A simple and sensitive kinetic spectrophotometric method for the determination of trace amounts of titanium(IV),based upon the catalytic effect of Ti(IV) on the oxidation of acid chrome blue K (ACBK) by hydrogen perox...A simple and sensitive kinetic spectrophotometric method for the determination of trace amounts of titanium(IV),based upon the catalytic effect of Ti(IV) on the oxidation of acid chrome blue K (ACBK) by hydrogen peroxide in 0.002 mol/L sulfuric acid,is described. The reaction rate is monitored spectrophotometrically by measuring the decrease in absorbance of ACBK at 524 nm. The detection limit of the method is 1.01×10?9 g/mL,and the linear range is 0-0.048 mg/L. The influence of acidity,concentration of reactants,reaction time,reaction temperature and for-eign ions is also discussed. The optimum reaction conditions were established and some kinetic parameters determined. The apparent activation energy of the catalytic reaction is 5.32 kJ/mol. The relative standard deviation for the determi-nation of titanium(IV) at the concentration of 0.048 mg/L is calculated to be 1.31% (n = 11). In combination with sol-vent extraction separation,the method has been successfully applied to the determination of trace titanium(IV) in human hair,plant matter,tea and rock samples. The results are in good agreement with the certified values with the relative standard deviations (RSD) of 1.4%-3.5%.展开更多
Biosensor sensitive to hydrogen peroxide was made via methylene blue in Nafion gel as an electron transfer mediator. Cyclic voltommetry and chronoamperometry were for the first time used to illustrate the suitability ...Biosensor sensitive to hydrogen peroxide was made via methylene blue in Nafion gel as an electron transfer mediator. Cyclic voltommetry and chronoamperometry were for the first time used to illustrate the suitability of electrical communication between immobilized horseradish peroxidase and a glassy carbon electrode via methylene blue incorporated into a (Nafion) perfluorosulfonic acid cation exchange polymer film. The methylene blue mediator was strongly reatined inside Nafion film through hydrophobic interactions. Effects of applied potential, ionic strength, temperature and pH on the biosensor were investigated. The biosensor possessed a variety of advantages including high sensitivity, long term stability and rapid response to hydrogen peroxide with a detection limit of 0.1 μmol/L. The high sensitivity of the biosensor was due to the high efficiency of electron transfer between immobilized horseradish peroxidase and the electrode via methylene blue.展开更多
This research investigates the efficacy of activated Gmelina Wood Sawdust (GWS) as an adsorbent for the removal of methylene blue (MB) dye from aqueous solutions, in comparison with raw GWS. The study employs laborato...This research investigates the efficacy of activated Gmelina Wood Sawdust (GWS) as an adsorbent for the removal of methylene blue (MB) dye from aqueous solutions, in comparison with raw GWS. The study employs laboratory experiments to assess the percentage of dye removal across various temperature and pH conditions. The adsorption process is scrutinized under different parameters, encompassing contact time, initial dye concentration, adsorbent dosage, temperature, and pH. Results demonstrate that activated GWS surpasses its raw counterpart, showcasing superior MB dye removal percentages. Extended contact times increased initial dye concentrations, and higher adsorbent dosages contribute positively to removal efficiency, while temperature exhibits an inverse relationship with dye removal. Optimal adsorption occurs at a pH of 7.0, aligning with the adsorbent’s zero-point charge (pHzpc), underscoring the role of surface charge in the adsorption process. This study underscores the potential of activated GWS as an economical and promising adsorbent material for addressing pollutants. Furthermore, the utilization of activated carbon derived from abundant agricultural waste underscores an environmentally conscious approach to adsorption applications. The ability to tailor the size and properties of activated carbon particles opens avenues for optimizing adsorption capabilities, thereby presenting opportunities for enhanced water treatment solutions.展开更多
