Study On The Depuration Of Heavy Metals In Five Kinds Of Benefit Chinese Medicinal Herb

Heavy metals such as lead, cadmium, arsenic and hydrargyrum were confirmed as toxic elements that endanger people's lives. The Chinese medicinal herb (CMH) is often rejected by the foreign countries because the content of heavy metals is beyond of the related standard. And the clinical incidents are happened because of intake of CMH that was polluted by heavy metals seriously. The situation and image of CMH was influenced badly, and the economic loss was not avoided, ether.Cultivation of Green CMH is promoted to reduce the pollution of heavy metals. However the heavy metals have existed in the earth, we have used all kinds of pesticides, fertilizers which usually have heavy metals, and also the plants have the ability to absorb the different kind element. So inevitably, there are heavy metals in CMH. The need to depuration heavy metals in CMH becomes apparent and necessary. In the study, the supercritical fluid extraction was developed to depuration of heavy metals in five kinds of benefit Chinese medicinal herb (BCMH), such as Radix Codoposis, Herba Epimedii, Radix Astragali, Radix Rehmanniae Preparata and Radix Angelicae Sinenisi.1. This is the first time that supercritical fluid extraction was used for the depuration of heavy metals in Radix Codoposis, Herba Epimedii, Radix Astragali, Radix Rehmanniae Preparata and Radix Angelicae Sinenisi, and the condition of supercritical fluid extraction (SFE) for depuration of heavymetals was optimized.Four-factor and three-level orthogonal designs were used to optimize the SFE conditions for depuration of heavy metals in BCMH, and diethyldithiocarbamate (DDC-Na) which forms stable complexes with over 40 metals and non-metals was used as chelating agent for trace metal extraction. High decontamination (more than 85%) and low loss of related composition (less than 5%) in the five kinds of BCHM were received under the best SFE depuration conditions.2.. Establishment of an atomic absorption spectrometry (AAS) method for determination of metal ions in five kinds of BCMH.The samples were decomposed completely in different kinds of strong acid, and then trace lead, cadmium, copper, iron, and zinc were determined by air- acetylene flame AAS, but arsenic and hydrargyrum were detected by hydride-generation AAS. The results of AAS showed that every element had a good linear relationship, recovery and precision. 3. Establishment of the reversed-phase HPLC methods for determination ofthe active constituents in five kinds of BCMH.The determination of the active constituents in BCMH was carried on the C18 columns (250 mm 4.6 mm, Sum). The mobile phase of Radix Codoposis, Herba Epimedii, Radix Astragali, Rehmanniae Preparata and Radix Angelicae Sinenisi were methanol-water(76 : 34,v/v),methanol-water(60 : 40,v/v), acetonitrile-water (30 : 70,v/v), acetonitrile-water(l :' 100,v/v) and 5% formic acid-methanol(80 : 20,v/v), respectively. The detectors were set at 220, 270, 203, 205, 320nm, respectively and carbamazepine was used as the internal standard of Radix Astragali. The methods of HPLC had good accuracy and reproducibility which can be used for the quality control of the five kinds of BCHM.