Amantadine （AMA） is an anti-viral drug used in apiculture to protect honeybee against the sacbrood virus （Morator aetatulae）. This study described a reliable high-performance liquid chromatographic （HPLC） method...Amantadine （AMA） is an anti-viral drug used in apiculture to protect honeybee against the sacbrood virus （Morator aetatulae）. This study described a reliable high-performance liquid chromatographic （HPLC） method for analyzing AMA in honey using a solid-phase extraction （SPE） cartridge （Plexa PCX） for purification, 4-fluoro-7- nitro-2,1,3-benzoxadiazole （NBD-F） as a pre-column derivatization agent, and fluorometric detection （λex =470 nm, λem=530 nm）. The chromatographic separation was performed on an XDB C18 column （150×4.6 mm i.d.） using 0.1% trifluoroacetic acid/acetonitrile （35 ; 65, V/V） as the mobile phase at a flow rate of 1.0 mLomin 1 with a run time of 20 min. Under these optimal conditions, a linear relationship was observed in the range of 0.025--1.0μg·mL-1 with a good correlation coefficient （0.998） and low limit of detection （0.0080 μg·g-1）, the recoveries were all above 90%, and the intra-day and inter-day precision （RSD） ranged from 3.4%--5.1%.展开更多
This article focused on the influences of fulvic acid and humic acid on aluminum speciation in drinking water. Factors including the concentration of residual chlorine and pH value had been concerned. Aluminum species...This article focused on the influences of fulvic acid and humic acid on aluminum speciation in drinking water. Factors including the concentration of residual chlorine and pH value had been concerned. Aluminum species investigated in the experiments included inorganic mononuclear, organic mononuclear, mononuclear, polymer, soluble, and suspended forms. It was found that the effects of fulvic acid and humic acid on aluminum speciation depended mainly on their molecular weight. Fulvic acid with molecular weight less than 5000 Dalton had little influence on aluminum speciation; while fulvic acid with molecular weight larger than 5000 Dalton and humic acid would increase the concentration of soluble aluminum significantly even at concentration below 0.5 mg/L （calculated as TOC）. Aluminum species, in the present of fulvic acid with molecular weight larger than 5000 Dalton and humic acid, were more stable than that in the present of fluvic acid with molecular mass less than 5000 Dalton, and varied little with reaction time. Within pH range 6.5-7.5, soluble aluminum increased notably in water with organic matter. As the concentration of residual chlorine increased, the effects of fulvic acid and humic acid became weak. The reactions between humic acid, fulvic acid with large molecular weight, and aluminum were considered to be a multi-dentate coordination process. With the consideration of aluminum bioavailability, reducing the concentration of fulvic acid and humic acid and keeping the pH value among 6.5-7.5 were recommended during drinking water treatment.展开更多
A highly sensitive sensor for determination of carbamate pesticides based rhodamine B（RB） modified silver nanoparticle（RB-AgNPs） was developed.Compared with the classical method,it combined colorimetric with fluor...A highly sensitive sensor for determination of carbamate pesticides based rhodamine B（RB） modified silver nanoparticle（RB-AgNPs） was developed.Compared with the classical method,it combined colorimetric with fluorescence for detecting carbamate pesticides in complex solutions.Carbamate pesticides can inhibit the activity of acetylcholinesterase（AChE）,thus preventing the generation of thiocholine.On the other hand,thioncholine can transform the yellow RB-AgNPs solutions gray color and unquenches the fluorescence of RB simultaneously.Once the activity of AChE was inhibited by the pesticide,the color of the RB-AgNPs solution remains yellow and the fluorescence of RB molecules remains quenched.Under optimized experimental conditions,carbaryl was detected in a concentration range from 0.1 ng/L to 8.0ng/L with a detection limit of 0.023 ng/L（it was detected by fluorescence spectra）.This simple method is suitable for determination of carbamate pesticides in complex samples,such as tomato,apple and river water.展开更多
