A simple and highly sensitive analysis by electrochemical voltammetry has been developed for diagnosis of the most destructive crop disease in Thailand known as sugarcane white leaf (SCWL). Determination of the corres...A simple and highly sensitive analysis by electrochemical voltammetry has been developed for diagnosis of the most destructive crop disease in Thailand known as sugarcane white leaf (SCWL). Determination of the corresponding DNA interaction has been obtained from the voltammetric signals of electroactive redox methylene blue (MB) by means of cyclic and differential pulse voltammetry. In this study, a chitosan-modified glassy carbon electrode (GCE) was created by self-assembly to produce electrostatic platform for effective immobilization of the DNA. Fabrication of SCWL-DNA hybridization detection system was performed by immobilizing the ssDNA probe as a specific sensor onto chitosan-modified GCE. Hybridization of complementary DNA from the real samples could then be detected by its respective MB signal. This fabricated DNA probe sensor was shown to be capable for discriminative identification among the DNAs from SCWL plants, mosaic virus infected sugarcane and healthy sugarcane plants. Relationship between the specific hybridization signal and DNA target concentration was also observed under optimal condition. The detection limit of 4.709 ng/μl with the regression coefficient (R2) of 0.998 and overall RSD of 2.44% were obtained by response curve fit analysis. The actual SCWL-ssDNA immobilization and hybridizing event were subsequently confirmed by an observation under atomic force microscope. Thus these experiments demonstrate the first successful and effective DNA based voltammetric electrochemical determination for a verification of the specific pathogenic infection within plants from the real epidemic field.展开更多
Adsorptive enhancements of several water-soluble polymers on copper(Ⅱ) were studied by adsorptive stripping voltammetry with a hanging mercury drop electrode. Increases in peak current of cu(Ⅱ) were observed in al...Adsorptive enhancements of several water-soluble polymers on copper(Ⅱ) were studied by adsorptive stripping voltammetry with a hanging mercury drop electrode. Increases in peak current of cu(Ⅱ) were observed in alkaline carbonate media. The enhancing power of poly(vinyl alcohol), starch and polyallylamine is 15, 4. 1, and 2.5 times, repectively展开更多
A new voltammetric enzyme immunoassay system was investigated based on p-nitrophenyl phosphate (PNPP) as the substrate for alkaline phosphatase (ALP). PNPP is enzymatically hydrolyzed and the product p-nitrophenol (P...A new voltammetric enzyme immunoassay system was investigated based on p-nitrophenyl phosphate (PNPP) as the substrate for alkaline phosphatase (ALP). PNPP is enzymatically hydrolyzed and the product p-nitrophenol (PNP) is detected by differential pulse voltammetry (DPV), which can be oxidized at +1.02 V (vs. Ag/AgCl) on bare glass carbon electrode (GCE). The conditions for enzymatic reaction and electrochemical detection were studied. According to this method, ALP can be detected with a detection limit of 2.8102 mU/L and a linear range of 4.0102 ~ 1.0106 mU/L.展开更多
The electrochemical oxidation behaviors of adrenaline(AD)and its Be(Ⅱ)complex have been studied by voltammetric method with a carbon paste working electrode.On the bases of calculation of the atomic net electronic ch...The electrochemical oxidation behaviors of adrenaline(AD)and its Be(Ⅱ)complex have been studied by voltammetric method with a carbon paste working electrode.On the bases of calculation of the atomic net electronic charges of AD molecule by INDO approximate method and results of comparative experiment with dopamine the possible coordination site of Be(Ⅱ)-AD complex is proposed.展开更多
In a supporting electrolyte containing 0.6mol/L H_2SO_4,a sensitivity derivative wave of 2-AES is formed by oscillopolarography.The peak potential is-1.01V(vs.SCE),The change of peak height with the concentration of 2...In a supporting electrolyte containing 0.6mol/L H_2SO_4,a sensitivity derivative wave of 2-AES is formed by oscillopolarography.The peak potential is-1.01V(vs.SCE),The change of peak height with the concentration of 2-AES is linear in the range from 3.0×10^(-7) to 8.0×10^(-6)mol/L.The detection limit is 1.0×10^(-7)mol/L.The electrode reaction mechanism is discussed.展开更多
