黄芪中重金属超临界CO_2净化技术研究

目的利用超临界CO2 萃取技术净化黄芪中重金属。方法a 以二乙基二硫代氨基甲酸钠(DDTC)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。b 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) ,以及砷 (As)、汞 (Hg)。c 采用UCTRONVX -ODS(2 5 0mm×4 6mm ,5 μm)色谱柱 ,以乙腈 水 (V∶V =30∶70 )为流动相 ,检测波长为 2 0 3nm ,卡马西平为内标 ,测定黄芪中黄芪甲苷的含量。结果与结论a 确定了药材中重金属的最佳萃取条件。在最佳萃取条件下 ,重金属净化率达到 85 %以上 ;同时 ,中药材中的有效成分损失低于 5 %。b 建立了药材中金属元素和有效成分的含量测定方法 ,为正确评价中药材的质量奠定了基础 ,可用于正确评价净化前后药材的质量变化

Study on the depuration of heavy metals in Radix Astragali

Objective Depurate heavy metals by supercritical fluid extraction(SFE)in Radix Astragali and optimize the best program 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 Astragali,and diethyldithiocarbamate(DDC-Na)was used as a chelating agent for trace metal extraction which forms stable complexes with over 40 metals and non-metals.2.The samples were decomposed completely in different kinds of strong acids,and then trace lead and 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 Astragali was carried out on the UCTRONVX-ODS( 250 mm× 4.6 mm, 5 μm)column.The mobile phase was acetonitrile-water(V∶V=30∶70).The detector was operated at 203 nm,and carbamazepine was used as the internal standard.Results and Conclusions 1.High decontamination(more than 85%) and low loss of related composition(less than 5%)in Radix Astragali were received under the best SFE depuration condition.2.The results of AAS showed that every element had a good linear relationship,recovery and precision.3.The method of HPLC had good accuracy and repeatability which can be used for the quality control of Radix Astragali.4.The methods AAS and HPLC can be used to evaluate the change of the quality in Radix Astragali before or after SFE.5.This is for the first time that SFE-CO 2 was used to depurate heavy metals in Radix Astragali,and it may be helpful to solve the problem of heavy-metal-contaminated Chinese herb medicines.