A derivative ratio spectrophotometric method was used for the simultaneous determination of β-carotene and astaxanthin produced from Phaffia rhodozyma. Absorbencies of a series of the standard carotenoids in the rang...A derivative ratio spectrophotometric method was used for the simultaneous determination of β-carotene and astaxanthin produced from Phaffia rhodozyma. Absorbencies of a series of the standard carotenoids in the range of 441 nm to 490 nm demonstrated that their absorptive spectra accorded with Beer’s law and that the additivity when the concentrations of β-carotene and astaxanthin and their mixture were within the range of 0 to 5 μg/ml, 0 to 6 μg/ml, and 0 to 6 μg/ml, respectively. When the wavelength interval (?λ) at 2 nm was selected to calculate the first derivative ratio spectra values, the first derivative amplitudes at 461 nm and 466 nm were suitable for quantitatively determining β-carotene and astaxanthin, respectively. Effect of divisor on derivative ratio spectra could be neglected; any concentration used as divisor in range of 1.0 to 4.0 μg/ml is ideal for calculating the derivative ratio spectra values of the two carotenoids. Calibration graphs were established for β-carotene within 0?6.0 μg/ml and for astaxanthin within 0?5.0 μg/ml with their corresponding regressive equations in: y=?0.0082x?0.0002 and y=0.0146x?0.0006, respectively. R-square values in excess of 0.999 indicated the good linearity of the calibration graphs. Sample recovery rates were found satisfactory (>99%) with relative standard deviations (RSD) of less than 5%. This method was suc- cessfully applied to simultaneous determination of β-carotene and astaxanthin in the laboratory-prepared mixtures and the extract from the Phaffia rhodozyma culture.展开更多
A new dual-wavelength dual-indicator catalytic kinetic spectrophotometric method for the determination of trace Ru(III)was studied.This method was based on Ru(III)-catalyzing oxidation of Arsenazo I and indigo carmine...A new dual-wavelength dual-indicator catalytic kinetic spectrophotometric method for the determination of trace Ru(III)was studied.This method was based on Ru(III)-catalyzing oxidation of Arsenazo I and indigo carmine by potassium bromate in sulfuric acid.The absorbances of the catalytic and noncatalytic systems were measured at 510 and610 nm,respectively.Under the optimum conditions,the linear range of determination is 0–0.12 lgáml-1and the detection limit is 1.21 9 10-4lgáml-1.The method was applied for the determination of trace Ru(III)in ore samples with satisfactory results.展开更多
A simple,specific,accurate and precise spectrophotometric stability indicating method is developed for determination of bambuterol hydrochloride(BH)in the presence of its degradation product terbutaline(TERB)and in ph...A simple,specific,accurate and precise spectrophotometric stability indicating method is developed for determination of bambuterol hydrochloride(BH)in the presence of its degradation product terbutaline(TERB)and in pharmaceutical formulations.A newly developed spectrophotometric method called ratio difference method by measuring the difference in amplitudes between 245 and 260nm of ratio spectra.The calibration curves are linear over the concentration range of 0.1~1mg·mL-1 for BH and 0.1~0.7mg·mL-1 for TERB with mean percentage recovery of 100.56±0.751 and 99.88±1.183,respectively.The selectivity of the proposed method is checked using laboratory prepared mixtures.The proposed method has been successfully applied to the analysis of BH in pharmaceutical dosage forms without interference from other dosage form additives and the results have been statistically compared with pharmacopeial method.展开更多
The smart novel ratio difference spectrophotometric method was developed and validated for the determination of a binary mixture of Sodium cromoglicate (SCG) and Fluorometholone (FLU) in presence of benzalkonium chlor...The smart novel ratio difference spectrophotometric method was developed and validated for the determination of a binary mixture of Sodium cromoglicate (SCG) and Fluorometholone (FLU) in presence of benzalkonium chloride without prior separation. The results were compared to that of the conventional methods (dual wavelength and first derivative of ratio spectra). The suggested methods were validated in compliance with the ICH guidelines and were successfully applied for determination of SCG and FLU in their laboratory prepared mixtures and commercial ophthalmic solution. The novel method showed significant advantages over the conventional methods regarding simplicity, minimal data manipulation and maximum reproducibility and robustness;which enabled the analysis of binary mixtures with overlapped spectra for routine quality control testing with quite satisfactory.展开更多