The indirect voltammetric determination of trace sulfate (2.0×10^(-6)～4.0×10^(-5) mol/L ) with the adsorptive complex wave of lead(Ⅱ)-tetrakis (4-trimethylammonium phenyl) porphyrin (PbTTMAPP) is reported....The indirect voltammetric determination of trace sulfate (2.0×10^(-6)～4.0×10^(-5) mol/L ) with the adsorptive complex wave of lead(Ⅱ)-tetrakis (4-trimethylammonium phenyl) porphyrin (PbTTMAPP) is reported.This method has been used for the analysis of natural waters with satisfactory results.展开更多
The voltammetric behaviors of rare earth ions-amino acids were studied.The reduction potential of Eu^(3+) was shifted positively and the peak separation of the cathodic and anodic peaks in cyclic voltammogram de- crea...The voltammetric behaviors of rare earth ions-amino acids were studied.The reduction potential of Eu^(3+) was shifted positively and the peak separation of the cathodic and anodic peaks in cyclic voltammogram de- creased when a certain amino acid was added to Eu^(3+) solution.Experimental results showed that Eu^(3+) was re- duced by way of forming complexes with amino acids which were adsorbed on mercury electrode surface.When histidine and formaldehyde existed simultaneously in the solution containing Eu^(3+),a well-defined reversible catalytic prewave of Eu^(3+) was obtained.Meanwhile,the reduction current of formaldehyde increased greatly with the addition of histidine.The mechanism was studied.Several other rare earth ions and amino acids were also studied preliminarily.展开更多
Electrochemistry of nitrate reductases (NR) incorporated into 2-aminoethanethiol self-assembled on the gold electrode and polyacrylamide cast on the pyrolytic graphite electrode was examined. NR on chemical modified ...Electrochemistry of nitrate reductases (NR) incorporated into 2-aminoethanethiol self-assembled on the gold electrode and polyacrylamide cast on the pyrolytic graphite electrode was examined. NR on chemical modified electrode showed electrochemical cyclic voltammetric responses in phosphate buffers.展开更多
The voltammetric behavior of indigo carmine at mercury film electrode on a silver substrate (MFES) was studied in this paper. It was found that indigo carmine gave a sensitive reduction peak at a potential (Vp) of -0....The voltammetric behavior of indigo carmine at mercury film electrode on a silver substrate (MFES) was studied in this paper. It was found that indigo carmine gave a sensitive reduction peak at a potential (Vp) of -0.11 V at pH 4.0 in aqueous solution. The MFES gave good reproducibility and life time. The peak currents (ip) depended lipearly on the concentrations of indigo carmine free 0 to 100 ng/ml. The Vp and Ip of indigo carmine at MFES were independent of the concentrations of amaranth at pH 4.0, the Vp of amaranth was -0.24 V at this pH. The differences of Vp between both colorants enabled to distinguish indigo carmine free amaranth.展开更多
Electrochemical voltammetric method can;be used to monitor cell health state during its growth. Here we studied the effect of caffeic acid on leukemia cells U937 by the voltammetric behavior of the cells. The result s...Electrochemical voltammetric method can;be used to monitor cell health state during its growth. Here we studied the effect of caffeic acid on leukemia cells U937 by the voltammetric behavior of the cells. The result showed that this drug had a negative influence on cell health. which suggests that caffeic acid may be used in inhibition of tumor cells.展开更多
The voltammetric and polarographic behaviours of 14 rare earth elements were investigated in anhydrous acetone.The influence of residual oxygen on their waves was examined.At a concentration lower than 6× 10^(-4)...The voltammetric and polarographic behaviours of 14 rare earth elements were investigated in anhydrous acetone.The influence of residual oxygen on their waves was examined.At a concentration lower than 6× 10^(-4)mol/L,Eu^(3+),Yb^(3+)and Sm^(3+) produce two waves and other rare earth ions exhibit only one wave. When the concentration is greater than 8×10^(-4)mol/L,two waves could be observed on the reduction of Yb^(2+),Sm^(2+)and other RE^(3+)ions except for Eu^(3+).By adding 0.6% H_2O(or 1×10^(-4)mol/L NH_4ClO_4) one well-defined wave appears instead of two.The phenomenon is explained that a thin deposit film may be formed at electrode surface owing to the interaction of RE^(3+) with O_2^-,which is the reduction product of trace oxygen in aprotic solvent.In the presence of a proton donor such as H_2O or NH_4^+,oxygen reduces directly to H_2O_2 and eliminates the appearance of two waves.展开更多
