Study On The Determination Of Pesticide And Heavy-Metal Residues From The Extracted Of Ginseng

This article discusses the current status and types of pesticide contaminants found in plant material used to make Chinese herbal medicines in China. Research on maximum residue limit (MRL) standards for pesticide and heavy metals residues in Chinese herbal medicine plant material is also discussed. Feasible suggestions are proposed for dealing with the problem of pesticide and heavy metals residues exceeding standard levels allowed in plant material used for Chinese herbal medicine.With the development of Chinese Medicines, the quality of Chinese Medicines and their products is taken seriously by People. However, in the process of planting Chinese medicinal materials, because of remained agricultural chemicals in soil due to massive and long-term application of chemistry and polluted environment, pesticide and heavy metals in traditional Chinese medicines exceed those in the allowed standard. Thus the quality of Chinese native medicine and product quality is affected seriously. Chemistry has become one of main sources of pollution to Chinese medicines.At present, the study of detection and analysis from the pesticide and heavy metals in traditional Chinese medicines was concentrated relatively, and the study of the removal from them was few. So the effective removal of pesticide residues and heavy metals in the way, it is very necessary.The research has established the method which determines 10 kinds of organophosphorus pesticide, 4 kinds of organochlorine pesticide and 2 kinds of pyrethroid pesticide residues in the extracted ginseng by GC simultaneously. Pesticide residues were extracted from the extracted with acetone and n - hexane. Liquid - liquid extraction was performed with n - hexane and the clean - up of the extracted were made with alumina neutral - florisil column. Analytical screening was determined with internal-standard method by gas chromatography using capillary column equipped with electron - capture detector. The recovery obtained from the samples of the extracted of ginseng( n = 3) at three concentration levels was in the ranges of 82.32%～115.3% , with relative standard deviations of 1.5%～8.7%. Detection limit was from 0.005 to 0.007mg·kg^-1 for organochlorines, 0.005 to 0.009mg·kg^-1 for organophosphorus and 0.005 to 0.008mg·kg^-1 for pyrethroids, respectively.The method with determining 7 kinds of heavy metals by atomic absorption spectrophotometry was set up. The samples were digested with HNO₃-HClO₄. The determining method was acetylene-flame and hydride generation atomic absorption spectrometry. The recovery obtained from the samples was in the ranges of 85.37% -120.1%, with relative standard deviations of 2.7%-11.4%.The establishing research was determined Ginsenoside Rg₁, Rb₁ and Re in the extracted ginseng by HPLC simultaneously. Ginsenosides were extracted from the extracted with 70% alcohol. Liquid - liquid extraction was performed with H₂O saturated n BuOH and the residue was dissolved with methanol. The medthod was used the Diamonsil C₁₈ column, the acetonitrile-0.1% phosphoric acid solution as the mobile phase with gradient elution( pH=6.0,adjusted with triethylamine), the UV detector was set at 203 nm and the flow rate of 0.8mL·min^-1. The recovery obtained from the samples was in the ranges of 87.02%～102.3% , with relative standard deviations of 1.0%～2.5%. Detection limit was from 0.2350 to 4.700μg·g^-1 for Rg₁, 0.2300 to 4.600μg·g^-1 for Rb₁ and 0.2000 to 4.000μg·g^-1 for Re, respectively.Through near 50 kinds of macroporous resin screening, the method optimizes the removal condition of the ginseng extraction's pesticide and heavy metals residues with orthogonal test by the loss rate of the ginseng's effective ingredient. The optimum condition is A₁B₃C₃D₂. the resin weight is 20 gram, the extract flows 0.5V/0.5h, the washing water is 1 volume, and the washing water speeds 1V/h.The results of research show that the recommended method is simple, reproducible, and can be used in testing pesticide residues in other extracts of Chinese medicinal materials. Therefore the method will be a great benefit to enhancing the quality of Chinese medicinal materials and Chinese traditional patent medicine, as a result impelling internationalization of Chinese native medicines.