压力、温度对穿心莲内酯超临界CO_2萃取-结晶的影响

Effect of pressure and temperature on extracting and crystallizing Andrographolide by using supercritical CO_2

以穿心莲浸膏为原料 ,进行了穿心莲内酯的超临界CO2 萃取结晶分离纯化。考察了单因素参数压力、温度对穿心莲内酯纯度、结晶量等的影响。结果表明 :超临界CO2 萃取结晶穿心莲内酯的纯度在结晶板上呈梯度分布 ;在 2 5MPa以下 ,压力升高 ,结晶板上部晶体纯度升高 ,而结晶量先增后减 ;在结晶板下部穿心莲内酯的纯度和结晶量都是先升高后降低 ;温度在一定范围内能提高晶体纯度 ,且有利于缩短萃取结晶时间。

The supercritical CO_2 extraction, crystallization, separation and purificntion of Andrographolide was conducted using Andrographis Paniculata Nees as raw material. The effects of pressure and temperature on extracting purity and crystallizing amount of Andrographolide were studied (purity of andrographolide 30% and 98%) in supercritical CO_2. The results showed that there appeared gradient distribution of crystallization of purity from downside to upside of crystal board; when the pressure is less than 25 MPa, the higher the pressure, the purer the crystal of upside of crystal board. While the pressure increases, the purity and the mass of crystal of downside of the crystal board became higher first, then lower; when the temperature increases, the purity of crystal became higher first, then lower, but to some extent, the higher temperature of extraction and crystallization could improve crystal purity, especially could shorten time of crystallization.