Natural Cordyceps is one of valued Chinese Medicines (CMs), and its function is described as invigorating lung and kidney, hemostasis and eliminating phlegm according to Chinese Pharmacopoeia (2005). It is known for its efficacy in circulatory, immune, hematogenic, cardiovascular, respiratory and glandular system in modern pharmacological studies. On the other hand, analytical researches about Cordyceps mainly focused on the seeking of biomarkers and the developments of new methods for quality control. However, the investigation of heavy metal, another important aspect of quality control for Cordyceps, was ignored for a long time. In recent years, more attentions have been drawn to heavy metals in CMs. The CMs containing high content of arsenic, lead and mercury are forbidden in many countries, which led enormous economical loss. Therefore, it is essential and crucial for quality contro of CMs such as Cordyceps sinensis. This thesis consists of five chapters: Chapter 1 is the literature review on the research progress of heavy metals in CMs and their speciation analysis. Brief review on natural Cordyceps and its habitat has also been described here. Chapter 2 focuses on the Flame Atomic Absorption Spectrometry analysis of iron and copper, and Graphite Furnace Atomic Absorption Spectrometry analysis of arsenic, cadmium and lead in 13 natural Cordyceps samples from 6 regions. The results showed toxic metals, including arsenic, cadmium and lead, existed in natural Cordyceps, and the contents of arsenic were higher than the limit controlled by "Green Standards of Medicinal Plants and Preparations for Foreign Trade and Economy" Chapter 3 describes the preliminary source analysis of heavy metals in natural Cordyceps. The works included the determination of heavy metals in whole Cordyceps, stroma and dead caterpillar after careful cleaning, as well as several soil samples. The levels of lead, cadmium, iron and copper in Cordyceps samples  were lower after cleaning but that of arsenic was not decreased obviously. The results also showed that the heavy metals in stroma were higher (P<0.05) than in the dead caterpillars except arsenic. Chapter 4 is for arsenic speciation analysis in Cordyceps. The separation of inorganic and organic arsenic was performed according to the national standard extraction method using 6 mol/L hydrochloric acid. Moreover, anion exchange resins were used for the separation of pentavalent and trivalent arsenic. The results showed that the arsenic in Cordyceps was mainly inorganic, and pentavalent arsenic. In summary, quantitative analysis of 5 heavy metals, preliminary source analysis and the further species of arsenic, in natural Cordyceps were investigated, which is helpful to control the quality of Cordyceps.

天然冬蟲夏草為我國名貴中藥，具有補肺益腎，止血化痰等功效，藥理 學硏究也證明冬蟲夏草對人體免疫系統，循環系統以及心腦血管系統疾病具有很好的療效。現代研究不僅開注冬蟲夏草藥理活性，關於有效成分分離，定量分析也常見報導。但是作為品質控制的另一重要方面，蟲草中的重金屬等雜質含量卻一直被人們所忽略。與此同時，關於中藥重金屬含量超標的現狀正成為中藥走向世界的一道門檻。西方社會在接受中醫藥療效的同時，也從未停止過對中藥品質本身的質疑。本文對生長在道地產區的天然蟲草重金屬元素進行了研究，以期探明各元素含量差異及存在狀態，確保中藥用藥安全。 全文包括 5 章： 第一章綜述了有關中藥重金屬的研究現狀，金屬元素形態分析研究進展 及天然蟲草介紹，為本論文交代研究背景與意義。 第二章著重於鉛、砷、鎘、銅、鐵五種元素火焰原子吸收或石墨爐原子吸收分析方法的建立以及各自的方法學考察。完成來自于青海，雲南，西藏，四川，新疆產區以及澳門市場的 13份蟲草樣本的上述元素含量測定。結果顯示有毒金屬鉛，鎘都存在于天然蟲草中，但其含量均未超過我國在《藥用植物及製劑進出口綠色標準》中規定的限量。而另一劇毒元素砷在所有蟲草樣品中的含量都遠遠高於限量 (2 mg/kg)。 第三章對蟲草樣本中被測金屬元素的來源作了初步分析，將選取的蟲草 樣本逐一清理覆在表面的少量雜質塵士後，重新進行測定，並分別對蟲草的蟲體及子座兩部分重金屬進行單獨測定。此外，在本章中還包括六個來自蟲草產地士壤中重金屬含量的測定。結果表明：在經過清理後，鉛和鐵的含量明顯降低，而砷、銅、鎘的含量變化不明顯；蟲體子座中鉛、鎘、鐵、銅的含量均高於蟲體，而砷含量在蟲體部分較高。蟲草產地的土壤中都含有大量上述元素，但土壤與蟲草中金屬含量的相關性在本研究中表現不明顯。 第四章針對蟲草中較高的砷含量，進行砷的形態分析，因為重金屬毒性與形態價態密切相關。實驗採用國標方法對蟲草中的無機砷進行提取，分別 作無機總砷與有機總砷的測定，繼而對無機砷提取液採用強鹼性陰離子交換 樹脂吸附的方法使三價砷與五價砷分離並測定。結果表明蟲草中的砷主要以無機的五價砷的形式存在。 總之，本文對各道地產區的天然冬蟲夏草中鉛、砷、鎘、銅、鐵五種重金屬元素做了較系統的分析；並對其中各元素來源進行初步分析；最後針 含量高的砷元素，進行形態分析，其目的是了解天然蟲草中的重金屬存在狀況，為中藥品質控制提供依據，以保證蟲草用藥的安全性。