In this paper we discussed the behavior of a hydrogen atom in moving and found there is a speed threshold for hydrogen atom. As long as the speed of hydrogen reaches or beyond its speed threshold, the proton and elect...In this paper we discussed the behavior of a hydrogen atom in moving and found there is a speed threshold for hydrogen atom. As long as the speed of hydrogen reaches or beyond its speed threshold, the proton and electron in hydrogen atom will fly apart. We also discussed the effect of the movement of hydrogen atom on its absorption spectrum which is important in spectrum analysis.展开更多
Objective: The purpose of this study was to develop a novel colorimetric system for direct detection of hydrogen sulfide on the tongue dorsum from subjects with complaints of halitosis. Method: An assay system compris...Objective: The purpose of this study was to develop a novel colorimetric system for direct detection of hydrogen sulfide on the tongue dorsum from subjects with complaints of halitosis. Method: An assay system comprised of a cotton swab impregnated with zinc sulfate, attached chromatography paper, stabilizing solution, and coloring reagents for the methylene blue technique was developed. Using this system we investigated on the visualization of the hydrogen sulfide on the solid phase and possibility for evaluating the origin of oral malodor on the tongue dorsum. Results: The assay system made possible visualization of a linear curve ranging from 5.3 ng to 85 ng of hydrogen sulfide, with low reagent consumption and miniaturization. However, the sensitivity was different for gaseous and fluid samples. The biofilm of the tongue dorsum from subjects with complaints of halitosis showed different shades of methylene blue depending on the concentration of hydrogen sulfide. A positive correlation was found between hydrogen sulfide on the tongue dorsum and the concentration of VSC hydrogen sulfide in mouth breath as measured using an Oral Chroma semiconductor gas sensor. Conclusion: The results of this study suggest that the novel assay system can be used as a visual warning sensor for halitosis by measuring hydrogen sulfide on the tongue dorsum.展开更多
Azo dye cationic blue X GRL, which is non biodegradable toxic organic compound, is decolorized and subsequently mineralized by UV/H 2O 2/N 2 or UV/H 2O 2/air (O 2) system. The effects of initial solution conce...Azo dye cationic blue X GRL, which is non biodegradable toxic organic compound, is decolorized and subsequently mineralized by UV/H 2O 2/N 2 or UV/H 2O 2/air (O 2) system. The effects of initial solution concentration, initial solution pH, and some ions produced during the degradation on the rate of decolorization of cationic blue X GRL were investigated. The photodegradation of cationic blue X GRL approximately follows first order kinetics. The regression curve of the natural logarithm of concentration verus reaction time becomes less linear with initial concentration increasing. Oxygen and appropriate OH\+· generator can accelerate reaction rate. The effect of reaction atmosphere, initial concentration, light intensity on the optimal dosage of H 2O 2 were studied. It was found that the optimal H 2O 2 dosage was determined by UV light intensity. These intermediates of cationic blue X GRL decolorization are biodegradable.展开更多
基金Project 0520002 supported by the Natural Science Foundation of Jiangxi Province
文摘A simple and sensitive kinetic spectrophotometric method for the determination of trace amounts of titanium(IV),based upon the catalytic effect of Ti(IV) on the oxidation of acid chrome blue K (ACBK) by hydrogen peroxide in 0.002 mol/L sulfuric acid,is described. The reaction rate is monitored spectrophotometrically by measuring the decrease in absorbance of ACBK at 524 nm. The detection limit of the method is 1.01×10?9 g/mL,and the linear range is 0-0.048 mg/L. The influence of acidity,concentration of reactants,reaction time,reaction temperature and for-eign ions is also discussed. The optimum reaction conditions were established and some kinetic parameters determined. The apparent activation energy of the catalytic reaction is 5.32 kJ/mol. The relative standard deviation for the determi-nation of titanium(IV) at the concentration of 0.048 mg/L is calculated to be 1.31% (n = 11). In combination with sol-vent extraction separation,the method has been successfully applied to the determination of trace titanium(IV) in human hair,plant matter,tea and rock samples. The results are in good agreement with the certified values with the relative standard deviations (RSD) of 1.4%-3.5%.
