Molybdenum（ Ⅵ ） is a biologically essential trace element and its role in an extremely wide variety of systems has been reported. Most common methods often fail to determine trace Mo （ Ⅵ ） in the analysis of mol...Molybdenum（ Ⅵ ） is a biologically essential trace element and its role in an extremely wide variety of systems has been reported. Most common methods often fail to determine trace Mo （ Ⅵ ） in the analysis of molybdenum-containing samples, due to limitations such as inadequate detection limits and matrix interference, which make the direct determinations impossible. To solve this problem, various approaches are employed to concentrate and separate Mo（ Ⅵ ） to detectable levels. Concentration and separation methods play a main role in the analysis of trace Mo（Ⅵ）. Therefore, many separation and preconcentration procedures have been developed for the determination of Mo （ Ⅵ ）.展开更多
Cyclic oligomers of phenolphthalein polyarylene ether sulfone(ketone) were prepared through cyclo-depolymerisation of corresponding polymers using CsF as the catalyst in dipolar aprotic solvent DMAc and DMF, and a fam...Cyclic oligomers of phenolphthalein polyarylene ether sulfone(ketone) were prepared through cyclo-depolymerisation of corresponding polymers using CsF as the catalyst in dipolar aprotic solvent DMAc and DMF, and a family of macrocycles containing from dimer up to at least heptamer were confirmed by GPC, HPLC and MALDI-TOF-MS. The yields of cyclics get as high as 86.3% and 87.9% respectively.展开更多
A novel method was developed for enrichment and separation of trace mercury using phenolphthalein modified by ethyl violet （EV）. The effects of different parameters, such as stirring time, various metal ions and sal...A novel method was developed for enrichment and separation of trace mercury using phenolphthalein modified by ethyl violet （EV）. The effects of different parameters, such as stirring time, various metal ions and salts, and the amounts of phenolphthalein, NH4SCN, and EV on the extraction rate of mercury were studied, to select the experimental conditions. Under optimum conditions, mercury can be adsorbed on the surface of microcrystalline phenolphthalein by the intermolecular acdon strength. The possible reaction mechanism for the enrichment of mercury was discussed in detail. Hg（Ⅱ） could be completely separated from Fe（Ⅱ）, Co（Ⅱ）, Ni（Ⅱ）, Mn（Ⅱ）, Cd（Ⅱ）, Cr（Ⅲ）, and Al（Ⅲ） in the solution. The proposed method has been successfully applied to the determination of trace mercury in industrial wastewater with the recoveries above 99%. The relative standard deviation for five replicate determinations of 0.04 μg·mL^-1 of Hg（Ⅱ） was found to be 1.4%, 1.1%, and 1.2%, respectively. The analytical results were very satisfactory.展开更多
A novel polyetheretherketone (PEK-C) prepared from phenolphthalein has been synthesized. In order to improve some of its properties for application in high performance membrane, the PEK-C has been sulfonated with conc...A novel polyetheretherketone (PEK-C) prepared from phenolphthalein has been synthesized. In order to improve some of its properties for application in high performance membrane, the PEK-C has been sulfonated with concentrated sulfuric acid. Degree of sulfonation can be regulated by controlling the temmperature and time of sulfonation. The characterization of the sulfonated PEK-C in sodium salt form has been made by IR, ~1H NMR and ^(13)C NMR etc. It is shown that the sulfonation appears to take place exclusively in the ortho position to phenolic ether of phenolphthalein unit. The result is in agreement with theoretical deduction. Some properties of the sulfonated PEK-C, such as solubility, transition temperature, thermal degradation and hydrophilicity have also been discussed.展开更多
