4-氨基安替比林衍生显色光度法测定硫酸特步他林

Spectrophotometric determination of terbutaline sulfate using 4-aminoantipyrine as the chemical derivative chromogenic reagent

研究了铁氰化钾存在下,4-氨基安替比林与硫酸特步他林相互作用所引起吸收光谱的变化,建立了简便、快速测定药物中硫酸特步他林的新的分光光度法。在碱性介质中,铁氰化钾氧化硫酸特步他林的生成物可与4-氨基安替比林发生缩合反应,生成紫红色4-氨基安替比林衍生物,摩尔比为1:2,表观摩尔吸收系数和稳定常数分别为2.27×10~4L·mol^(-1)·cm^(-1)和2.80×10~9。测定体系最大吸收波长556 nm处的吸光度,可测定硫酸特步他林的含量,并探讨其反应机理。硫酸特步他林的浓度在0.256~19.2μg·mL^(-1)范围内与体系的吸光度呈良好的线性关系,其线性回归方程为A=0.0059+0.04138 c(μg·mL^(-1)),线性相关系数r=0.9999。方法的检出限和精密度的相对标准偏差分别为0.15μg·mL^(-1)和1.4%。将方法应用于硫酸特步他林片中硫酸特步他林含量的测定,加标后平均回收率在97.5%以上。

The change of absorptive spectra caused by the interaction of terbutaline sulfate with 4-aminoantipyrine in the presence of potassium hexacyanoferrate(Ⅲ) has been studied by spectrophotometric method. A fast and simple method for the determination of terbutaline sulfate was developed The results indicated that in alkaline solution,the oxidation product of terbutaline sulfate can form purple-red condensation reaction complex with 4-aminoantipyrine. Its maximum absorption wavelength and the apparent molar absorption coefficient of determination of terbutaline sulfate were 556 nm,and 2. 27× 10~4L·mol^(-1)cm^(-1),respectively,when the stoichiometric ratio of the reaction was 1: 2. The reaction mechanism was studied preliminary and stability constant of the complex was2. 80×10~9. Beer's law was obeyed in the range of 0. 256 ~ 19. 2 μg·mL^(-1)of terbutaline sulfate.The data have been filled to a linear regression equation A = 0. 0059 + 0. 04138 c(μg·mL^(-1)),with the correlation coefficient of 0. 9999,the apparent molar absorption coefficient of determination of terbutaline sulfate is 2. 27 × 104L·mol^(-1)cm^(-1). The limit of detection is 0. 15 μg·mL^(-1),while R.S.D. 1. 4%. The proposed method has been applied to the determination of terbutaline sulfate in pharmaceutical samples with average recovery rate over 97. 5%.