Effects of aluminum on water distribution system and human health mainly attribute to its speciation in drinking water. Laboratory experiments were performed to investigate factors that may influence aluminum speciati...Effects of aluminum on water distribution system and human health mainly attribute to its speciation in drinking water. Laboratory experiments were performed to investigate factors that may influence aluminum speciation in water supply system. The concentration of soluble aluminum and its transformation among other aluminum species were mainly controlled by kinetics processes of related reactions. Total aluminum concentration had a notable effect on the concentrations of mononuclear and soluble aluminum in the first 4 day; then its effect became weak. At pH above 7.50, both fluoride and orthophosphate had little effect on aluminum speciation; while, when the solution pH was below 7.50, the concentrations of mononuclear and soluble aluminum were proportional to the concentration of fluoride and inversely proportional to the concentration of orthophosphate. Both mononuclear and polynuclear silicic acids could complex with mononuclear aluminum by forming soluble aluminosilicates. In addition, the adding sequence of orthophosphate and aluminum into drinking water would also affect the distribution of aluminum species in the first 4 day. In order to minimize aluminum bioavailability in drinking water, it was suggested that orthophosphate should be added prior to coagulant process, and that the concentrations of fluoride and silicic acids should be controlled below 2.0 and 25 mg/L, respectively, prior to the treatment. The solution pH in coagulation and filtration processes should be controlled in the range of 6.50-7.50.展开更多
A novel and very simple colorimetric and fluorometric method for selectively sensing F^- was proposed based on 4-bromo-2,6- bis（hydroxymethyl）phenol（BBHMP）,which is a simple and available phenolic receptor the abs...A novel and very simple colorimetric and fluorometric method for selectively sensing F^- was proposed based on 4-bromo-2,6- bis（hydroxymethyl）phenol（BBHMP）,which is a simple and available phenolic receptor the absence of any special chromophoric function and with over wide range of anions（Cl^-,Br^-,I^-,AcO^-,HSO4^-,NO3^- and BzO^-） in DMSO media.The colorimetric method is described for naked-eye detection of F^- in the presence of the BBHMP.The BBHMP was found to show selective and sensitive fluorescence quenching response toward fluoride over than Cl^-,Br^-,I^-,AcO^-,HSO4^-,NO3^- and BzO^-.展开更多
Herein,a novel method for fl uorometric detection of soybean trypsin inhibitor(SBTI)activity based on a water-soluble poly(diphenylacetylene)derivative was reported.Fluorescence quenching of the polymer via p-nitroani...Herein,a novel method for fl uorometric detection of soybean trypsin inhibitor(SBTI)activity based on a water-soluble poly(diphenylacetylene)derivative was reported.Fluorescence quenching of the polymer via p-nitroaniline,produced from the trypsin-catalyzed decomposition of N-benzoyl-DL-arginine-4-nitroanilide hydrochloride(L-BAPA),was well described using the Stern-Volmer equation.SBTI activity was quantitatively assessed based on changes in the fl uorescence intensity of the polymer.This strategy has several advantages,such as high sensitivity and ease of operation.Moreover,its applicability to other biochemical analyses is promising.展开更多
A series of carb on nano particles(CNPs)with emissi on wavele ngth ranging from 483 to 525 nm were prepared by hydrothermal treatme nt of poly-3-thiopheneacetic acid(PTA)and NaOH.The emission wavelength and surface ox...A series of carb on nano particles(CNPs)with emissi on wavele ngth ranging from 483 to 525 nm were prepared by hydrothermal treatme nt of poly-3-thiopheneacetic acid(PTA)and NaOH.The emission wavelength and surface oxidation degree of CNPs were shown to be controllable by simply adjusti ng NaOH concentration.These CNPs prese nted obvious fluoresce nee spectral response toward copper ions(Cu^2+)through static quenching caused synergistically by electron transfer and inner filter effect.The O-and S-containing groups on the surface of CNPs were dem on strated to be resp on sible for their outsta nding sensing performa nee.Based on that,a CN Ps-based ratiometric fluoresce nt probe for Cu^2+with a high fluoresce nee quenching rate constant of 1.4×10^5 L/mol and a short resp onse time(10 s)was developed.Their practical applications in detecting Cu^2+in pond water and living cells were also dem on strated.展开更多