A new method of using phenolphthalein loaded with 1-(2-pyridylazo)-2-naphthol (PAN) as solid phase extractant to separate and enrich trace copper in diverse water samples has been developed. The ef- fects of different...A new method of using phenolphthalein loaded with 1-(2-pyridylazo)-2-naphthol (PAN) as solid phase extractant to separate and enrich trace copper in diverse water samples has been developed. The ef- fects of different parameters, such as the amounts of PAN and phenolphthalein, stirring time, various salts and metal ions on the enrichment yield of Cu(II) have been investigated to select the experimental conditions. Under the optimum conditions, Cu(II) can be totally adsorbed on the surface of microcrys- talline phenolphthalein. By controlling appropriate acidity (pH=1.0), Cu(II) is completely separated from Cd(II), Pb(II), Mn(II), Co(II), Fe(III), Ni(II), Al(III), Zn(II) and Hg(II) in the solution. The possible reaction mechanism of the enrichment of copper is discussed in detail in this paper. The detection limit of this proposed method is found to be 0.03 μg·L-1 with the enrichment factor of 200. The recovery is in a range of 96.8%―105%. The standard deviation is less than 2.5%. The proposed method has been successfully applied to the determination of trace copper in different water samples with satisfactory results.展开更多
Acid-Base Indicator, Turmeric Rhizome (Curcuma longa) was extracted from the root of a turmeric plant. The turmeric was peeled, washed and dried in an oven at 60°C. It was ground into powder and soaked in hot ...Acid-Base Indicator, Turmeric Rhizome (Curcuma longa) was extracted from the root of a turmeric plant. The turmeric was peeled, washed and dried in an oven at 60°C. It was ground into powder and soaked in hot and cold ethanol for the extraction. The extract was filtered and part of it was concentrated to yield a reasonable quantity of turmeric indicator. On standardization of acid with a base, 0.05 M base respectively of Sodium hydroxide (NaOH), sodium carbonate (Na<sub>2</sub>CO<sub>3</sub>) and Disodium borate (B<sub>4</sub>Na<sub>2</sub>O<sub>7</sub>) were used. Hot and cold extracts of turmeric were used as indicators and were compared with methyl orange and phenolphthalein. On the preliminary test carried out, hot and cold turmeric indicator showed yellow colour in acid medium and orange colour in the base. Methyl orange showed red colour in acid but yellow in the base, phenolphthalein was colourless in acid but pink in the base. During titration there were colour changes at the end points in the entire test carried out. The average volumes at ends points were calculated, the molar concentrations and mass concentrations of the acids used were also determined. The results showed that there was no difference between the natural indicators used and the existing synthetic indicators which are toxic to our environment.展开更多
基金Supported by the Natural Science Foundation of Henan Province(No.0511020500).
文摘Molybdenum（ Ⅵ ） is a biologically essential trace element and its role in an extremely wide variety of systems has been reported. Most common methods often fail to determine trace Mo （ Ⅵ ） in the analysis of molybdenum-containing samples, due to limitations such as inadequate detection limits and matrix interference, which make the direct determinations impossible. To solve this problem, various approaches are employed to concentrate and separate Mo（ Ⅵ ） to detectable levels. Concentration and separation methods play a main role in the analysis of trace Mo（Ⅵ）. Therefore, many separation and preconcentration procedures have been developed for the determination of Mo （ Ⅵ ）.
文摘Cyclic oligomers of phenolphthalein polyarylene ether sulfone(ketone) were prepared through cyclo-depolymerisation of corresponding polymers using CsF as the catalyst in dipolar aprotic solvent DMAc and DMF, and a family of macrocycles containing from dimer up to at least heptamer were confirmed by GPC, HPLC and MALDI-TOF-MS. The yields of cyclics get as high as 86.3% and 87.9% respectively.
