Vitamin B12 is a type of vitamin also known by the name cobalamin. B12 is involved in many metabolism activities, including DNA synthesis, nervous system, red blood formation and immune system. Therefore, we chose the...Vitamin B12 is a type of vitamin also known by the name cobalamin. B12 is involved in many metabolism activities, including DNA synthesis, nervous system, red blood formation and immune system. Therefore, we chose the Differential Pulse Polarography (DPP) method is that has a high sensitivity for the determination of vitamin B12. This determination was possible with cobalt present in vitamin B12 structure. Since Co(III) is formed from the oxidation of the vitamin, its polarographic behavior had to be determined in various electrolytes such as acetate, borate, phosphate and ammonia. The polarograms of Co(III) were taken in these electrolytes in which 1.0 M NH3/ (pH = 9.8) and 1.0 M AcOH/AcO- (pH = 4.0) were found as the most suitable electrolytes. This method was successfully applied vitamin of B12 determination in a 1 mL ampoule with high precision. The LOD was found as 3.7 × 10-7 for instead of (S/N = 3). Besides Co(III), interference effects of Zn(II), Ni(II), Cr(III), Fe(III), Cu(II), Cd(II) and Se(IV) were also studied. It was found that only Zn(II) peak had an overlap Co(III) peak in ammonium buffer. This problem could be solved by working in 1.0 M AcOH/AcO- (pH = 4.0) buffer. B12, which is 1000 μg in 1 mL vitamin ampoule, was found for 4 measurements as 999 ± 15 μg as a result of 95% confidence interval.展开更多
The formulas of current of first and second derivative of differential pulse polarography (DPP) which has been deduced in this paper indicate that derivative may be enhance the sensitivity of DPP. By the analogy/data ...The formulas of current of first and second derivative of differential pulse polarography (DPP) which has been deduced in this paper indicate that derivative may be enhance the sensitivity of DPP. By the analogy/data transformation, smoothing, and numerical differentiation,we can obtain the derivative current of DPP.展开更多
The determination of trace element Pb in electrolyte MnSO_4H_2SO_4 was studied with differential pulse po-larography. The trace Pb was originated from new type Pb-Ag-Ca alloy anode being used in preduction processof e...The determination of trace element Pb in electrolyte MnSO_4H_2SO_4 was studied with differential pulse po-larography. The trace Pb was originated from new type Pb-Ag-Ca alloy anode being used in preduction processof electrolytic MnO_2 (EMD). The KCl was added as background of electrolyte. The differential pulse polarco-gram obtained for Pb(Ⅱ) is well in peak contour and is easy to determination. The peak potential is -0. 44 V(vs Ag-AgCl potential , experimental valuel). The Pb content may be determined by standard addition methodwhich is simple , reliable and fast. This study presents some foundamental data for Pb-Ag-Ca anode (abbreviated to PAC anede). The consuming rate for PAC anode is evaluated as 4. 82% annually.展开更多
The second derivative differential pulse polarography was developed for the quantitative determination of active principles in medicinal herbs (baicalin in Scutellaria baicalensis Georgi, indigo in Baphicacanthus cusi...The second derivative differential pulse polarography was developed for the quantitative determination of active principles in medicinal herbs (baicalin in Scutellaria baicalensis Georgi, indigo in Baphicacanthus cusia (Nees) Bremek, paeonol in Paeonia suffruticosa Andr and piperine in Piper longum L ) The C O group in baicalin, indigo, paeonol and piperine could be reduced to CH OH in acidic solution at the dropping mercury electrode, and showed very good second derivative differential pulse polarographic peak at 1 550V, 1 300V, 1 630V and 0 860V (vs Ag/AgCl) respectively The linear relationship between concentration of baicalin, indigo, paeonol, piperine and peak height was obtained in the concentration range of 4 5×10 5 ～ 2 7×10 4 mol·L 1 , 3 8×10 5 ～ 4 2×10 4 mol·L 1 , 1 0～6 0×10 4 mol·L 1 and 7 0×10 5 ～2 5×10 4 mol·L 1 and the determination limits were 9 0×10 8 mol·L 1 , 8 4×10 9 mol·L 1 , 9 2×10 9 mol·L 1 and 8 7×10 9 mol·L 1 respectively This method is simple, rapid and sensitive, and the results are accurate展开更多
The determination of trace rhenium(Ⅶ)by differential pulse polarography in the system of H_2SO_4-(NH_2OH)_2·H_2SO_4-TeO_4^(2-) is markedly improved by the addition of Nitron,which is adsorbed on the surface of m...The determination of trace rhenium(Ⅶ)by differential pulse polarography in the system of H_2SO_4-(NH_2OH)_2·H_2SO_4-TeO_4^(2-) is markedly improved by the addition of Nitron,which is adsorbed on the surface of mercury electrode.The limit of detection is down to 2×10^(-10) M.The adsorptive peak potential is -0.80V(vs.SCE).In the ranges of 5×10^(-10)-10^(-8),1×10^(-8)-10^(-7) and 1× 10^(-7)-10^(-6)M,there are good linear relationships between the peak current increment and the concentration,of which the relative standard deviations are 9.5,6.6,1.8% respectively with the correlation coefficients of linear regression of 0.995—0.999.The results relating to this polarographic wave show that it is an adsorption-catalytic wave.The mechanism of the electrode reaction is dis- cussed.展开更多
基金the Gazi University research fund for the financial support of this research.