The electroanalytical method of ferriheme was studied by linear sweep voltammetry in medium of 0.05 mol/L Tris+0.05 mol/L NH3?NH4Cl buffer at hang mercury drop electrodes (HMDE). Heme exhibits two pair reversible redo...The electroanalytical method of ferriheme was studied by linear sweep voltammetry in medium of 0.05 mol/L Tris+0.05 mol/L NH3?NH4Cl buffer at hang mercury drop electrodes (HMDE). Heme exhibits two pair reversible redox peaks and one irreversible peak. The cathodic peak potentials are?;0.236 V, ?0.422 V and ?1.408 V respectively. The first and the third peaks can be used for directly quantitative determination of heme concentrations. The peak currents are good linear relationship with heme concentration in ranges of 3×10?6–6×10?5 mol/L and 3×10?7–1.5×10?5 mol/L respectively.展开更多
A new method called spline convolution (SC) for resolving overlapped peaks was proposed in this paper. The differential pulse voltammetric overlapped peaks of mixtures of Pb(II) and Tl(I) were investigated by this me...A new method called spline convolution (SC) for resolving overlapped peaks was proposed in this paper. The differential pulse voltammetric overlapped peaks of mixtures of Pb(II) and Tl(I) were investigated by this method, and satisfactory results were obtained. The results show excellent correlation between peak areas of the processed signals and the concentrations.展开更多
The rate of voltammetric reduction of Eu(Ⅲ)in acetate solution was increased by the formation of a complex with ribose,lyxose or arabinose.If a ternary complex of Eu(Ⅲ)-D-ribose-L-phenylanaline formed on the surface...The rate of voltammetric reduction of Eu(Ⅲ)in acetate solution was increased by the formation of a complex with ribose,lyxose or arabinose.If a ternary complex of Eu(Ⅲ)-D-ribose-L-phenylanaline formed on the surface of mercury electrode,the redox process of Eu(Ⅲ)became more reversible than that of Eu(Ⅲ)-D-ribose in solution phase.展开更多
In the 0.3mol/L NH_4Cl supporting electrolyte,salicyl-fluorone exhibits a sensitive adsorptive wave by using linear scanning voltammetry with Ep_1=-0.70V and a diffusion wave with Ep_2=-0.68V(v8,SCE)at pH 2.5.On the s...In the 0.3mol/L NH_4Cl supporting electrolyte,salicyl-fluorone exhibits a sensitive adsorptive wave by using linear scanning voltammetry with Ep_1=-0.70V and a diffusion wave with Ep_2=-0.68V(v8,SCE)at pH 2.5.On the surface of HMDE, the adsorption of salieyl-fluorone obeys Frumkin adsorption isotherm.The adsorption coefficient(B),and attractive factor(v)and the amount of saturated adsorption(Γs)have been determined.展开更多
Adsorptive enhancements of several inorganic salts on copper(II) were studied by adsorptive stripping voltammetry with a hanging mercury drop electrode Increase in peak curren of cu(II) were observed in alkaline phosp...Adsorptive enhancements of several inorganic salts on copper(II) were studied by adsorptive stripping voltammetry with a hanging mercury drop electrode Increase in peak curren of cu(II) were observed in alkaline phosphate or media owing to adsorption Silicate can also enhance the peak current of Cu(II). The enhancing power phosphate,carbonate, and silicate is 33, 26, and 8.9 times, respectively.展开更多
The electrochemical behavior of N,N-diethyl-p-nitroso aniline was carried out using SWV （square wave voltammetric） at HMDE. A well defined reduction peak was observed at （-0.214） volt versus the reference electro...The electrochemical behavior of N,N-diethyl-p-nitroso aniline was carried out using SWV （square wave voltammetric） at HMDE. A well defined reduction peak was observed at （-0.214） volt versus the reference electrode （Ag/AgC1/sat. KCI）, calibration curve was constructed in phosphate buffer （pH = 7.0）, the relationship is linear within the concentration range 1.283 × 10.5 M - 3.66 × 10.5 M with the correlation （R = 0.9923）. The serial addition ofCPM （chlorpheniramine maleate） leads to the decrease in the reduction current peak （Ip）, quantitatively, the plot of Alp （Ip - Ip） where, Ip： Peak current of N, N-diethyl-p-nitroso aniline alone, lp： peak current of N,N-diethyl-p-nitroso aniline in the presence of CPM, versus concentration is linear within the concentration range 0.984 × 10-6 M - 9.756 × 10-6 M, the correlation coefficient was 0.9954. The method was successfully applied to determine CPM in different types of pharmaceutical formulations, and compared with standard method from British Pharmacopeia [1].展开更多
