Under the condition of 100 ℃ and hydrochloric acid as medium,the depigmentation reaction of potassium periodate oxidizing AzureⅡcan be greatly catalyzed by rhodium(III).A new catalytic kinetic analyzing method was e...Under the condition of 100 ℃ and hydrochloric acid as medium,the depigmentation reaction of potassium periodate oxidizing AzureⅡcan be greatly catalyzed by rhodium(III).A new catalytic kinetic analyzing method was established based on that.The optimal experimental condition of the reaction was discussed.The absorbency difference △A remained good linear relationship with the mass concentration of rhodium(III)in the range of 0.004-0.060 μg·mL-1,and the detection limit was 1.09×10-10 g·mL.The relative standard deviation RSD was 1.15%(n=13).The dynamic parameter was also determined and the reaction a first order reaction to rhodium(III) and the total reaction was pseudo first order reaction.The apparent rate constant was 1.09×10-3s-1,and the apparent activation energy was 76.07 kJ·mol-1.It was applied to the determination of rhodium(III) in sample molecular sieve and active carbon with the recovery rate between 103.6-105.2 % that met the request of trace analysis.展开更多
以硫酸亚铁铵、草酸为主要原料,双氧水为氧化剂合成三草酸合铁(Ⅲ)酸钾。采用响应面法优化三草酸合铁(Ⅲ)酸钾的制备工艺,用XRD、FT-IR、SEM对产物进行表征。结果表明,产物化学式为K[Fe(C_2O_4)_3]·3H_2O,形貌为微米块状颗粒。优...以硫酸亚铁铵、草酸为主要原料,双氧水为氧化剂合成三草酸合铁(Ⅲ)酸钾。采用响应面法优化三草酸合铁(Ⅲ)酸钾的制备工艺,用XRD、FT-IR、SEM对产物进行表征。结果表明,产物化学式为K[Fe(C_2O_4)_3]·3H_2O,形貌为微米块状颗粒。优化工艺条件:草酸亚铁制备中草酸用量为28.00 m L、反应时间为18.00 min;氧化配位反应中草酸钾用量为17.00 m L、H_2O_2用量为6.00 m L,清除H_2O_2时间为5.00 min;酸溶配位中草酸用量为11.00 m L,在该条件下重复实验,产品均为翠绿色晶体,产率均在89.89%~90.57%之间。展开更多
A highly sensitive and selective catalytic kinetic spectrophotometric method for the determination of Cu(Ⅱ) is proposed. It is based on the catalytic effect of Cu(Ⅱ) on the oxidation of glutathione(GSH) by potassium...A highly sensitive and selective catalytic kinetic spectrophotometric method for the determination of Cu(Ⅱ) is proposed. It is based on the catalytic effect of Cu(Ⅱ) on the oxidation of glutathione(GSH) by potassium hexacyanoferrate(Ⅲ) in acidic medium at 25.0℃. The reaction is monitored spectrophotometrically by measuring the decrease in absorbance of oxidant at 420 nm using the fix-time method. Under the optimum conditions, the proposed method allows the determination of Cu(Ⅱ) in a range of 0-35.0 ng m L^(-1) with good precision and accuracy and the limit of detection is down to 0.04 ng m L^(-1). The relative standard deviation(RSD) is 1.02%. The reaction orders with respect to each reagent are found to be 1, 1/2, and 1/2 for potassium hexacyanoferrate(Ⅲ), glutathione and Cu(Ⅱ) respectively. On the basis of these values, the rate equation is obtained and the possible mechanism is established. Moreover, few anions and cations can interfere with the determination of Cu(Ⅱ). The new proposed method can be successfully used to the determination of Cu(Ⅱ) in fresh water samples and seawater samples. It is found that the proposed method has fairly good selectivity, high sensitivity, good repeatability, simplicity and rapidity.展开更多
A kinetic study of the electron-transfer in the reaction of tribenzylchlorotin with potassium 12-tungsto cobalt （Ⅲ） ate ion, Ks[CoW12O40], abbreviated as Co（III）W, has been performed in different solvents. The st...A kinetic study of the electron-transfer in the reaction of tribenzylchlorotin with potassium 12-tungsto cobalt （Ⅲ） ate ion, Ks[CoW12O40], abbreviated as Co（III）W, has been performed in different solvents. The studies were carried out in methanol, ethanol, acetonitrile and acetic acid/water. The rate constants, reaction rates and activation parameters were calculated. Our findings show that the rate of disappearance of the Co（Ⅲ） is pseudo-first order. The kinetic data is strongly affected by used solvents. The maximum and minimum rate constants were achieved in the ethanol and acetic acid/water （70/30） as a solvent, respectively. In all of the used solvents, negative value of activation entropies was observed, but negative activation enthalpies are observed in methanol, ethanol and acetonitrile. The reaction rate is increased with increase of Co（Ⅲ） concentration. ？2009 Fatemeh E Bamoharram. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
