紫外二阶导数光谱法监测柠檬酸催化合成乙酰水杨酸

目的 采用紫外二阶导数光谱法监测柠檬酸催化合成乙酰水杨酸。方法 选择二阶导数光谱在289 nm和308 nm处的吸光度值,分别建立乙酰水杨酸和水杨酸质量浓度与二阶导数值的标准工作曲线。在不同温度条件下,实时监测合成反应体系中乙酰水杨酸和水杨酸的质量浓度。结果 反应温度为70 ℃、80 ℃、90 ℃和95 ℃,完成反应所需时间分别为80 min、50 min、20 min和15 min。结论 紫外二阶导数光谱法,可以实现对乙酰水杨酸合成过程的监测和判断反应终点。

Monitoring synthesis systems of acetylsalicylic acid with citric acid as the catalyst by second derivative spectrometry

Objective To establish a method for monitoring synthesis systems of acetylsalicylic acid with citric acid as the catalyst by second derivative spectrometry.Methods Respectively, standard work curve of acetyl salicylic acid and salicylic acid were established with second derivative value against concentration at the wavelengths of 289nm and 308nm. Under different temperatures, the real-time content of acetyl salicylic acid and salicylic acid in synthesis reaction system were monitored. Results When the reaction temperature is 70 ℃,80 ℃,90 ℃ and 95 ℃, the complete reaction times were about 80 min, 50 min, 20 min and 15 min individually. Conclusion The second derivative spectrometry method can be achieved on the monitoring and judging acetylsalicylic acid synthesis reaction endpoint.