熟地黄中重金属超临界CO_2净化技术研究

Study on the Depuration of Heavy Metals in Radix Rehmanniae preparata

目的:利用超临界 CO_2萃取技术净化熟地黄中重金属。方法:(1)以二乙基二硫代氨基甲酸钠(DDC-Na)为金属络合剂,用超临界流体萃取技术净化药材中的重金属,并对萃取方案进行最优化;(2)选择不同的混酸消化液完全消解药材后,以空气-乙炔火焰 AAS 法和氢化物发生 AAS 法分别测定其中的铅(Pb)、镉(Cd)、砷(As)、汞(Hg);(3)采用 Kromasil C_(18)(250mm×4.6mm,5μm)色谱柱,流动相为乙腈-水(1∶100),流速为1.0mL·min^(-1),检测波长为205nm,灵敏度为1.0AU/V,进样量20μL,测定熟地黄中梓醇的含量。结果:在最佳萃取条件下,重金属净化率达到85%以上,中药材有效成分的损失低于5%。结论:确定了药材中重金属的最佳萃取条件。

Objective：Heavy metals were depurated by supereritical fluid extraction （SFE）in Radix Rehmanniae preparata and the best program was optimized by the orthogonal design. Methods： （ 1 ） Four - factor and three - level orthogonal design was used to optimize the SFE conditions for depuration of heavy metals in Radix Rehmanniae preparata, and diethyldithiocarbamate（ DDC ） was used as chelating agent for trace metal extraction. （ 2 ） The samples were decomposed completely in different kinds of strong acid, and then trace lead, cadmium were determined by air -acetylene flame AAS, but arsenic and hydrargyrum were detected by hydride -generation AAS. （3）The determination of the active constituents in Radix Rehmanniae preparata was carried on the Kromasil C18 （250 mm × 4. 6 mm,5μm） column,the mobile phase was acetonitrile - water （ 1 ： 100） , The detector was operated at 205 nm. Resuits：High decontamination （more than 85% ）and low loss of related composition （less than 5% ）in Radix Rehmanniae preparata,was received under the best SFE depuration condition. Conclnsions：The method may be helpful to solve the problem of heavy - metal - contaminated Chinese herbal medicines.