文摘Under the condition of 100 ℃ and hydrochloric acid as medium,the depigmentation reaction of potassium periodate oxidizing AzureⅡcan be greatly catalyzed by rhodium(III).A new catalytic kinetic analyzing method was established based on that.The optimal experimental condition of the reaction was discussed.The absorbency difference △A remained good linear relationship with the mass concentration of rhodium(III)in the range of 0.004-0.060 μg·mL-1,and the detection limit was 1.09×10-10 g·mL.The relative standard deviation RSD was 1.15%(n=13).The dynamic parameter was also determined and the reaction a first order reaction to rhodium(III) and the total reaction was pseudo first order reaction.The apparent rate constant was 1.09×10-3s-1,and the apparent activation energy was 76.07 kJ·mol-1.It was applied to the determination of rhodium(III) in sample molecular sieve and active carbon with the recovery rate between 103.6-105.2 % that met the request of trace analysis.
文摘以硫酸亚铁铵、草酸为主要原料,双氧水为氧化剂合成三草酸合铁(Ⅲ)酸钾。采用响应面法优化三草酸合铁(Ⅲ)酸钾的制备工艺,用XRD、FT-IR、SEM对产物进行表征。结果表明,产物化学式为K[Fe(C_2O_4)_3]·3H_2O,形貌为微米块状颗粒。优化工艺条件:草酸亚铁制备中草酸用量为28.00 m L、反应时间为18.00 min;氧化配位反应中草酸钾用量为17.00 m L、H_2O_2用量为6.00 m L,清除H_2O_2时间为5.00 min;酸溶配位中草酸用量为11.00 m L,在该条件下重复实验,产品均为翠绿色晶体,产率均在89.89%~90.57%之间。
文摘A highly sensitive and selective catalytic kinetic spectrophotometric method for the determination of Cu(Ⅱ) is proposed. It is based on the catalytic effect of Cu(Ⅱ) on the oxidation of glutathione(GSH) by potassium hexacyanoferrate(Ⅲ) in acidic medium at 25.0℃. The reaction is monitored spectrophotometrically by measuring the decrease in absorbance of oxidant at 420 nm using the fix-time method. Under the optimum conditions, the proposed method allows the determination of Cu(Ⅱ) in a range of 0-35.0 ng m L^(-1) with good precision and accuracy and the limit of detection is down to 0.04 ng m L^(-1). The relative standard deviation(RSD) is 1.02%. The reaction orders with respect to each reagent are found to be 1, 1/2, and 1/2 for potassium hexacyanoferrate(Ⅲ), glutathione and Cu(Ⅱ) respectively. On the basis of these values, the rate equation is obtained and the possible mechanism is established. Moreover, few anions and cations can interfere with the determination of Cu(Ⅱ). The new proposed method can be successfully used to the determination of Cu(Ⅱ) in fresh water samples and seawater samples. It is found that the proposed method has fairly good selectivity, high sensitivity, good repeatability, simplicity and rapidity.
文摘A kinetic study of the electron-transfer in the reaction of tribenzylchlorotin with potassium 12-tungsto cobalt （Ⅲ） ate ion, Ks[CoW12O40], abbreviated as Co（III）W, has been performed in different solvents. The studies were carried out in methanol, ethanol, acetonitrile and acetic acid/water. The rate constants, reaction rates and activation parameters were calculated. Our findings show that the rate of disappearance of the Co（Ⅲ） is pseudo-first order. The kinetic data is strongly affected by used solvents. The maximum and minimum rate constants were achieved in the ethanol and acetic acid/water （70/30） as a solvent, respectively. In all of the used solvents, negative value of activation entropies was observed, but negative activation enthalpies are observed in methanol, ethanol and acetonitrile. The reaction rate is increased with increase of Co（Ⅲ） concentration. ？2009 Fatemeh E Bamoharram. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
