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
N, N, N′,N′-ethylenediaminetetrakis(methylenephosphonic acid), EDTPO, was synthesized and char-acterized by element analysis. The reaction of EDTPO with Cu(Ⅱ) formes a stable blue complex with a molarabsorptivity o...N, N, N′,N′-ethylenediaminetetrakis(methylenephosphonic acid), EDTPO, was synthesized and char-acterized by element analysis. The reaction of EDTPO with Cu(Ⅱ) formes a stable blue complex with a molarabsorptivity of 2. 88 × 10￣3 L· mol￣(-1)· cm￣(-1) at 285. 1nm. The composition of the complex is determined tobe 1: 1 . The concentration of Cu (Ⅱ)obeys the Beer′s law from 12. 7μg/ml to 50. 8 μg/ml .Co(Ⅱ), Mn(Ⅱ), Pb(Ⅱ), Cd(Ⅱ), Ca(Ⅱ), Mg (Ⅱ), Cr (Ⅱ) cause a negligible interference except forFe(Ⅱ), Zn(Ⅱ) in the determination of Cu (Ⅱ) with EDTPO. The spectrophotometric determinationof Cu(Ⅱ) is developed. This method is successfully used in determination of Cu(Ⅱ)in anolyte of electrolyticnickel.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
This paper reported an indirect flow injection chemiluminescence （FI-CL） method for the determination of the drugs tetracycline （TC）, chlortetracycline （CTC） and oxytetracycline（OTC） using Cu（ Ⅱ ） as a prob...This paper reported an indirect flow injection chemiluminescence （FI-CL） method for the determination of the drugs tetracycline （TC）, chlortetracycline （CTC） and oxytetracycline（OTC） using Cu（ Ⅱ ） as a probe ion. The CL reaction was induced on-line and after injection of the sample the negative peaks appeared as a result of complexation. The method was applied to the determination of TCs in pharmaceuticals and human urine with recoveries in the range95-105%.展开更多
A new method for determination of Cu（Ⅱ） by DDCT chelating resin preconcentration and thin layer resin phase spectrophotometry was developed. The method has a high sensitivity （ε455= 3.6×10^5L/mol·cm）, ...A new method for determination of Cu（Ⅱ） by DDCT chelating resin preconcentration and thin layer resin phase spectrophotometry was developed. The method has a high sensitivity （ε455= 3.6×10^5L/mol·cm）, which is 33 times higher than that of liquid phase spectrophotometry. It has a good selectivity （most coexisting ions could not influence determination） and an ideal precision [30μg Cu（Ⅱ）, n=6, RSD= l.67%]. The content of Cu（Ⅱ） in water, high purity rare earth and its oxide was determined. The detection limit of Cu（Ⅱ） is 5.3μg/L , and the linear range is 0-7.2μg/ml. The result is satisfactory.展开更多
High concentrations of copper ions(Cu(Ⅱ)) in water will pose health risks to humans and the ecological environment. Therefore, this study aims to utilize ultrasonic-cured modified municipal solid waste incineration(M...High concentrations of copper ions(Cu(Ⅱ)) in water will pose health risks to humans and the ecological environment. Therefore, this study aims to utilize ultrasonic-cured modified municipal solid waste incineration(MSWI) fly ash for Cu(Ⅱ) adsorption to achieve the purpose of “treating waste by waste.” The effects of p H, adsorption time, initial concentration, and temperature on the modified MSWI fly ash’s adsorption efficiency were systematically studied in this article. The adsorption performance of the modified MSWI fly ash can be enhanced by the ultrasonic modification. At pH = 2, 3 and 4, the adsorption capacity of the modified MSWI fly ash for Cu(Ⅱ) increased by 2.7, 1.9 and 1.2 times, respectively. Furthermore, it was suggested that the adsorption process of the modified MSWI fly ash can be better simulated by the pseudo-second-order kinetic model, with a maximum adsorption capacity calculated by the Langmuir model of 24.196 mg.g-1. Additionally, the adsorption process is spontaneous,endothermic, and chemisorption-dominated from the thermodynamic studies(ΔH and ΔS > 0, ΔG < 0).Finally, the enhanced adsorption performance of the modified MSWI fly ash for Cu(Ⅱ) may be attributed to electrostatic interaction and chelation effects.展开更多
