-expression and co-purification of MinC and FtsZ were tried to gain MinC/FtsZ complex for crystal screen. Results showed that with appropriate conditions, through the way of binding MinC and FtsZ after being expressed and purified respectively, MinC/FtsZ complex were in the proportion of 1:1. The addition of GTP and MgCl2 helped improve the protein state of MinC/FtsZ complex, and needle shape of MinC/FtsZ complex was observed after crystal screen. This study provides experimental basis for structural analysis of MinC/FtsZ complex.
In Escherichia coli, cell division occurs when Z-ring forms at the mid-site of cell through polymerization of FtsZ. The Z-ring formation is inhibited by MinC, resulting in regulation of cell division. Herein, minC and ftsZ were cloned into vectors containing different antibiotics to express recombinant proteins, then MinC and FtsZ were purified by affinity chromatography and gel filtration chromatography. Two different methods, binding MinC and FtsZ after being expressed and purified respectively, and co-transformation, co-expression and co-purification of MinC and FtsZ were tried to gain MinC/FtsZ complex for crystal screen. Results showed that with appropriate conditions, through the way of binding MinC and FtsZ after being expressed and purified respectively, MinC/FtsZ complex were in the proportion of 1:1. The addition of GTP and MgCl2 helped improve the protein state of MinC/FtsZ complex, and needle shape of MinC/FtsZ complex was observed after crystal screen. This study provides experimental basis for structural analysis of MinC/FtsZ complex.
2017, 80(1): 94-98, 107
Abstract:
A new nontoxic and harmless superabsorbent resin was prepared through free-radical polymerization in aqueous solution using starch, 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and methacryloyloxyethyl trimethyl ammonium chloride as raw materials. The resin was characterized by FTIR, SEM and TG analysis. The absorption capacities of as-prepared starch/AMPS/DMC resin for Cu2+ and Ni2+ was examined. Cu2+ and Ni2+ can be completely absorbed by superabsorbent resin within 2~3 min when the concentration of CuSO4 and NiSO4 are 2 g/L. The isothermal adsorption equation shows that Freundlich equation can better describes the adsorption behavior.
A new nontoxic and harmless superabsorbent resin was prepared through free-radical polymerization in aqueous solution using starch, 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and methacryloyloxyethyl trimethyl ammonium chloride as raw materials. The resin was characterized by FTIR, SEM and TG analysis. The absorption capacities of as-prepared starch/AMPS/DMC resin for Cu2+ and Ni2+ was examined. Cu2+ and Ni2+ can be completely absorbed by superabsorbent resin within 2~3 min when the concentration of CuSO4 and NiSO4 are 2 g/L. The isothermal adsorption equation shows that Freundlich equation can better describes the adsorption behavior.
2017, 80(1): 99-103
Abstract:
The calcium oxide modified kaolin was characterized by XRD, SEM, FT-IR, and applied in landfill leachate treatment. The effects of the dosage, the initial solution pH, adsorption time on the removal of ammonia nitrogen, as well as the adsorption mechanism were discussed. The results showed that the main products of calcium oxide modified kaolin is cementitious material hydrate (calcium silicoaluminate and Al-containing C-S-H), and its shape is a honeycomb. The removal efficiencies of 160 g/L adsorbent to landfill leachate with 3520 mg/L ammonia, pH 7.53~7.80 can reach 82.6%, the adsorption capacity was 18.2 mg/g after absorbed 60 minutes. The equilibrium isotherm and kinetics models showed that the adsorption of ammonia by calcium oxide modified kaolin agrees with Langmuir equation and quasi-second-order equation well, and the correlation coefficients are 0.9723, 0.9989, and the adsorption progress includes intra-particle diffusion and the boundary layer diffusion.
The calcium oxide modified kaolin was characterized by XRD, SEM, FT-IR, and applied in landfill leachate treatment. The effects of the dosage, the initial solution pH, adsorption time on the removal of ammonia nitrogen, as well as the adsorption mechanism were discussed. The results showed that the main products of calcium oxide modified kaolin is cementitious material hydrate (calcium silicoaluminate and Al-containing C-S-H), and its shape is a honeycomb. The removal efficiencies of 160 g/L adsorbent to landfill leachate with 3520 mg/L ammonia, pH 7.53~7.80 can reach 82.6%, the adsorption capacity was 18.2 mg/g after absorbed 60 minutes. The equilibrium isotherm and kinetics models showed that the adsorption of ammonia by calcium oxide modified kaolin agrees with Langmuir equation and quasi-second-order equation well, and the correlation coefficients are 0.9723, 0.9989, and the adsorption progress includes intra-particle diffusion and the boundary layer diffusion.
2017, 80(1): 104-107
Abstract:
In order to improve the corrosion resistant properties of nickel titanium shape memory alloys, graphene was in-situ synthesized by chemical vapor deposition on the surface of nickel titanium. The structures and surface morphologies of prepared materials were characterized by X-ray photoelectron spectroscopy, Raman spectroscopy and scanning electron microscope. Furthermore, in the artificial saliva environment the influences of graphene on the corrosion speed, cytotoxicity and metal release of shape memory alloy were studied. The results showed that graphene between metal matrix and corrosive medium plays a physical shielding role, significantly reducing the corrosion rate of metal matrix and protecting the nickel titanium alloy.