Terbium and N,N′,N' tri(3,5 diamino benzenesulfonyl) 1,4,7 triazacyclononane (TDABS Tacn) form a stable chelate having a 1∶1 molar ratio in dilute aqueous solution. The fluorescence property of the chelate ...Terbium and N,N′,N' tri(3,5 diamino benzenesulfonyl) 1,4,7 triazacyclononane (TDABS Tacn) form a stable chelate having a 1∶1 molar ratio in dilute aqueous solution. The fluorescence property of the chelate was studied under the experimental conditions (pH 8.4 in H 3BO 3 KCl NaOH buffer, λ EX =309 nm, λ EM =374 nm). The fluorescence intensity is a linear function of concentration in the range of 5.0×10 -6 to 4.2×10 -4 mol/L for terbium. The relative standard deviation is less than ±2.0%. When tolerable amount of other metal ions were added to the solution of terbium chelate, the fluorescence intensity can be determined without interference. These results suggest that aromatic armed polyazamacrocycle can be used for the terbium determination.展开更多
Glycine can react with acetylacetone and formaldehyde in HAc-NaAc buffer to give a product which can emit strong fluorescence.A Fluorometric determination of glycine in beverage was developed in the present work.The l...Glycine can react with acetylacetone and formaldehyde in HAc-NaAc buffer to give a product which can emit strong fluorescence.A Fluorometric determination of glycine in beverage was developed in the present work.The linear range was 0.1-200μg·mL-1.Experimental conditions such as pH of the solution,reaction temperature and reaction time were optimized.Effect of coexist compound was also discussed.The method can be applied to the determination of glycine in beverages.The recovery of the method is 91.8-107.5%.展开更多
Tetra(amino)azacalix[4]arene skeleton was functionalized at the bridging NH sites using various aromatic aldehydes via formation of imidazobenzimidazole fused heterocycles.X-ray single crystal analysis revealed distor...Tetra(amino)azacalix[4]arene skeleton was functionalized at the bridging NH sites using various aromatic aldehydes via formation of imidazobenzimidazole fused heterocycles.X-ray single crystal analysis revealed distorted 1,3-alternate conformations for the resulting macrocycles.Anthracenyl and pyrenyl modified imidazobenzimidazole fused aza-calix[4]arenes existed as dimers in the solid state,associated mainly through-stacking interactions between the planar polycyclic fluorophores.The tetrapyrenyl modified product was further used as a Zn^(2+)-selective sensor,which showed naked-eye detected color change and enhanced excimer emission.The stoichiometry between the sensor and Zn2+was determined to be 1:1 and the association constant was 1.1×10^(5)L/mol.The sensing process was highly selective and showed strong anti-interference with presence of other cations.The UV-vis spectral changes in the sensing process were completely reversible by alternate addition of Zn^(2+) and F^(-),showing an efficient“on-off-on”result.展开更多
Studies were performed to determine the extent of nuclear DNA degradation induced by iron, iron-ascorbate, or iron-bleomycin under aerobic conditions in a model system using isolated rat liver nuclei. The effects of f...Studies were performed to determine the extent of nuclear DNA degradation induced by iron, iron-ascorbate, or iron-bleomycin under aerobic conditions in a model system using isolated rat liver nuclei. The effects of five antioxidants (catalase, superoxide dismutase, dimethyl sulfoxide, glutathione and diallyl sulfide) on this oxidative nuclear damage were also investigated. At the 0.05 level for statistical significance, iron induced concentration-dependent DNA degradation, and this effect was enhanced by ascorbate and bleomycin. The antioxidants catalase, dimethyl sulfoxide, and diallyl sulfide significantly reduced the iron-ascorbate-induced DNA damage, whereas superoxide dismutase and dimethyl sulfoxide significantly reduced iron-bleomycin-induced damage. Glutathione significantly increased the iron-bleomycin-induced DNA damage. These results suggest that the reactive oxygen species generated by iron, iron-ascorbate, and iron-bleomycin are responsible for the DNA strand breaks in isolated rat liver nuclei.展开更多