[Objective]The aim was to find a way to measure the cholesterol content in deserted oil.[Method]Dual-wavelength spectrophotometry method was used for the determination of cholesterol in edible oil.630 nm and 720 nm we...[Objective]The aim was to find a way to measure the cholesterol content in deserted oil.[Method]Dual-wavelength spectrophotometry method was used for the determination of cholesterol in edible oil.630 nm and 720 nm were set as target band and reference band in this method,respectively.The result was compared to liquid chromatography method.[Result]The relative standard deviation(RSD)was at 1.26% and recovery was between 101.9% and 110.7%.Linear range was 8.0-40.0 μg/ml.The tested result was close to the result of liquid chromatography.[Conclusion]It was proved that this method was easy,fast and accurate.The disturbance of sitosterol was eliminated without isolation.It can be used for fast identification of the authenticity of waste fat.展开更多
A new simple spectrophotometric method was developed for the simultaneous determination of drugs with interfering spectra in binary mixtures without previous separation. The new method is based on a simple modificatio...A new simple spectrophotometric method was developed for the simultaneous determination of drugs with interfering spectra in binary mixtures without previous separation. The new method is based on a simple modification for the ratio subtraction method. This modification enabled wider range of application. The proposed ratio difference method was applied for the determination of brimonidine and timolol in laboratory prepared mixtures with mean percentage recoveries 100.40±2.29 and 101.23± 1.30 respectively, and in their pharmaceutical formulation with mean percentage recoveries 101.08±0.44 and 100.66±0.52 respectively. The suggested ratio difference method was validated according to USP guidelines and can be applied for routine aualitv control testing.展开更多
A simple,specific,accurate and precise spectrophotometric stability indicating method is developed for determination of itraconazole in the presence of its oxidative degradation product and in pharmaceutical formulati...A simple,specific,accurate and precise spectrophotometric stability indicating method is developed for determination of itraconazole in the presence of its oxidative degradation product and in pharmaceutical formulations.A newly developed spectrophotometric method called ratio difference method by measuring the difference in amplitudes between 230 and 265nm of ratio spectra.The calibration curve is linear over the concentration range of 5~25μg·mL-1 with mean percentage recovery of 99.81±1.002.Selective quantification of itraconazole,singly in bulk form,pharmaceutical formulations and in the presence of its oxidative degradation product is demonstrated.The results have been statistically compared with a pharmacopeial method.展开更多
Two simple, accurate, precise and economic spectrophotometric methods have been developed for simultaneous determination of Atorvastatin calcium (ATR) and Ezetimibe (EZ) in their bulk powder and pharmaceutical dosage ...Two simple, accurate, precise and economic spectrophotometric methods have been developed for simultaneous determination of Atorvastatin calcium (ATR) and Ezetimibe (EZ) in their bulk powder and pharmaceutical dosage form. Method (I) is based on dual wavelength analysis while method (II) is the mean centering of ratio spectra spectrophotometric (MCR) method. In method (I), two wavelengths were selected for each drug in such a way that the difference in absorbance was zero for the second drug. At wavelengths 226.6 and 244 nm EZ had equal absorbance values; therefore, these two wavelengths have been used to determine ATR; on a similar basis 228.6 and 262.8 nm were selected