Cyclic voltammetry shows that DBPPH has a pair of cathodic and anodic peaks at Hg electrode.Epc=-1.49 V and Fpa=-1.43 V(vs.Ag/AgCl).The cathodic peak shows adsorptive characteristics.The adsorbed species is DBPPH neut...Cyclic voltammetry shows that DBPPH has a pair of cathodic and anodic peaks at Hg electrode.Epc=-1.49 V and Fpa=-1.43 V(vs.Ag/AgCl).The cathodic peak shows adsorptive characteristics.The adsorbed species is DBPPH neutral molecule. The method for measuring trace amount of DBPPH by adsorptive stripping voltammetry is established.展开更多
The electroanalytic method of ferriheme was investigated bylinear sweep voltammetry in medium of 0.05M Tris+0.05MNH3-NH4Cl buffer at hang mercury drop electrodes （HMDE）. Hemeexhibits two pair reversible redox peaks ...The electroanalytic method of ferriheme was investigated bylinear sweep voltammetry in medium of 0.05M Tris+0.05MNH3-NH4Cl buffer at hang mercury drop electrodes （HMDE）. Hemeexhibits two pair reversible redox peaks and one irreversible peak. Thecathodic peak potentials are -0.236V, -0.422V and -1.408V respectively. The firstand the third peaks can be used for directly quantitative determination of hemeconcentration. The peak currents are good linear relationship hemeconcentration in ranges of 3×10-6～ 6×10-5mol/L and 3×10-7～ 1.5×10-5mol/L respectively. A preliminary discussion on properties of the hemevoltammetric behavior has been suggested.展开更多
Tembotrione is herbicide which belongs to the triketone group of herbicides. It’s registered as a selective, post-emergence herbicide developed for the control of a broad spectrum broadleaf and grassy weeds in corn. ...Tembotrione is herbicide which belongs to the triketone group of herbicides. It’s registered as a selective, post-emergence herbicide developed for the control of a broad spectrum broadleaf and grassy weeds in corn. There is little information about tembotrione because of his short presence in the market. Due to its ever wider application, it is important to know the details of its chemical characteristics and redox processes, including biogeochemical transformation and migration after application to agricultural land, which could contribute to its efficient and safer application. In this paper we examined voltammetric behavior of tembotrione using Silver/Amalgam (Ag/Hg) electrode. For the investigation of electrochemical behavior we used the cyclic voltammetry technique, with conventional three-electrode cell and electrochemical workstation. During the experiment pH values of solution varieties while constant concentration of tembotrione was maintained. Cyclic voltammograms were recorded at pH values 6, 8, 10 and 12, at which tembotrione was electrochemically active. At this pH values two signals were observed. Optimum pH value, at which the current intensity was greatest, was 12. Obtained results provide relevant information on the electrochemical behavior of tembotrione, which can serve as a basis for the development of electrochemical techniques for the removal and degradation of this pesticide in the environment.展开更多
文摘A simple and highly sensitive analysis by electrochemical voltammetry has been developed for diagnosis of the most destructive crop disease in Thailand known as sugarcane white leaf (SCWL). Determination of the corresponding DNA interaction has been obtained from the voltammetric signals of electroactive redox methylene blue (MB) by means of cyclic and differential pulse voltammetry. In this study, a chitosan-modified glassy carbon electrode (GCE) was created by self-assembly to produce electrostatic platform for effective immobilization of the DNA. Fabrication of SCWL-DNA hybridization detection system was performed by immobilizing the ssDNA probe as a specific sensor onto chitosan-modified GCE. Hybridization of complementary DNA from the real samples could then be detected by its respective MB signal. This fabricated DNA probe sensor was shown to be capable for discriminative identification among the DNAs from SCWL plants, mosaic virus infected sugarcane and healthy sugarcane plants. Relationship between the specific hybridization signal and DNA target concentration was also observed under optimal condition. The detection limit of 4.709 ng/μl with the regression coefficient (R2) of 0.998 and overall RSD of 2.44% were obtained by response curve fit analysis. The actual SCWL-ssDNA immobilization and hybridizing event were subsequently confirmed by an observation under atomic force microscope. Thus these experiments demonstrate the first successful and effective DNA based voltammetric electrochemical determination for a verification of the specific pathogenic infection within plants from the real epidemic field.