文摘A novel method was developed for enrichment and separation of trace mercury using phenolphthalein modified by ethyl violet （EV）. The effects of different parameters, such as stirring time, various metal ions and salts, and the amounts of phenolphthalein, NH4SCN, and EV on the extraction rate of mercury were studied, to select the experimental conditions. Under optimum conditions, mercury can be adsorbed on the surface of microcrystalline phenolphthalein by the intermolecular acdon strength. The possible reaction mechanism for the enrichment of mercury was discussed in detail. Hg（Ⅱ） could be completely separated from Fe（Ⅱ）, Co（Ⅱ）, Ni（Ⅱ）, Mn（Ⅱ）, Cd（Ⅱ）, Cr（Ⅲ）, and Al（Ⅲ） in the solution. The proposed method has been successfully applied to the determination of trace mercury in industrial wastewater with the recoveries above 99%. The relative standard deviation for five replicate determinations of 0.04 μg·mL^-1 of Hg（Ⅱ） was found to be 1.4%, 1.1%, and 1.2%, respectively. The analytical results were very satisfactory.
文摘A novel polyetheretherketone (PEK-C) prepared from phenolphthalein has been synthesized. In order to improve some of its properties for application in high performance membrane, the PEK-C has been sulfonated with concentrated sulfuric acid. Degree of sulfonation can be regulated by controlling the temmperature and time of sulfonation. The characterization of the sulfonated PEK-C in sodium salt form has been made by IR, ~1H NMR and ^(13)C NMR etc. It is shown that the sulfonation appears to take place exclusively in the ortho position to phenolic ether of phenolphthalein unit. The result is in agreement with theoretical deduction. Some properties of the sulfonated PEK-C, such as solubility, transition temperature, thermal degradation and hydrophilicity have also been discussed.
基金Supported by the State Key Development Program for Basic Research of China （2008CB617502）, the National Natural Science Foundation of China （20606025）, and Program for Changjiang Scholars and Innovative Research Team in University of China （IRT0641）.
基金Supported by the Natural Science Foundation of Henan Province (Grant No. 0511020500) Innovation Project Foundation of University in Henan Province (Grant No. [2001]513)
文摘A new method of using phenolphthalein loaded with 1-(2-pyridylazo)-2-naphthol (PAN) as solid phase extractant to separate and enrich trace copper in diverse water samples has been developed. The ef- fects of different parameters, such as the amounts of PAN and phenolphthalein, stirring time, various salts and metal ions on the enrichment yield of Cu(II) have been investigated to select the experimental conditions. Under the optimum conditions, Cu(II) can be totally adsorbed on the surface of microcrys- talline phenolphthalein. By controlling appropriate acidity (pH=1.0), Cu(II) is completely separated from Cd(II), Pb(II), Mn(II), Co(II), Fe(III), Ni(II), Al(III), Zn(II) and Hg(II) in the solution. The possible reaction mechanism of the enrichment of copper is discussed in detail in this paper. The detection limit of this proposed method is found to be 0.03 μg·L-1 with the enrichment factor of 200. The recovery is in a range of 96.8%―105%. The standard deviation is less than 2.5%. The proposed method has been successfully applied to the determination of trace copper in different water samples with satisfactory results.
文摘Acid-Base Indicator, Turmeric Rhizome (Curcuma longa) was extracted from the root of a turmeric plant. The turmeric was peeled, washed and dried in an oven at 60°C. It was ground into powder and soaked in hot and cold ethanol for the extraction. The extract was filtered and part of it was concentrated to yield a reasonable quantity of turmeric indicator. On standardization of acid with a base, 0.05 M base respectively of Sodium hydroxide (NaOH), sodium carbonate (Na<sub>2</sub>CO<sub>3</sub>) and Disodium borate (B<sub>4</sub>Na<sub>2</sub>O<sub>7</sub>) were used. Hot and cold extracts of turmeric were used as indicators and were compared with methyl orange and phenolphthalein. On the preliminary test carried out, hot and cold turmeric indicator showed yellow colour in acid medium and orange colour in the base. Methyl orange showed red colour in acid but yellow in the base, phenolphthalein was colourless in acid but pink in the base. During titration there were colour changes at the end points in the entire test carried out. The average volumes at ends points were calculated, the molar concentrations and mass concentrations of the acids used were also determined. The results showed that there was no difference between the natural indicators used and the existing synthetic indicators which are toxic to our environment.