to determine EZ in their binary mixtures. In method II, the absorption spectra of both ATR and EZ with different concentrations were recorded over the range 200-350, divided by the spectrum of suitable divisor of both ATR and EZ and then the obtained ratio spectra were mean centered. The concentrations of active components were then determined from the calibration graphs obtained by measuring the amplitudes at 215-260 nm (peak to peak) for both ATR and EZ. Accuracy and precision of the developed methods have been tested; in addition recovery studies have been carried out in order to confirm their accuracy. On the other hand, selectivities of the methods were tested by application for determination of different synthetic mixtures containing different ratios of the studied drugs. The developed methods have been successfully used for determination of ATR and EZ in their combined dosage form and statistical comparison of the developed methods with the reported spectrophotometric one using F and Student’s t-tests showed no significant difference regarding both accuracy and precision.展开更多
基金Project (No. 20276064) supported by the National Natural Science Foundation of China
文摘A derivative ratio spectrophotometric method was used for the simultaneous determination of β-carotene and astaxanthin produced from Phaffia rhodozyma. Absorbencies of a series of the standard carotenoids in the range of 441 nm to 490 nm demonstrated that their absorptive spectra accorded with Beer’s law and that the additivity when the concentrations of β-carotene and astaxanthin and their mixture were within the range of 0 to 5 μg/ml, 0 to 6 μg/ml, and 0 to 6 μg/ml, respectively. When the wavelength interval (?λ) at 2 nm was selected to calculate the first derivative ratio spectra values, the first derivative amplitudes at 461 nm and 466 nm were suitable for quantitatively determining β-carotene and astaxanthin, respectively. Effect of divisor on derivative ratio spectra could be neglected; any concentration used as divisor in range of 1.0 to 4.0 μg/ml is ideal for calculating the derivative ratio spectra values of the two carotenoids. Calibration graphs were established for β-carotene within 0?6.0 μg/ml and for astaxanthin within 0?5.0 μg/ml with their corresponding regressive equations in: y=?0.0082x?0.0002 and y=0.0146x?0.0006, respectively. R-square values in excess of 0.999 indicated the good linearity of the calibration graphs. Sample recovery rates were found satisfactory (>99%) with relative standard deviations (RSD) of less than 5%. This method was suc- cessfully applied to simultaneous determination of β-carotene and astaxanthin in the laboratory-prepared mixtures and the extract from the Phaffia rhodozyma culture.
基金supported by the National Natural Science Foundation of China (No. 51273172)
文摘A new dual-wavelength dual-indicator catalytic kinetic spectrophotometric method for the determination of trace Ru(III)was studied.This method was based on Ru(III)-catalyzing oxidation of Arsenazo I and indigo carmine by potassium bromate in sulfuric acid.The absorbances of the catalytic and noncatalytic systems were measured at 510 and610 nm,respectively.Under the optimum conditions,the linear range of determination is 0–0.12 lgáml-1and the detection limit is 1.21 9 10-4lgáml-1.The method was applied for the determination of trace Ru(III)in ore samples with satisfactory results.
文摘A simple,specific,accurate and precise spectrophotometric stability indicating method is developed for determination of bambuterol hydrochloride(BH)in the presence of its degradation product terbutaline(TERB)and in pharmaceutical formulations.A newly developed spectrophotometric method called ratio difference method by measuring the difference in amplitudes between 245 and 260nm of ratio spectra.The calibration curves are linear over the concentration range of 0.1~1mg·mL-1 for BH and 0.1~0.7mg·mL-1 for TERB with mean percentage recovery of 100.56±0.751 and 99.88±1.183,respectively.The selectivity of the proposed method is checked using laboratory prepared mixtures.The proposed method has been successfully applied to the analysis of BH in pharmaceutical dosage forms without interference from other dosage form additives and the results have been statistically compared with pharmacopeial method.