文摘Adsorptive enhancements of several water-soluble polymers on copper(Ⅱ) were studied by adsorptive stripping voltammetry with a hanging mercury drop electrode. Increases in peak current of cu(Ⅱ) were observed in alkaline carbonate media. The enhancing power of poly(vinyl alcohol), starch and polyallylamine is 15, 4. 1, and 2.5 times, repectively
基金The work was supported by the National Natural Science Foundation of China(Grant No.20075013)the Natural Science Foundation of Shandong Province(Grant No.Y98B06025).
文摘A new voltammetric enzyme immunoassay system was investigated based on p-nitrophenyl phosphate (PNPP) as the substrate for alkaline phosphatase (ALP). PNPP is enzymatically hydrolyzed and the product p-nitrophenol (PNP) is detected by differential pulse voltammetry (DPV), which can be oxidized at +1.02 V (vs. Ag/AgCl) on bare glass carbon electrode (GCE). The conditions for enzymatic reaction and electrochemical detection were studied. According to this method, ALP can be detected with a detection limit of 2.8102 mU/L and a linear range of 4.0102 ~ 1.0106 mU/L.
基金The project has been supported by National Natural Science Foundation of China.
文摘The electrochemical oxidation behaviors of adrenaline(AD)and its Be(Ⅱ)complex have been studied by voltammetric method with a carbon paste working electrode.On the bases of calculation of the atomic net electronic charges of AD molecule by INDO approximate method and results of comparative experiment with dopamine the possible coordination site of Be(Ⅱ)-AD complex is proposed.
基金The project was Supported by The National Natural Science Foundation of China
文摘In a supporting electrolyte containing 0.6mol/L H_2SO_4,a sensitivity derivative wave of 2-AES is formed by oscillopolarography.The peak potential is-1.01V(vs.SCE),The change of peak height with the concentration of 2-AES is linear in the range from 3.0×10^(-7) to 8.0×10^(-6)mol/L.The detection limit is 1.0×10^(-7)mol/L.The electrode reaction mechanism is discussed.
文摘The indirect voltammetric determination of trace sulfate (2.0×10^(-6)～4.0×10^(-5) mol/L ) with the adsorptive complex wave of lead(Ⅱ)-tetrakis (4-trimethylammonium phenyl) porphyrin (PbTTMAPP) is reported.This method has been used for the analysis of natural waters with satisfactory results.
基金The project supported by the National Natural Science Foundation of China
文摘The voltammetric behaviors of rare earth ions-amino acids were studied.The reduction potential of Eu^(3+) was shifted positively and the peak separation of the cathodic and anodic peaks in cyclic voltammogram de- creased when a certain amino acid was added to Eu^(3+) solution.Experimental results showed that Eu^(3+) was re- duced by way of forming complexes with amino acids which were adsorbed on mercury electrode surface.When histidine and formaldehyde existed simultaneously in the solution containing Eu^(3+),a well-defined reversible catalytic prewave of Eu^(3+) was obtained.Meanwhile,the reduction current of formaldehyde increased greatly with the addition of histidine.The mechanism was studied.Several other rare earth ions and amino acids were also studied preliminarily.