Anew opticalfiberfluorometricthermometerbased onthetemperature dependence ofthefluorescencelifetime of phosphoris described. The phase-locked detection (PLD) system is used to measure fluorescencelifetime. The charact...Anew opticalfiberfluorometricthermometerbased onthetemperature dependence ofthefluorescencelifetime of phosphoris described. The phase-locked detection (PLD) system is used to measure fluorescencelifetime. The characteristics ofthermometerare discussed and the experimentresults are given.展开更多
文摘Amantadine （AMA） is an anti-viral drug used in apiculture to protect honeybee against the sacbrood virus （Morator aetatulae）. This study described a reliable high-performance liquid chromatographic （HPLC） method for analyzing AMA in honey using a solid-phase extraction （SPE） cartridge （Plexa PCX） for purification, 4-fluoro-7- nitro-2,1,3-benzoxadiazole （NBD-F） as a pre-column derivatization agent, and fluorometric detection （λex =470 nm, λem=530 nm）. The chromatographic separation was performed on an XDB C18 column （150×4.6 mm i.d.） using 0.1% trifluoroacetic acid/acetonitrile （35 ; 65, V/V） as the mobile phase at a flow rate of 1.0 mLomin 1 with a run time of 20 min. Under these optimal conditions, a linear relationship was observed in the range of 0.025--1.0μg·mL-1 with a good correlation coefficient （0.998） and low limit of detection （0.0080 μg·g-1）, the recoveries were all above 90%, and the intra-day and inter-day precision （RSD） ranged from 3.4%--5.1%.
基金supported by the National Natural Science Foundation of China (No.50838005)the Changjiang Scholars and Innovative Research Team in University(No.IRT0853)the American Aluminum Foundation
文摘This article focused on the influences of fulvic acid and humic acid on aluminum speciation in drinking water. Factors including the concentration of residual chlorine and pH value had been concerned. Aluminum species investigated in the experiments included inorganic mononuclear, organic mononuclear, mononuclear, polymer, soluble, and suspended forms. It was found that the effects of fulvic acid and humic acid on aluminum speciation depended mainly on their molecular weight. Fulvic acid with molecular weight less than 5000 Dalton had little influence on aluminum speciation; while fulvic acid with molecular weight larger than 5000 Dalton and humic acid would increase the concentration of soluble aluminum significantly even at concentration below 0.5 mg/L （calculated as TOC）. Aluminum species, in the present of fulvic acid with molecular weight larger than 5000 Dalton and humic acid, were more stable than that in the present of fluvic acid with molecular mass less than 5000 Dalton, and varied little with reaction time. Within pH range 6.5-7.5, soluble aluminum increased notably in water with organic matter. As the concentration of residual chlorine increased, the effects of fulvic acid and humic acid became weak. The reactions between humic acid, fulvic acid with large molecular weight, and aluminum were considered to be a multi-dentate coordination process. With the consideration of aluminum bioavailability, reducing the concentration of fulvic acid and humic acid and keeping the pH value among 6.5-7.5 were recommended during drinking water treatment.
基金financially supported by the Open Funds of the State Key Laboratory of Electroanalytical Chemistry (No. SKLEAC201602)
文摘A highly sensitive sensor for determination of carbamate pesticides based rhodamine B（RB） modified silver nanoparticle（RB-AgNPs） was developed.Compared with the classical method,it combined colorimetric with fluorescence for detecting carbamate pesticides in complex solutions.Carbamate pesticides can inhibit the activity of acetylcholinesterase（AChE）,thus preventing the generation of thiocholine.On the other hand,thioncholine can transform the yellow RB-AgNPs solutions gray color and unquenches the fluorescence of RB simultaneously.Once the activity of AChE was inhibited by the pesticide,the color of the RB-AgNPs solution remains yellow and the fluorescence of RB molecules remains quenched.Under optimized experimental conditions,carbaryl was detected in a concentration range from 0.1 ng/L to 8.0ng/L with a detection limit of 0.023 ng/L（it was detected by fluorescence spectra）.This simple method is suitable for determination of carbamate pesticides in complex samples,such as tomato,apple and river water.