文摘Vitamin B12 is a type of vitamin also known by the name cobalamin. B12 is involved in many metabolism activities, including DNA synthesis, nervous system, red blood formation and immune system. Therefore, we chose the Differential Pulse Polarography (DPP) method is that has a high sensitivity for the determination of vitamin B12. This determination was possible with cobalt present in vitamin B12 structure. Since Co(III) is formed from the oxidation of the vitamin, its polarographic behavior had to be determined in various electrolytes such as acetate, borate, phosphate and ammonia. The polarograms of Co(III) were taken in these electrolytes in which 1.0 M NH3/ (pH = 9.8) and 1.0 M AcOH/AcO- (pH = 4.0) were found as the most suitable electrolytes. This method was successfully applied vitamin of B12 determination in a 1 mL ampoule with high precision. The LOD was found as 3.7 × 10-7 for instead of (S/N = 3). Besides Co(III), interference effects of Zn(II), Ni(II), Cr(III), Fe(III), Cu(II), Cd(II) and Se(IV) were also studied. It was found that only Zn(II) peak had an overlap Co(III) peak in ammonium buffer. This problem could be solved by working in 1.0 M AcOH/AcO- (pH = 4.0) buffer. B12, which is 1000 μg in 1 mL vitamin ampoule, was found for 4 measurements as 999 ± 15 μg as a result of 95% confidence interval.
文摘The formulas of current of first and second derivative of differential pulse polarography (DPP) which has been deduced in this paper indicate that derivative may be enhance the sensitivity of DPP. By the analogy/data transformation, smoothing, and numerical differentiation,we can obtain the derivative current of DPP.
文摘The determination of trace element Pb in electrolyte MnSO_4H_2SO_4 was studied with differential pulse po-larography. The trace Pb was originated from new type Pb-Ag-Ca alloy anode being used in preduction processof electrolytic MnO_2 (EMD). The KCl was added as background of electrolyte. The differential pulse polarco-gram obtained for Pb(Ⅱ) is well in peak contour and is easy to determination. The peak potential is -0. 44 V(vs Ag-AgCl potential , experimental valuel). The Pb content may be determined by standard addition methodwhich is simple , reliable and fast. This study presents some foundamental data for Pb-Ag-Ca anode (abbreviated to PAC anede). The consuming rate for PAC anode is evaluated as 4. 82% annually.
文摘The second derivative differential pulse polarography was developed for the quantitative determination of active principles in medicinal herbs (baicalin in Scutellaria baicalensis Georgi, indigo in Baphicacanthus cusia (Nees) Bremek, paeonol in Paeonia suffruticosa Andr and piperine in Piper longum L ) The C O group in baicalin, indigo, paeonol and piperine could be reduced to CH OH in acidic solution at the dropping mercury electrode, and showed very good second derivative differential pulse polarographic peak at 1 550V, 1 300V, 1 630V and 0 860V (vs Ag/AgCl) respectively The linear relationship between concentration of baicalin, indigo, paeonol, piperine and peak height was obtained in the concentration range of 4 5×10 5 ～ 2 7×10 4 mol·L 1 , 3 8×10 5 ～ 4 2×10 4 mol·L 1 , 1 0～6 0×10 4 mol·L 1 and 7 0×10 5 ～2 5×10 4 mol·L 1 and the determination limits were 9 0×10 8 mol·L 1 , 8 4×10 9 mol·L 1 , 9 2×10 9 mol·L 1 and 8 7×10 9 mol·L 1 respectively This method is simple, rapid and sensitive, and the results are accurate
文摘The determination of trace rhenium(Ⅶ)by differential pulse polarography in the system of H_2SO_4-(NH_2OH)_2·H_2SO_4-TeO_4^(2-) is markedly improved by the addition of Nitron,which is adsorbed on the surface of mercury electrode.The limit of detection is down to 2×10^(-10) M.The adsorptive peak potential is -0.80V(vs.SCE).In the ranges of 5×10^(-10)-10^(-8),1×10^(-8)-10^(-7) and 1× 10^(-7)-10^(-6)M,there are good linear relationships between the peak current increment and the concentration,of which the relative standard deviations are 9.5,6.6,1.8% respectively with the correlation coefficients of linear regression of 0.995—0.999.The results relating to this polarographic wave show that it is an adsorption-catalytic wave.The mechanism of the electrode reaction is dis- cussed.