基金We are grateful to the NNSFC (29973026), BNSF (2992007) Foundation for University Key Teacher by the Ministry of Education for the provision of financial support.
文摘Electrochemistry of nitrate reductases (NR) incorporated into 2-aminoethanethiol self-assembled on the gold electrode and polyacrylamide cast on the pyrolytic graphite electrode was examined. NR on chemical modified electrode showed electrochemical cyclic voltammetric responses in phosphate buffers.
文摘The voltammetric behavior of indigo carmine at mercury film electrode on a silver substrate (MFES) was studied in this paper. It was found that indigo carmine gave a sensitive reduction peak at a potential (Vp) of -0.11 V at pH 4.0 in aqueous solution. The MFES gave good reproducibility and life time. The peak currents (ip) depended lipearly on the concentrations of indigo carmine free 0 to 100 ng/ml. The Vp and Ip of indigo carmine at MFES were independent of the concentrations of amaranth at pH 4.0, the Vp of amaranth was -0.24 V at this pH. The differences of Vp between both colorants enabled to distinguish indigo carmine free amaranth.
文摘Electrochemical voltammetric method can;be used to monitor cell health state during its growth. Here we studied the effect of caffeic acid on leukemia cells U937 by the voltammetric behavior of the cells. The result showed that this drug had a negative influence on cell health. which suggests that caffeic acid may be used in inhibition of tumor cells.
基金Project supported by National Natural Science Foundation of China
文摘The voltammetric and polarographic behaviours of 14 rare earth elements were investigated in anhydrous acetone.The influence of residual oxygen on their waves was examined.At a concentration lower than 6× 10^(-4)mol/L,Eu^(3+),Yb^(3+)and Sm^(3+) produce two waves and other rare earth ions exhibit only one wave. When the concentration is greater than 8×10^(-4)mol/L,two waves could be observed on the reduction of Yb^(2+),Sm^(2+)and other RE^(3+)ions except for Eu^(3+).By adding 0.6% H_2O(or 1×10^(-4)mol/L NH_4ClO_4) one well-defined wave appears instead of two.The phenomenon is explained that a thin deposit film may be formed at electrode surface owing to the interaction of RE^(3+) with O_2^-,which is the reduction product of trace oxygen in aprotic solvent.In the presence of a proton donor such as H_2O or NH_4^+,oxygen reduces directly to H_2O_2 and eliminates the appearance of two waves.
文摘The electroanalytical method of ferriheme was studied by linear sweep voltammetry in medium of 0.05 mol/L Tris+0.05 mol/L NH3?NH4Cl buffer at hang mercury drop electrodes (HMDE). Heme exhibits two pair reversible redox peaks and one irreversible peak. The cathodic peak potentials are?;0.236 V, ?0.422 V and ?1.408 V respectively. The first and the third peaks can be used for directly quantitative determination of heme concentrations. The peak currents are good linear relationship with heme concentration in ranges of 3×10?6–6×10?5 mol/L and 3×10?7–1.5×10?5 mol/L respectively.
基金We thank the National Natural Science Foundation of China(Project No.29975033)the NSF of Guangdong Province(Project No.980340)for financial support.
文摘A new method called spline convolution (SC) for resolving overlapped peaks was proposed in this paper. The differential pulse voltammetric overlapped peaks of mixtures of Pb(II) and Tl(I) were investigated by this method, and satisfactory results were obtained. The results show excellent correlation between peak areas of the processed signals and the concentrations.
文摘The rate of voltammetric reduction of Eu(Ⅲ)in acetate solution was increased by the formation of a complex with ribose,lyxose or arabinose.If a ternary complex of Eu(Ⅲ)-D-ribose-L-phenylanaline formed on the surface of mercury electrode,the redox process of Eu(Ⅲ)became more reversible than that of Eu(Ⅲ)-D-ribose in solution phase.