In order to improve the corrosion resistant properties of nickel titanium shape memory alloys, graphene was in-situ synthesized by chemical vapor deposition on the surface of nickel titanium. The structures and surface morphologies of prepared materials were characterized by X-ray photoelectron spectroscopy, Raman spectroscopy and scanning electron microscope. Furthermore, in the artificial saliva environment the influences of graphene on the corrosion speed, cytotoxicity and metal release of shape memory alloy were studied. The results showed that graphene between metal matrix and corrosive medium plays a physical shielding role, significantly reducing the corrosion rate of metal matrix and protecting the nickel titanium alloy.
2017, 80(1): 108-111
Abstract:
Carbon microspheres prepared by hydrothermal method were used as template to prepare LaCoxFe1-xO3 (x=0.1, 0.2, 0.3, 0.6, 0.9) catalysts. As-prepared catalysts were characterized by XRD, BET, H2-TPR and SEM techniques, and their catalytic activities for methane combustion were evaluated. With carbon microspheres as template and doped with different proportion of Co2+, a complete perovskite crystal was formed after calcining at 400℃ and 700℃. The specific surface area of catalysts increased gradually with increasing doping amount of Co2+. The structure and catalytic activities are also different while altering the doping amount of Co2+. The catalyst LaCo0.2Fe0.8O3 shows an excellent catalytic activity for methane combustion, the conversion rates of 10% and 90% are obtained at 448℃ and 640℃, respectively.
Carbon microspheres prepared by hydrothermal method were used as template to prepare LaCoxFe1-xO3 (x=0.1, 0.2, 0.3, 0.6, 0.9) catalysts. As-prepared catalysts were characterized by XRD, BET, H2-TPR and SEM techniques, and their catalytic activities for methane combustion were evaluated. With carbon microspheres as template and doped with different proportion of Co2+, a complete perovskite crystal was formed after calcining at 400℃ and 700℃. The specific surface area of catalysts increased gradually with increasing doping amount of Co2+. The structure and catalytic activities are also different while altering the doping amount of Co2+. The catalyst LaCo0.2Fe0.8O3 shows an excellent catalytic activity for methane combustion, the conversion rates of 10% and 90% are obtained at 448℃ and 640℃, respectively.
2017, 80(1): 112-115
Abstract:
Cd2+ in water was pre-concentrated by the diffusive gradients in thin-films (DGT) technique with sodium alginate (SA) as binding phase (SA DGT) and measured by atomic absorption spectrometry (ASS). The recoveries of Cd2+ in the synthetic solutions measured by the DGT-ASS method were 95.6%~102.7%, with RSD 1.5%~3.1%. The DGT-labile fractions of Cd2+ in a river and a lake were 22.46% and 15.19%, respectively. The enrichment factor of Cd2+ pre-concentrated by SA DGT was 20 (deployment time 48h), and the detection limit of the analytical method can be significantly reduced. Therefore, the DGT-AAS method can be used to measure trace Cd2+ in water.
Cd2+ in water was pre-concentrated by the diffusive gradients in thin-films (DGT) technique with sodium alginate (SA) as binding phase (SA DGT) and measured by atomic absorption spectrometry (ASS). The recoveries of Cd2+ in the synthetic solutions measured by the DGT-ASS method were 95.6%~102.7%, with RSD 1.5%~3.1%. The DGT-labile fractions of Cd2+ in a river and a lake were 22.46% and 15.19%, respectively. The enrichment factor of Cd2+ pre-concentrated by SA DGT was 20 (deployment time 48h), and the detection limit of the analytical method can be significantly reduced. Therefore, the DGT-AAS method can be used to measure trace Cd2+ in water.
2017, 80(1): 116-119
Abstract:
The equipment based on field asymmetric waveform ion mobility spectrometry (FAIMS) chip was established to detect acetone, phenol, cyclohexane and their mixtures successfully. Gas of acetone, phenol and cyclohexane was vapored by trace gas generator. The ratio of air and organic gas was adjusted by the mass flow controller to generate organic gas of various concentrations. The mixture was sent into the chip core, then the signal was adopted and transformed into spectrograph. Organic gas was confirmed and detected by comparing the spectrograph of background with the spectrograph of organic gas. The test results showed there was a relationship in direct proportion between the concentration of organic gas and the signal value. The organics in mixtures could be determined separately by regulating the positive and negative mode of alternating electric field and adjusting the compensation voltage.
The equipment based on field asymmetric waveform ion mobility spectrometry (FAIMS) chip was established to detect acetone, phenol, cyclohexane and their mixtures successfully. Gas of acetone, phenol and cyclohexane was vapored by trace gas generator. The ratio of air and organic gas was adjusted by the mass flow controller to generate organic gas of various concentrations. The mixture was sent into the chip core, then the signal was adopted and transformed into spectrograph. Organic gas was confirmed and detected by comparing the spectrograph of background with the spectrograph of organic gas. The test results showed there was a relationship in direct proportion between the concentration of organic gas and the signal value. The organics in mixtures could be determined separately by regulating the positive and negative mode of alternating electric field and adjusting the compensation voltage.
