Cyclic voltammetric behavior of electrooxidation of Mn(Ⅱ) under ultrasound and without ultrasound were compared. With the ultrasound irradiation the reduction peak potential of Pb(Ⅳ)/ Pb(Ⅱ) was found shifted negati...Cyclic voltammetric behavior of electrooxidation of Mn(Ⅱ) under ultrasound and without ultrasound were compared. With the ultrasound irradiation the reduction peak potential of Pb(Ⅳ)/ Pb(Ⅱ) was found shifted negatively about 0.14 V, initial electrolytic potential reduced 0.2 V and reduction peak current increased. At the same conditions,the conversion of Mn(Ⅱ) was increased. The optimum conditions for electrooxidation were 0.3 mol/L solution of Mn(Ⅱ), 6 mol/L H 2SO 4, electrolysis potential 2.3 V and 44 W ultrasound.展开更多
Three complexes of Mn（Ⅱ）with L-amino acid[L-Isoleucine（L-Ile）,L-Methionine（L-Met）,L-Tryptophan（L-Trp）]were synthesized and characterized by elemental analysis,infrared spectra and gravithem metrical analyses....Three complexes of Mn（Ⅱ）with L-amino acid[L-Isoleucine（L-Ile）,L-Methionine（L-Met）,L-Tryptophan（L-Trp）]were synthesized and characterized by elemental analysis,infrared spectra and gravithem metrical analyses.The catalytic activity of the three complexes for disproportionation of O2-was determined by NBT method.The result shows that the complexes have a high SOD-like activity,and the KQ values of complexes 1,2 and 3 are 0.78×107mol-1·L·s-1,1.28×107mol-1,and 1.50×107mol-1L·s-1,respectively.展开更多
The electrochemical behavior of Mn (Ⅲ)/Mn(Ⅱ)ion-pair on platinum electrode in acid media were studied by cyclic voltammetry.It was demonstrated that the redox process of Mn(Ⅲ)/Mn(Ⅱ) pair was a simple pseudo-revers...The electrochemical behavior of Mn (Ⅲ)/Mn(Ⅱ)ion-pair on platinum electrode in acid media were studied by cyclic voltammetry.It was demonstrated that the redox process of Mn(Ⅲ)/Mn(Ⅱ) pair was a simple pseudo-reversible one-electron reaction between Mn(Ⅲ) and Mn(Ⅱ).The electrochemical kinetics of the redox reaction on static Pt electrode was a mass transfer controlled one.The calculated diffusion coefficient of Mn(Ⅱ) was 1.48×10 -6cm 2/s.展开更多
A new method of simultaneous determining Cu(Ⅱ), Zn(Ⅱ), Fe(Ⅱ), Mn(Ⅱ), Co(Ⅱ)and Ni(Ⅱ) with a single sweep polarography was developed. The experiment condition was studied and the results shou that the optimum base...A new method of simultaneous determining Cu(Ⅱ), Zn(Ⅱ), Fe(Ⅱ), Mn(Ⅱ), Co(Ⅱ)and Ni(Ⅱ) with a single sweep polarography was developed. The experiment condition was studied and the results shou that the optimum base solution is that the residue got from evaporating 25 mL mixed solution, 2.5 mL 1.0 mol/L ethylenediamine, 3.0 mL 1 .0 mol/L ammonia-ammonium chloride,5.0mL, 10 % sodium sulfite and 0.5 mL 0.5 % gelatin were mixed and diluted to 25 mL, with water.Under the condition of this base solution, the polarography wave shapes of the six cations are ideal and without overlap of the peaks. In this base solution, Cu(Ⅱ), Zn(Ⅱ), Fe(Ⅱ), Mn(Ⅱ). Co(Ⅱ) and Ni(Ⅱ)in synthetic samples were determined with relative errors 0.4-9.4 % and relative standard deviations 0.8%- 12.2%. Under this experiment condition, one fold of Pb(Ⅱ), Cr(Ⅵ) and Mo(Ⅵ ) do not interere with the determination for Cu(Ⅱ). This method has been used to the simultaneous determination of the amount of the six cations in the samples of soil and Beiqi Tea. The relative standard deviations were 0.1%-2.1 % and recoveries were 93.5%-99.0 %.展开更多
文摘Cyclic voltammetric behavior of electrooxidation of Mn(Ⅱ) under ultrasound and without ultrasound were compared. With the ultrasound irradiation the reduction peak potential of Pb(Ⅳ)/ Pb(Ⅱ) was found shifted negatively about 0.14 V, initial electrolytic potential reduced 0.2 V and reduction peak current increased. At the same conditions,the conversion of Mn(Ⅱ) was increased. The optimum conditions for electrooxidation were 0.3 mol/L solution of Mn(Ⅱ), 6 mol/L H 2SO 4, electrolysis potential 2.3 V and 44 W ultrasound.
文摘Three complexes of Mn（Ⅱ）with L-amino acid[L-Isoleucine（L-Ile）,L-Methionine（L-Met）,L-Tryptophan（L-Trp）]were synthesized and characterized by elemental analysis,infrared spectra and gravithem metrical analyses.The catalytic activity of the three complexes for disproportionation of O2-was determined by NBT method.The result shows that the complexes have a high SOD-like activity,and the KQ values of complexes 1,2 and 3 are 0.78×107mol-1·L·s-1,1.28×107mol-1,and 1.50×107mol-1L·s-1,respectively.
文摘The electrochemical behavior of Mn (Ⅲ)/Mn(Ⅱ)ion-pair on platinum electrode in acid media were studied by cyclic voltammetry.It was demonstrated that the redox process of Mn(Ⅲ)/Mn(Ⅱ) pair was a simple pseudo-reversible one-electron reaction between Mn(Ⅲ) and Mn(Ⅱ).The electrochemical kinetics of the redox reaction on static Pt electrode was a mass transfer controlled one.The calculated diffusion coefficient of Mn(Ⅱ) was 1.48×10 -6cm 2/s.
文摘A new method of simultaneous determining Cu(Ⅱ), Zn(Ⅱ), Fe(Ⅱ), Mn(Ⅱ), Co(Ⅱ)and Ni(Ⅱ) with a single sweep polarography was developed. The experiment condition was studied and the results shou that the optimum base solution is that the residue got from evaporating 25 mL mixed solution, 2.5 mL 1.0 mol/L ethylenediamine, 3.0 mL 1 .0 mol/L ammonia-ammonium chloride,5.0mL, 10 % sodium sulfite and 0.5 mL 0.5 % gelatin were mixed and diluted to 25 mL, with water.Under the condition of this base solution, the polarography wave shapes of the six cations are ideal and without overlap of the peaks. In this base solution, Cu(Ⅱ), Zn(Ⅱ), Fe(Ⅱ), Mn(Ⅱ). Co(Ⅱ) and Ni(Ⅱ)in synthetic samples were determined with relative errors 0.4-9.4 % and relative standard deviations 0.8%- 12.2%. Under this experiment condition, one fold of Pb(Ⅱ), Cr(Ⅵ) and Mo(Ⅵ ) do not interere with the determination for Cu(Ⅱ). This method has been used to the simultaneous determination of the amount of the six cations in the samples of soil and Beiqi Tea. The relative standard deviations were 0.1%-2.1 % and recoveries were 93.5%-99.0 %.