文摘In the 0.3mol/L NH_4Cl supporting electrolyte,salicyl-fluorone exhibits a sensitive adsorptive wave by using linear scanning voltammetry with Ep_1=-0.70V and a diffusion wave with Ep_2=-0.68V(v8,SCE)at pH 2.5.On the surface of HMDE, the adsorption of salieyl-fluorone obeys Frumkin adsorption isotherm.The adsorption coefficient(B),and attractive factor(v)and the amount of saturated adsorption(Γs)have been determined.
文摘Adsorptive enhancements of several inorganic salts on copper(II) were studied by adsorptive stripping voltammetry with a hanging mercury drop electrode Increase in peak curren of cu(II) were observed in alkaline phosphate or media owing to adsorption Silicate can also enhance the peak current of Cu(II). The enhancing power phosphate,carbonate, and silicate is 33, 26, and 8.9 times, respectively.
文摘The electrochemical behavior of N,N-diethyl-p-nitroso aniline was carried out using SWV （square wave voltammetric） at HMDE. A well defined reduction peak was observed at （-0.214） volt versus the reference electrode （Ag/AgC1/sat. KCI）, calibration curve was constructed in phosphate buffer （pH = 7.0）, the relationship is linear within the concentration range 1.283 × 10.5 M - 3.66 × 10.5 M with the correlation （R = 0.9923）. The serial addition ofCPM （chlorpheniramine maleate） leads to the decrease in the reduction current peak （Ip）, quantitatively, the plot of Alp （Ip - Ip） where, Ip： Peak current of N, N-diethyl-p-nitroso aniline alone, lp： peak current of N,N-diethyl-p-nitroso aniline in the presence of CPM, versus concentration is linear within the concentration range 0.984 × 10-6 M - 9.756 × 10-6 M, the correlation coefficient was 0.9954. The method was successfully applied to determine CPM in different types of pharmaceutical formulations, and compared with standard method from British Pharmacopeia [1].
文摘Cyclic voltammetry shows that DBPPH has a pair of cathodic and anodic peaks at Hg electrode.Epc=-1.49 V and Fpa=-1.43 V(vs.Ag/AgCl).The cathodic peak shows adsorptive characteristics.The adsorbed species is DBPPH neutral molecule. The method for measuring trace amount of DBPPH by adsorptive stripping voltammetry is established.
文摘The electroanalytic method of ferriheme was investigated bylinear sweep voltammetry in medium of 0.05M Tris+0.05MNH3-NH4Cl buffer at hang mercury drop electrodes （HMDE）. Hemeexhibits two pair reversible redox peaks and one irreversible peak. Thecathodic peak potentials are -0.236V, -0.422V and -1.408V respectively. The firstand the third peaks can be used for directly quantitative determination of hemeconcentration. The peak currents are good linear relationship hemeconcentration in ranges of 3×10-6～ 6×10-5mol/L and 3×10-7～ 1.5×10-5mol/L respectively. A preliminary discussion on properties of the hemevoltammetric behavior has been suggested.
基金This paper is supported by Serbian Ministry of Education and Science,project number 172030.
文摘Tembotrione is herbicide which belongs to the triketone group of herbicides. It’s registered as a selective, post-emergence herbicide developed for the control of a broad spectrum broadleaf and grassy weeds in corn. There is little information about tembotrione because of his short presence in the market. Due to its ever wider application, it is important to know the details of its chemical characteristics and redox processes, including biogeochemical transformation and migration after application to agricultural land, which could contribute to its efficient and safer application. In this paper we examined voltammetric behavior of tembotrione using Silver/Amalgam (Ag/Hg) electrode. For the investigation of electrochemical behavior we used the cyclic voltammetry technique, with conventional three-electrode cell and electrochemical workstation. During the experiment pH values of solution varieties while constant concentration of tembotrione was maintained. Cyclic voltammograms were recorded at pH values 6, 8, 10 and 12, at which tembotrione was electrochemically active. At this pH values two signals were observed. Optimum pH value, at which the current intensity was greatest, was 12. Obtained results provide relevant information on the electrochemical behavior of tembotrione, which can serve as a basis for the development of electrochemical techniques for the removal and degradation of this pesticide in the environment.
