Simple, accurate, sensitive and validated UV spectrophotometric and chemometric methods were developed for the determination of imidapril hydrochloride （IMD） in the presence of both its alkaline （AKN） and oxidati...Simple, accurate, sensitive and validated UV spectrophotometric and chemometric methods were developed for the determination of imidapril hydrochloride （IMD） in the presence of both its alkaline （AKN） and oxidative （OXI） degradation products and in its pharmaceutical formulation. Method A is the fourth derivative spectra （D4） which allows the determination of IMD in the presence of both AKN and OXD, in pure form and in tablets by measuring the peak amplitude at 243.0 nm. Methods B, C and D, manipulating ratio spectra, were also developed. Method B is the double divisor-ratio difference spectrophotometric one （DD-RD） by computing the difference between the amplitudes of IMD ratio spectra at 232 and 256.3 nm. Method C is the double divisor-first derivative of ratio spectra method （DD-DR1） at 243.2 nm, while method D is the mean centering of ratio spectra （MCR） at 288.0 nm. Methods A, B, C and D could successfully determine IMD in a concentration range of 4.0-32.0 mg/mL. Methods E and F are principal component regression （PCR） and partial least-squares （PLS）, respectively, for the simultaneous determination of IMD in the presence of both AKN and OXI, in pure form and in its tablets. The developed methods have the advantage of simultaneous determination of the cited components without any pre-treatment. The accuracy, precision and linearity ranges of the developed methods were determined. The results obtained were statistically compared with those of a reported HPLC method, and there was no significant difference between the proposed methods and the reported method regarding both accuracy and precision.展开更多
Schiff<sup> </sup>base synthesis is usually acid catalyzed and it usually requires refluxing the mixture of aldehydes and amine in ethanolic solution. Synthesis and characterization of Schiff base ligands ...Schiff<sup> </sup>base synthesis is usually acid catalyzed and it usually requires refluxing the mixture of aldehydes and amine in ethanolic solution. Synthesis and characterization of Schiff base ligands derived from substituted amine and salicylaldehyde and their complexes (Cu<sup>2+</sup>, Co<sup>2+</sup>) are reported. The ligands and ligand-complexes were characterized by melting point, FTIR, CHN-elemental analysis and UV-Visible analysis. The UV-Visible and elemental analysis of complexes established (1:2) mole ratio (M:L). The stability constant and thermodynamic parameters (K, ΔG, ΔH, ΔS) were determined at different temperature (30 - 40)°C which established that the metal-complexes were very stable. The review describes the promising biological<sup> </sup>activities of Schiff base and their metal complexes.展开更多
文摘Simple, accurate, sensitive and validated UV spectrophotometric and chemometric methods were developed for the determination of imidapril hydrochloride （IMD） in the presence of both its alkaline （AKN） and oxidative （OXI） degradation products and in its pharmaceutical formulation. Method A is the fourth derivative spectra （D4） which allows the determination of IMD in the presence of both AKN and OXD, in pure form and in tablets by measuring the peak amplitude at 243.0 nm. Methods B, C and D, manipulating ratio spectra, were also developed. Method B is the double divisor-ratio difference spectrophotometric one （DD-RD） by computing the difference between the amplitudes of IMD ratio spectra at 232 and 256.3 nm. Method C is the double divisor-first derivative of ratio spectra method （DD-DR1） at 243.2 nm, while method D is the mean centering of ratio spectra （MCR） at 288.0 nm. Methods A, B, C and D could successfully determine IMD in a concentration range of 4.0-32.0 mg/mL. Methods E and F are principal component regression （PCR） and partial least-squares （PLS）, respectively, for the simultaneous determination of IMD in the presence of both AKN and OXI, in pure form and in its tablets. The developed methods have the advantage of simultaneous determination of the cited components without any pre-treatment. The accuracy, precision and linearity ranges of the developed methods were determined. The results obtained were statistically compared with those of a reported HPLC method, and there was no significant difference between the proposed methods and the reported method regarding both accuracy and precision.
文摘Schiff<sup> </sup>base synthesis is usually acid catalyzed and it usually requires refluxing the mixture of aldehydes and amine in ethanolic solution. Synthesis and characterization of Schiff base ligands derived from substituted amine and salicylaldehyde and their complexes (Cu<sup>2+</sup>, Co<sup>2+</sup>) are reported. The ligands and ligand-complexes were characterized by melting point, FTIR, CHN-elemental analysis and UV-Visible analysis. The UV-Visible and elemental analysis of complexes established (1:2) mole ratio (M:L). The stability constant and thermodynamic parameters (K, ΔG, ΔH, ΔS) were determined at different temperature (30 - 40)°C which established that the metal-complexes were very stable. The review describes the promising biological<sup> </sup>activities of Schiff base and their metal complexes.