文摘Biosensor sensitive to hydrogen peroxide was made via methylene blue in Nafion gel as an electron transfer mediator. Cyclic voltommetry and chronoamperometry were for the first time used to illustrate the suitability of electrical communication between immobilized horseradish peroxidase and a glassy carbon electrode via methylene blue incorporated into a (Nafion) perfluorosulfonic acid cation exchange polymer film. The methylene blue mediator was strongly reatined inside Nafion film through hydrophobic interactions. Effects of applied potential, ionic strength, temperature and pH on the biosensor were investigated. The biosensor possessed a variety of advantages including high sensitivity, long term stability and rapid response to hydrogen peroxide with a detection limit of 0.1 μmol/L. The high sensitivity of the biosensor was due to the high efficiency of electron transfer between immobilized horseradish peroxidase and the electrode via methylene blue.
文摘This research investigates the efficacy of activated Gmelina Wood Sawdust (GWS) as an adsorbent for the removal of methylene blue (MB) dye from aqueous solutions, in comparison with raw GWS. The study employs laboratory experiments to assess the percentage of dye removal across various temperature and pH conditions. The adsorption process is scrutinized under different parameters, encompassing contact time, initial dye concentration, adsorbent dosage, temperature, and pH. Results demonstrate that activated GWS surpasses its raw counterpart, showcasing superior MB dye removal percentages. Extended contact times increased initial dye concentrations, and higher adsorbent dosages contribute positively to removal efficiency, while temperature exhibits an inverse relationship with dye removal. Optimal adsorption occurs at a pH of 7.0, aligning with the adsorbent’s zero-point charge (pHzpc), underscoring the role of surface charge in the adsorption process. This study underscores the potential of activated GWS as an economical and promising adsorbent material for addressing pollutants. Furthermore, the utilization of activated carbon derived from abundant agricultural waste underscores an environmentally conscious approach to adsorption applications. The ability to tailor the size and properties of activated carbon particles opens avenues for optimizing adsorption capabilities, thereby presenting opportunities for enhanced water treatment solutions.
文摘In this paper we discussed the behavior of a hydrogen atom in moving and found there is a speed threshold for hydrogen atom. As long as the speed of hydrogen reaches or beyond its speed threshold, the proton and electron in hydrogen atom will fly apart. We also discussed the effect of the movement of hydrogen atom on its absorption spectrum which is important in spectrum analysis.
文摘Objective: The purpose of this study was to develop a novel colorimetric system for direct detection of hydrogen sulfide on the tongue dorsum from subjects with complaints of halitosis. Method: An assay system comprised of a cotton swab impregnated with zinc sulfate, attached chromatography paper, stabilizing solution, and coloring reagents for the methylene blue technique was developed. Using this system we investigated on the visualization of the hydrogen sulfide on the solid phase and possibility for evaluating the origin of oral malodor on the tongue dorsum. Results: The assay system made possible visualization of a linear curve ranging from 5.3 ng to 85 ng of hydrogen sulfide, with low reagent consumption and miniaturization. However, the sensitivity was different for gaseous and fluid samples. The biofilm of the tongue dorsum from subjects with complaints of halitosis showed different shades of methylene blue depending on the concentration of hydrogen sulfide. A positive correlation was found between hydrogen sulfide on the tongue dorsum and the concentration of VSC hydrogen sulfide in mouth breath as measured using an Oral Chroma semiconductor gas sensor. Conclusion: The results of this study suggest that the novel assay system can be used as a visual warning sensor for halitosis by measuring hydrogen sulfide on the tongue dorsum.
文摘Azo dye cationic blue X GRL, which is non biodegradable toxic organic compound, is decolorized and subsequently mineralized by UV/H 2O 2/N 2 or UV/H 2O 2/air (O 2) system. The effects of initial solution concentration, initial solution pH, and some ions produced during the degradation on the rate of decolorization of cationic blue X GRL were investigated. The photodegradation of cationic blue X GRL approximately follows first order kinetics. The regression curve of the natural logarithm of concentration verus reaction time becomes less linear with initial concentration increasing. Oxygen and appropriate OH\+· generator can accelerate reaction rate. The effect of reaction atmosphere, initial concentration, light intensity on the optimal dosage of H 2O 2 were studied. It was found that the optimal H 2O 2 dosage was determined by UV light intensity. These intermediates of cationic blue X GRL decolorization are biodegradable.
