紫外多波长光谱法监测阿司匹林合成过程的水杨酸和阿司匹林

建立测定阿司匹林合成过程中水杨酸、阿司匹林含量和转化率的分析模型。采用紫外多波长扫描乙醇溶液中阿司匹林和水杨酸的紫外光谱,建立水杨酸和阿司匹林紫外光谱的向量长度与其质量浓度的标准曲线,通过斜投影算法分离出待测样本中阿司匹林和水杨酸的紫外光谱。计算光谱向量长度,代入标准曲线得到待测样本中阿司匹林和水杨酸的含量。实验结果表明,水杨酸、阿司匹林的质量浓度与其紫外光谱的向量长度呈良好的线性关系,线性范围分别为2.00~40.00,10.00~200.00μg/m L。水杨酸和阿司匹林测定结果的相对标准偏差为0.16%~2.19%(n=5),加标回收率在93.3%~106.9%之间。该方法快速简便、准确可靠,可满足阿司匹林和水杨酸的同时测定及反应过程中水杨酸转化率监测要求。

Monitoring Salicylic Acid and Aspirin in Synthesis Systems of Aspirin by Muti-Wavelength Ultraviolet Spectroscopy

In order to establish the analysis model for the quantitative determination of salicylic acid and aspirin in synthesis systems of aspirin, a method based on quantitative relation between length of ultraviolet spectroscopy vector and concentration was developed. Pure spectrum of salicylic acid and aspirin in testing sample were separated through oblique projection method. The experimental results showed that the mass concentration of salicylic acid, aspirin and its ultraviolet spectral vector length had good linear relationship in the range of 2.00-40.00, 10.00-200.00μg/mL, respectively. The relative standard deviation of determination results was 0.16%-2.19%(n=5), and the recoveries ranged from 93.3% to 106.9% for salicylic acid and aspirin. The method is quick and simple, accurate and reliable, so it can meet the requirments of simultaneous determination of aspirin, salicylic acid and salicylic acid conversion in reaction process monitoring.