Adsorptive voltammetric behavior of resveratrol at a silver electrode was investigated. And based on this, a linear scan voltammetry for determination of resveratrol had been found. The adsorption corresponded to the ...Adsorptive voltammetric behavior of resveratrol at a silver electrode was investigated. And based on this, a linear scan voltammetry for determination of resveratrol had been found. The adsorption corresponded to the Langmuir type isotherm curve, and the free energy of adsorption was caculated to be -46.21 kJ/mol at 298 K. The electrochemical parameters such as charge transfer coefficient α and standard electron transfer rate constant ks were estimated. In 0.2 mol/L KNO3+1.2×10 -4 mol/L KCl solution, resveratrol can give a sensitive anode peak at potential about 0.29 V（vs. SCE）. The linear range between the peak current and the concentration of resveratrol is 2.0×10 -9 to 1.0×10 -8 mol/L and 1.0×10 -8 to 9.0×10 -8 mol/L, respectively. The detection limit is 4.0×10 -10 mol/L. The method had been applied to the determination of resveratrol in wine.展开更多
Alizarin red S(ARS) causes a sharp incision in 0.1 mol/L KBr. In the presence of Zn 2+ , the incision depth of ARS decreased and a new incision of Zn-ARS coordination compound appeared. A second order differential sim...Alizarin red S(ARS) causes a sharp incision in 0.1 mol/L KBr. In the presence of Zn 2+ , the incision depth of ARS decreased and a new incision of Zn-ARS coordination compound appeared. A second order differential simple oscillographic voltammetric method for determination of Zn 2+ was developed. The method is applied to the determination of zinc gluconate in tablet. The linear range of Zn 2+ was 2.0×10 -7 ～8.6×10 -6 mol/L,detection limit 1×10 -7 mol/L, and RSD for determinations of 4.2×10 -6 mol/L Zn 2+ ( n=7 ) was 2.4%.展开更多
A new method of oscillographic chronopotentiometry at silver disk electrode for the determination was initially investigated and established. By using it, we determined a series of ions. The detection limits were decr...A new method of oscillographic chronopotentiometry at silver disk electrode for the determination was initially investigated and established. By using it, we determined a series of ions. The detection limits were decreased two or three orders of magnitude of that for the oscillographic chronopotentiometry at mercury electrode. This method was characterized by fine sensitivity, stable oscillogram and was not used for mercury. The research on mechanism of this method showed that these achievements were caused by the characteristics of silver electrooxidation and electroreduction and the A.C. oscillographic chronopotentiometry(ACOC).展开更多
文摘Adsorptive voltammetric behavior of resveratrol at a silver electrode was investigated. And based on this, a linear scan voltammetry for determination of resveratrol had been found. The adsorption corresponded to the Langmuir type isotherm curve, and the free energy of adsorption was caculated to be -46.21 kJ/mol at 298 K. The electrochemical parameters such as charge transfer coefficient α and standard electron transfer rate constant ks were estimated. In 0.2 mol/L KNO3+1.2×10 -4 mol/L KCl solution, resveratrol can give a sensitive anode peak at potential about 0.29 V（vs. SCE）. The linear range between the peak current and the concentration of resveratrol is 2.0×10 -9 to 1.0×10 -8 mol/L and 1.0×10 -8 to 9.0×10 -8 mol/L, respectively. The detection limit is 4.0×10 -10 mol/L. The method had been applied to the determination of resveratrol in wine.
文摘Alizarin red S(ARS) causes a sharp incision in 0.1 mol/L KBr. In the presence of Zn 2+ , the incision depth of ARS decreased and a new incision of Zn-ARS coordination compound appeared. A second order differential simple oscillographic voltammetric method for determination of Zn 2+ was developed. The method is applied to the determination of zinc gluconate in tablet. The linear range of Zn 2+ was 2.0×10 -7 ～8.6×10 -6 mol/L,detection limit 1×10 -7 mol/L, and RSD for determinations of 4.2×10 -6 mol/L Zn 2+ ( n=7 ) was 2.4%.
文摘A new method of oscillographic chronopotentiometry at silver disk electrode for the determination was initially investigated and established. By using it, we determined a series of ions. The detection limits were decreased two or three orders of magnitude of that for the oscillographic chronopotentiometry at mercury electrode. This method was characterized by fine sensitivity, stable oscillogram and was not used for mercury. The research on mechanism of this method showed that these achievements were caused by the characteristics of silver electrooxidation and electroreduction and the A.C. oscillographic chronopotentiometry(ACOC).
