A novel method for the determination of captopril by spectrophotometer is described in this paper. The experiment is based on the fact that Fe（Ⅲ） is reduced to Fe（Ⅱ） by captopril, then the in sire formed Fe（Ⅱ...A novel method for the determination of captopril by spectrophotometer is described in this paper. The experiment is based on the fact that Fe（Ⅲ） is reduced to Fe（Ⅱ） by captopril, then the in sire formed Fe（Ⅱ） reacts with potassium ferricyanide to give the soluble prussian blue at pH 4.00, and its maximal adsorption wavelength （λmax） is 735 nm. Good linear relationship is obtained between the absorbance and the concentration of captopril in the wide range of 0.05-20 μg/mL. The linear regression equation is A = -0.04314 ＋ 0.11423C （μg/mL） with a correlation coefficient R = 0.9998. The detection limit （3σ/k） is 0.04 μg/mL, the molar absorption coefficient is 2.5×10^4 L/mol cm. By mensurating the absorbance of soluble prussian blue, the indirect determination of captopril can be obtained. This method has been successfully applied to determination of captopril in pharmaceutical samples. Analytical results obtained are satisfactory.展开更多
A new method was developed for the determination of cefradine by extraction-flotation of CuSCN. The experiment indicated that in the presence of 0.20 mol/L NaOH the degradation of cefradine took place in water bath at...A new method was developed for the determination of cefradine by extraction-flotation of CuSCN. The experiment indicated that in the presence of 0.20 mol/L NaOH the degradation of cefradine took place in water bath at 100 ℃. The thiol group （-SH） of the degradation product could reduce Cu（Ⅱ） to Cu（Ⅰ） for the formation of the emulsion CuSCN in the presence of NH4SCN at pH 4.0. By determining the residual amount of Cu（Ⅱ） in the solution and calculating the flotation yield of Cu（Ⅱ）, the indirect determination of cefradine can be obtained. This method has been applied to determine cefradine in capsules, human serum and urine samples, respectively.展开更多
文摘A novel method for the determination of captopril by spectrophotometer is described in this paper. The experiment is based on the fact that Fe（Ⅲ） is reduced to Fe（Ⅱ） by captopril, then the in sire formed Fe（Ⅱ） reacts with potassium ferricyanide to give the soluble prussian blue at pH 4.00, and its maximal adsorption wavelength （λmax） is 735 nm. Good linear relationship is obtained between the absorbance and the concentration of captopril in the wide range of 0.05-20 μg/mL. The linear regression equation is A = -0.04314 ＋ 0.11423C （μg/mL） with a correlation coefficient R = 0.9998. The detection limit （3σ/k） is 0.04 μg/mL, the molar absorption coefficient is 2.5×10^4 L/mol cm. By mensurating the absorbance of soluble prussian blue, the indirect determination of captopril can be obtained. This method has been successfully applied to determination of captopril in pharmaceutical samples. Analytical results obtained are satisfactory.
文摘A new method was developed for the determination of cefradine by extraction-flotation of CuSCN. The experiment indicated that in the presence of 0.20 mol/L NaOH the degradation of cefradine took place in water bath at 100 ℃. The thiol group （-SH） of the degradation product could reduce Cu（Ⅱ） to Cu（Ⅰ） for the formation of the emulsion CuSCN in the presence of NH4SCN at pH 4.0. By determining the residual amount of Cu（Ⅱ） in the solution and calculating the flotation yield of Cu（Ⅱ）, the indirect determination of cefradine can be obtained. This method has been applied to determine cefradine in capsules, human serum and urine samples, respectively.