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N, N, N′,N′-ethylenediaminetetrakis(methylenephosphonic acid), EDTPO, was synthesized and char-acterized by element analysis. The reaction of EDTPO with Cu(Ⅱ) formes a stable blue complex with a molarabsorptivity of 2. 88 × 10￣3 L· mol￣(-1)· cm￣(-1) at 285. 1nm. The composition of the complex is determined tobe 1: 1 . The concentration of Cu (Ⅱ)obeys the Beer′s law from 12. 7μg/ml to 50. 8 μg/ml .Co(Ⅱ), Mn(Ⅱ), Pb(Ⅱ), Cd(Ⅱ), Ca(Ⅱ), Mg (Ⅱ), Cr (Ⅱ) cause a negligible interference except forFe(Ⅱ), Zn(Ⅱ) in the determination of Cu (Ⅱ) with EDTPO. The spectrophotometric determinationof Cu(Ⅱ) is developed. This method is successfully used in determination of Cu(Ⅱ)in anolyte of electrolyticnickel.
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 %.
文摘This paper reported an indirect flow injection chemiluminescence （FI-CL） method for the determination of the drugs tetracycline （TC）, chlortetracycline （CTC） and oxytetracycline（OTC） using Cu（ Ⅱ ） as a probe ion. The CL reaction was induced on-line and after injection of the sample the negative peaks appeared as a result of complexation. The method was applied to the determination of TCs in pharmaceuticals and human urine with recoveries in the range95-105%.
文摘A new method for determination of Cu（Ⅱ） by DDCT chelating resin preconcentration and thin layer resin phase spectrophotometry was developed. The method has a high sensitivity （ε455= 3.6×10^5L/mol·cm）, which is 33 times higher than that of liquid phase spectrophotometry. It has a good selectivity （most coexisting ions could not influence determination） and an ideal precision [30μg Cu（Ⅱ）, n=6, RSD= l.67%]. The content of Cu（Ⅱ） in water, high purity rare earth and its oxide was determined. The detection limit of Cu（Ⅱ） is 5.3μg/L , and the linear range is 0-7.2μg/ml. The result is satisfactory.
基金supported by the key program of the National Natural Science Foundation of China(52236008).
文摘High concentrations of copper ions(Cu(Ⅱ)) in water will pose health risks to humans and the ecological environment. Therefore, this study aims to utilize ultrasonic-cured modified municipal solid waste incineration(MSWI) fly ash for Cu(Ⅱ) adsorption to achieve the purpose of “treating waste by waste.” The effects of p H, adsorption time, initial concentration, and temperature on the modified MSWI fly ash’s adsorption efficiency were systematically studied in this article. The adsorption performance of the modified MSWI fly ash can be enhanced by the ultrasonic modification. At pH = 2, 3 and 4, the adsorption capacity of the modified MSWI fly ash for Cu(Ⅱ) increased by 2.7, 1.9 and 1.2 times, respectively. Furthermore, it was suggested that the adsorption process of the modified MSWI fly ash can be better simulated by the pseudo-second-order kinetic model, with a maximum adsorption capacity calculated by the Langmuir model of 24.196 mg.g-1. Additionally, the adsorption process is spontaneous,endothermic, and chemisorption-dominated from the thermodynamic studies(ΔH and ΔS > 0, ΔG < 0).Finally, the enhanced adsorption performance of the modified MSWI fly ash for Cu(Ⅱ) may be attributed to electrostatic interaction and chelation effects.