基金supported by the National Natural Science Foundation of China (No.50238020)the American Aluminum Foundation
文摘Effects of aluminum on water distribution system and human health mainly attribute to its speciation in drinking water. Laboratory experiments were performed to investigate factors that may influence aluminum speciation in water supply system. The concentration of soluble aluminum and its transformation among other aluminum species were mainly controlled by kinetics processes of related reactions. Total aluminum concentration had a notable effect on the concentrations of mononuclear and soluble aluminum in the first 4 day; then its effect became weak. At pH above 7.50, both fluoride and orthophosphate had little effect on aluminum speciation; while, when the solution pH was below 7.50, the concentrations of mononuclear and soluble aluminum were proportional to the concentration of fluoride and inversely proportional to the concentration of orthophosphate. Both mononuclear and polynuclear silicic acids could complex with mononuclear aluminum by forming soluble aluminosilicates. In addition, the adding sequence of orthophosphate and aluminum into drinking water would also affect the distribution of aluminum species in the first 4 day. In order to minimize aluminum bioavailability in drinking water, it was suggested that orthophosphate should be added prior to coagulant process, and that the concentrations of fluoride and silicic acids should be controlled below 2.0 and 25 mg/L, respectively, prior to the treatment. The solution pH in coagulation and filtration processes should be controlled in the range of 6.50-7.50.
文摘A novel and very simple colorimetric and fluorometric method for selectively sensing F^- was proposed based on 4-bromo-2,6- bis（hydroxymethyl）phenol（BBHMP）,which is a simple and available phenolic receptor the absence of any special chromophoric function and with over wide range of anions（Cl^-,Br^-,I^-,AcO^-,HSO4^-,NO3^- and BzO^-） in DMSO media.The colorimetric method is described for naked-eye detection of F^- in the presence of the BBHMP.The BBHMP was found to show selective and sensitive fluorescence quenching response toward fluoride over than Cl^-,Br^-,I^-,AcO^-,HSO4^-,NO3^- and BzO^-.
基金The authors appreciate the support from the Zhe-jiang Province Lingyan Key R&D Project(No.2022C01177)the Zhejiang Administration for Market Regulation Eyas Program Cultiva-tion Project(No.CY2022355).
文摘Herein,a novel method for fl uorometric detection of soybean trypsin inhibitor(SBTI)activity based on a water-soluble poly(diphenylacetylene)derivative was reported.Fluorescence quenching of the polymer via p-nitroaniline,produced from the trypsin-catalyzed decomposition of N-benzoyl-DL-arginine-4-nitroanilide hydrochloride(L-BAPA),was well described using the Stern-Volmer equation.SBTI activity was quantitatively assessed based on changes in the fl uorescence intensity of the polymer.This strategy has several advantages,such as high sensitivity and ease of operation.Moreover,its applicability to other biochemical analyses is promising.
基金This work was supported by the General Research Fund of Hong Kong(Nos.CityU 11306717,and CityU 11338516)the National Natural Science Foundation of China(Nos.61720106014 and 61805287)+2 种基金National Science Foundation of Hunan Province,China(Nos.2018JJ3632 and 2019JJ50824)Basic Research Foundation of Shenzhen Science and Technology Innovation(Nos.JCYJ20180307151245919)the Fundamental Research Funds for the Central Universities(No.202045002).
