穿心莲内酯在超临界CO_2萃取中晶体的形成与生长

Crystal formation and growth of andrographolide in supercritical CO_2 extraction

用扫描电镜观察了超临界CO2结晶的穿心莲内酯颗粒微观形貌,并利用液相色谱进行纯度检测,阐述了穿心莲内酯在超临界CO2萃取中晶体在结晶板上成核、生长及分布。结果证实:超临界CO2在萃取釜中能同步萃取结晶穿心莲内酯,且在本实验条件下(压力低于25MPa),晶体纯度在结晶板上呈梯度分布:从下到上,纯度越来越高。

We investigated the morphology of andrographolide particles crystallized in supercritical CO2 extraction by SEM observation and crystal purity by HPLC. The andrographolide crystal nucleation, growth and dispersal were also studied. It was demonstrated that andrographolide could be synchronously extracted and crystallized in extraction container by supercritical CO2. Moreover, when the pressure was less than 25MPa, andrographolide had gradient crystallization distribution on crystal board: the purity of andrographolide became higher from the bottom of crystal board to upside of that. 