文摘The smart novel ratio difference spectrophotometric method was developed and validated for the determination of a binary mixture of Sodium cromoglicate (SCG) and Fluorometholone (FLU) in presence of benzalkonium chloride without prior separation. The results were compared to that of the conventional methods (dual wavelength and first derivative of ratio spectra). The suggested methods were validated in compliance with the ICH guidelines and were successfully applied for determination of SCG and FLU in their laboratory prepared mixtures and commercial ophthalmic solution. The novel method showed significant advantages over the conventional methods regarding simplicity, minimal data manipulation and maximum reproducibility and robustness;which enabled the analysis of binary mixtures with overlapped spectra for routine quality control testing with quite satisfactory.
基金Supported by National Quality Inspection Bureau(KJ092102,2009QK146)
文摘[Objective]The aim was to find a way to measure the cholesterol content in deserted oil.[Method]Dual-wavelength spectrophotometry method was used for the determination of cholesterol in edible oil.630 nm and 720 nm were set as target band and reference band in this method,respectively.The result was compared to liquid chromatography method.[Result]The relative standard deviation(RSD)was at 1.26% and recovery was between 101.9% and 110.7%.Linear range was 8.0-40.0 μg/ml.The tested result was close to the result of liquid chromatography.[Conclusion]It was proved that this method was easy,fast and accurate.The disturbance of sitosterol was eliminated without isolation.It can be used for fast identification of the authenticity of waste fat.
文摘A new simple spectrophotometric method was developed for the simultaneous determination of drugs with interfering spectra in binary mixtures without previous separation. The new method is based on a simple modification for the ratio subtraction method. This modification enabled wider range of application. The proposed ratio difference method was applied for the determination of brimonidine and timolol in laboratory prepared mixtures with mean percentage recoveries 100.40±2.29 and 101.23± 1.30 respectively, and in their pharmaceutical formulation with mean percentage recoveries 101.08±0.44 and 100.66±0.52 respectively. The suggested ratio difference method was validated according to USP guidelines and can be applied for routine aualitv control testing.
文摘A simple,specific,accurate and precise spectrophotometric stability indicating method is developed for determination of itraconazole in the presence of its oxidative degradation product and in pharmaceutical formulations.A newly developed spectrophotometric method called ratio difference method by measuring the difference in amplitudes between 230 and 265nm of ratio spectra.The calibration curve is linear over the concentration range of 5~25μg·mL-1 with mean percentage recovery of 99.81±1.002.Selective quantification of itraconazole,singly in bulk form,pharmaceutical formulations and in the presence of its oxidative degradation product is demonstrated.The results have been statistically compared with a pharmacopeial method.
文摘Two simple, accurate, precise and economic spectrophotometric methods have been developed for simultaneous determination of Atorvastatin calcium (ATR) and Ezetimibe (EZ) in their bulk powder and pharmaceutical dosage form. Method (I) is based on dual wavelength analysis while method (II) is the mean centering of ratio spectra spectrophotometric (MCR) method. In method (I), two wavelengths were selected for each drug in such a way that the difference in absorbance was zero for the second drug. At wavelengths 226.6 and 244 nm EZ had equal absorbance values; therefore, these two wavelengths have been used to determine ATR; on a similar basis 228.6 and 262.8 nm were selected to determine EZ in their binary mixtures. In method II, the absorption spectra of both ATR and EZ with different concentrations were recorded over the range 200-350, divided by the spectrum of suitable divisor of both ATR and EZ and then the obtained ratio spectra were mean centered. The concentrations of active components were then determined from the calibration graphs obtained by measuring the amplitudes at 215-260 nm (peak to peak) for both ATR and EZ. Accuracy and precision of the developed methods have been tested; in addition recovery studies have been carried out in order to confirm their accuracy. On the other hand, selectivities of the methods were tested by application for determination of different synthetic mixtures containing different ratios of the studied drugs. The developed methods have been successfully used for determination of ATR and EZ in their combined dosage form and statistical comparison of the developed methods with the reported spectrophotometric one using F and Student’s t-tests showed no significant difference regarding both accuracy and precision.
