分光光度法测定阿司匹林肠溶片中水杨酸含量

Determination of the Conent of Salicylic Acid in Aspirin Enteric-coated Tablets by Spectrophotometry

建立了分光光度法测定阿司匹林肠溶片中水杨酸的含量。由于阿司匹林分子中无酚羟基不与稀硫酸铁铵溶液作用,而水杨酸分子中含有酚羟基可与之反应生成紫堇色,在酒石酸作稳定剂的乙醇-水溶液中,在526 nm波长处有最大吸收,在该处测定吸收度,计算含量。结果表明:水杨酸在2.5～50μg/mL的浓度范围内线性关系良好,A=12.001C-0.0000221(r=0.99999)。平均回收率98.48%,RSD为0.80%(n=6)。该法操作简便,快速,准确,受外界环境干扰小,适用于阿司匹林肠溶片中微量水杨酸的含量测定。

A method for testing the content of salicylic acid in aspirin enteric-coated tablets by Spectrophotometry was established in the paper. Because of non-phenol hydroxyl in aspirin mocular, so it could not react with thin ammonium ferric sulfate solution. However, the salicylic acid included the phenol hydroxyl with which could be turned to purple. The tartaric acid as the stabilizer in the ethyl alcohol-watery solution was made. The max absorbance was determined at the wavelength of 526 nm, then determined the absorbance and calculated its content. The .result, showed： salicylic acid had a good linear in the concentration range of 2 5-50 μg,/mL（r = 0.99999）. The average recovery was 98.48 %, RSD was 0.80 %. The method was accurate, rapid, simple and especially suitable for the determination of salicylic acid in aspirin enteric-coated tablets.