文摘A series of carb on nano particles(CNPs)with emissi on wavele ngth ranging from 483 to 525 nm were prepared by hydrothermal treatme nt of poly-3-thiopheneacetic acid(PTA)and NaOH.The emission wavelength and surface oxidation degree of CNPs were shown to be controllable by simply adjusti ng NaOH concentration.These CNPs prese nted obvious fluoresce nee spectral response toward copper ions(Cu^2+)through static quenching caused synergistically by electron transfer and inner filter effect.The O-and S-containing groups on the surface of CNPs were dem on strated to be resp on sible for their outsta nding sensing performa nee.Based on that,a CN Ps-based ratiometric fluoresce nt probe for Cu^2+with a high fluoresce nee quenching rate constant of 1.4×10^5 L/mol and a short resp onse time(10 s)was developed.Their practical applications in detecting Cu^2+in pond water and living cells were also dem on strated.
文摘Terbium and N,N′,N' tri(3,5 diamino benzenesulfonyl) 1,4,7 triazacyclononane (TDABS Tacn) form a stable chelate having a 1∶1 molar ratio in dilute aqueous solution. The fluorescence property of the chelate was studied under the experimental conditions (pH 8.4 in H 3BO 3 KCl NaOH buffer, λ EX =309 nm, λ EM =374 nm). The fluorescence intensity is a linear function of concentration in the range of 5.0×10 -6 to 4.2×10 -4 mol/L for terbium. The relative standard deviation is less than ±2.0%. When tolerable amount of other metal ions were added to the solution of terbium chelate, the fluorescence intensity can be determined without interference. These results suggest that aromatic armed polyazamacrocycle can be used for the terbium determination.
文摘Glycine can react with acetylacetone and formaldehyde in HAc-NaAc buffer to give a product which can emit strong fluorescence.A Fluorometric determination of glycine in beverage was developed in the present work.The linear range was 0.1-200μg·mL-1.Experimental conditions such as pH of the solution,reaction temperature and reaction time were optimized.Effect of coexist compound was also discussed.The method can be applied to the determination of glycine in beverages.The recovery of the method is 91.8-107.5%.
基金supported by National Natural Science Foundation of China(Nos.21971223 and 21772178).
文摘Tetra(amino)azacalix[4]arene skeleton was functionalized at the bridging NH sites using various aromatic aldehydes via formation of imidazobenzimidazole fused heterocycles.X-ray single crystal analysis revealed distorted 1,3-alternate conformations for the resulting macrocycles.Anthracenyl and pyrenyl modified imidazobenzimidazole fused aza-calix[4]arenes existed as dimers in the solid state,associated mainly through-stacking interactions between the planar polycyclic fluorophores.The tetrapyrenyl modified product was further used as a Zn^(2+)-selective sensor,which showed naked-eye detected color change and enhanced excimer emission.The stoichiometry between the sensor and Zn2+was determined to be 1:1 and the association constant was 1.1×10^(5)L/mol.The sensing process was highly selective and showed strong anti-interference with presence of other cations.The UV-vis spectral changes in the sensing process were completely reversible by alternate addition of Zn^(2+) and F^(-),showing an efficient“on-off-on”result.
文摘Studies were performed to determine the extent of nuclear DNA degradation induced by iron, iron-ascorbate, or iron-bleomycin under aerobic conditions in a model system using isolated rat liver nuclei. The effects of five antioxidants (catalase, superoxide dismutase, dimethyl sulfoxide, glutathione and diallyl sulfide) on this oxidative nuclear damage were also investigated. At the 0.05 level for statistical significance, iron induced concentration-dependent DNA degradation, and this effect was enhanced by ascorbate and bleomycin. The antioxidants catalase, dimethyl sulfoxide, and diallyl sulfide significantly reduced the iron-ascorbate-induced DNA damage, whereas superoxide dismutase and dimethyl sulfoxide significantly reduced iron-bleomycin-induced damage. Glutathione significantly increased the iron-bleomycin-induced DNA damage. These results suggest that the reactive oxygen species generated by iron, iron-ascorbate, and iron-bleomycin are responsible for the DNA strand breaks in isolated rat liver nuclei.
文摘Anew opticalfiberfluorometricthermometerbased onthetemperature dependence ofthefluorescencelifetime of phosphoris described. The phase-locked detection (PLD) system is used to measure fluorescencelifetime. The characteristics ofthermometerare discussed and the experimentresults are given.
