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Metal Elements’ Enrichment, Measurement and Transference in Decoction Fluid of Edible Biologic Chinese Medicines

Author: YangXianZhen
Tutor: ChenXueZe
School: Central South University of Forestry Science and Technology
Course: Agricultural Products Processing and Storage
Keywords: Pre-Concentration Atomic Absorption Edible biologic medicines Heavy metal Trace element
CLC: R284.1
Type: Master's thesis
Year: 2007
Downloads: 46
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Abstract

Atomic Absorption Spectrometry (AAS) is one of most effective analytical methods for determination of heavy metal ions in edible biologic medicines,and it is highly sensitive, selective, operational easily and time-saved. But it must be pretreated by dry ashing or wet digestion process with the sample before determination. The sample is easily polluted and the determining ingredient is easily lost, and its operation is complex with time wasted. Suspension Sampling Atomic Absorption Spectrometry can effectively solve these problems. The trace elements of the samples can be determined rapidly and accurately by this method. Flame Atomic Absorption Spectrometry (FAAS) or Graphite-furnace Atomic Absorption Spectrometry (GFAAS) may not determine the trace heavy metals sometimes, it must be pre-concentrated with the sample before the determination. Now, there are many methods of pre-concentration and separation for the trace heavy metals that can be used in AAS, such as extraction separation, co-precipitation process, activated carbon adsorption method, separating and enriching of sulfhydryl cotton, ion exchange process and so on. This thesis applies a new simple and sensitive method to determination of trace Cadmium, Copper and Lead in liquor of Edible biologic medicines which is Pre-Concentration Graphite-furnace Atomic Absorption Spectrometry. The paper is as follows:Chapter One, reviewed the current situation and development tendency of edible biologic medicines and determination of heavy metals, explain the significance by using the way of Pre-Concentration Graphite Furnace Atomic Absorption Spectrometry to determine the trace Cadmium, Copper and Lead in liquor of edible biologic medicines.Chapter Two, a simple and sensitive method has been developed for the determination of Cadmium, Copper and Lead in liquor of Chinese medicine. The Cadmium, Copper and Lead were fixed on finely divided silica gel as the complex with ammonium pyrrolidinedithio carbamate (APDC) and the silica gel was collected on a membrane filter by filtration under suction, then wash down the silica gel used 1 moL/L hydrochloric acid from membrane filter paper. The suspension was directly subjected to the determination by Graphite-furnace Atomic Absorption Spectrometry. When n=5, for Cadmium standard deviation (SD) of these samples were from 0.0036 to 0.0058 and recoveries added were 91.8% and 111.1%;for Copper, SD were from 0.0045～0.0099 and recoveries added were 96% and 98%; for Lead, SD were from 0.0052～0.0130 and recoveries added were 95.3% and 108%.The results were comparatively satisfied.Chapter Three, in this chapter research was taken on the removal patterns of Cadmium, Copper and Lead in liquor of Chinese medicine at different soaking time by the way of Pre-Concentration Graphite-furnace Atomic Absorption Spectrometry. As the results:by soaking 10～60 min, the value of determination of Cadmium, Copper and Lead in four kinds of edible biologic medicines show the irregular change, but all of them reach the top when soaking 60min, so as a factor of consideration, comparing to the original medicine we could formulate different limited standard for heavy metal ions of edible biologic medicines in the daily drinks.Chapter Four, after wet digestion HNO3:HClO4 5:1, determinated Ca、Mg、Zn、Fe、Na、Mn in four kinds of simple by Air-C2H4-Flame Atomic Absorption Spectrometry. For every sample, we parallel determinates 5 times, the relative standard deviations were within 2.0%, The standard recoveries were in range of 95.6～104.3%. As the results, in four kinds of edible biologic the medicines, the content of Ca、Mg、Fe、Na are highest in honeysuckle, the content of Zn is highest in medlar; the content of Mn is highes in flos chrysanthemi.

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