【作者】 褚卓栋；

【导师】 刘文菊； 张桂银；

【作者基本信息】 河北农业大学 ， 土壤学， 2008， 硕士

【摘要】 本论文通过对中草药种植区土壤、各生产阶段中草药及中成药样品的分析,旨在揭示中药(本文中指中草药和中成药)外源重金属(本文的主要研究对象为铅、镉、砷、汞,砷因其对生物的毒性与重金属元素相似,为行文方便包括在“重金属”之列)的主要来源;通过人工胃肠体外模拟系统(In Vitro test)对中草药和中成药重金属的人体生物可给性进行探索性研究;并在此基础上对中药中砷、汞对人体的健康风险进行了初步的评价。主要研究结果如下:(1)中草药种植区土壤重金属含量分析通过预试验,筛选出硝酸—双氧水体系为土壤重金属铅、镉、砷、汞全量分析的最适消解酸体系,采用高压密闭消解,石墨炉原子吸收法和氢化物发生—原子荧光光谱法分别分析中草药种植区土壤样品中铅、镉、砷、汞含量。结果表明,各采样点土壤样品铅、镉、砷、汞含量均符合或优于《国家土壤环境质量标准》二级标准。(2)中草药对土壤中重金属的富集及重金属主要来源分析通过对中草药药用部位重金属富集系数的分析发现,不同中草药对重金属的富集能力存在差异。各种中草药对于四种重金属的富集系数范围分别为铅:0.01～0.07,镉:0.20～1.17,砷:0.01～0.04,汞:0.72～2.97。对不同生产阶段中草药重金属含量的分析显示,绝大多数(95%)草药样品的重金属铅、镉、砷、汞含量低于《药用植物及制剂外经贸绿色行业标准》的相关限量标准。在采收—晾晒、储运—加工和炮制过程中,约80%中草药重金属含量未表现出明显变化(如白芷、北沙参等),说明其所含重金属主要来自种植过程中对土壤中重金属的吸收,且含量较低;而部分(约20%)中草药在上述过程中重金属含量呈增加趋势(如知母、天花粉),说明这部分中草药在这一过程中容易受到外源重金属的污染,特别是在加工、炮制阶段。(3)含雄黄、朱砂复方中成药中砷、汞含量分析结果显示:含雄黄中成药样品中砷全量为9.9×10~2～8.8×10~4mg/kg,均超过2.0mg/kg的砷限量标准值;同时含雄黄、朱砂中成药中砷全量范围9.2×10~3～1.2×10~5mg/kg,汞全量为5.0×10~3～3.5×10~4mg/kg,均超过0.2mg/kg的标准值。(4)中草药—中成药中砷、汞生物可给性的研究中草药中砷、汞生物可给性结果分析显示:不同中草药品种中砷、汞的生物可给性差异较大。各中草药粉末样品中砷的胃阶段生物可给性范围为5.75%～85.31%,小肠阶段为7.84%～66.03%;对于煎煮后样品,砷的胃阶段生物可给性范围为11.29%～51.31%,肠阶段为17.57%～44.19%;对于中草药粉末中的汞,胃阶段生物可给性范围为10.96%～68.04%,肠阶段范围5.78%～43.11%;对于煎煮样品,胃阶段生物可给性范围在5.24%～46.37%,肠阶段为2.48%～23.07%。含雄黄中成药砷的生物可给性在胃阶段为0.20%～2.17%,小肠阶段砷可给性在0.26%～2.43%范围内;同时含雄黄、朱砂中成药中砷的生物可给性在胃阶段为0.37%～5.23%,小肠阶段为0.36%～5.94%。汞的生物可给性在胃阶段为0.002%～0.057%,肠阶段砷可给性在0.002%～0.048%范围内。(5)中草药、中成药中砷、汞的健康风险初步评价以世界卫生组织每日允许摄入量(ADI)为标准,对中草药中重金属人体风险评价,结果表明:总体上砷、汞两元素,总量、肠阶段草药粉末可给含量及肠阶段煎煮样品的可给含量所对应的人体健康风险依次降低。对于砷元素而言,由于中草药中较高的砷可给性,即使经煎煮处理的某些样品,还是对人体的健康具有一定的风险;而对于汞,由于其在中草药中可给性很低,所分析的样品中汞对于人体健康基本不存在风险。对含雄黄、朱砂等重金属矿物成分的中成药中砷、汞人体健康风险评价结果显示:若以全量结果衡量,所有含雄黄的中成药均对人体健康具有巨大风险;以小肠阶段可给砷含量评价,其数值与ADI比值范围为11.2%～774.49%,约70%的成药中可给砷含量仍然足以威胁人体健康;对于同时含有雄黄和朱砂的中成药,其中可给砷与ADI比例为1.48%～879.68%。对于汞虽然其全量高出限量标准数万至十数万倍,但对人体风险很小。更多还原

【Abstract】 The concentrations of Arsenic（As）, Cadmium（Cd）, Mercury（Hg） and Lead （Pb） in soil, Chinese herbal medicines and Chinese patent medicines were investigated respectively. Furthermore, an In Vitro gastrointestinal digestion test was used to assess the bioaccessibility of arsenic and mercury in some Chinese herbal medicines which accumumate higher concentrations of arsenic and Hg and each patent medicine. After gastrointestinal digestion, preliminary Health Risk Assessment （HRA） of arsenic and mercury was conducted comparing to ADI（Acceptable Daily Intake） from WHO（World Hygienic Organization）. The resules showed as follows:（1） Concentrations of heavy metals in soils from herbal medicine cultivated regionsHNO₃-H₂O₂ digested acidic systerm was selected for the higher recovery of Pb, Cd, arsenic and Hg using the reference materials of soil. Soil samples were digested in high pressure vessels to measure the concentrations of arsenic, Hg, Pb and Cd. Arsenic and Hg were determined with HG-AFS, Pb and Cd were measured with GF-AAS. Compared with Environmental Quality Standard for soils-GB15618-1995, the concentrations of heavy metals in soils from herbal medicine cultivated regions were lower than the Quality Standard II class and did not exceed the safety limitation.（2） The concentrations of heavy metals in Chinese herbal medicinesThe results showed that different herbal medicine have different Bioconcentration Factor. The area of Bioconcentration Factor result were:Pb 0.009-0.07, Cd 0.20- 1.17, arsenic 0.008-0.04, Hg 0.72-2.97.The concentrations of heavy metals in herbal medicines from each working procedure were determined. The concentrations of four heavy metals in the great majority（about 95%） of herbal medicines could match with green standards of medicinal plants and preparations for foreign trade and economy （WM2/T-2003）, there was little difference among the concentrations of heavy metals in herbal medicines during the whole process. However, the concentrations of Pb, Cd, arsenic and Hg increaesd in some samples （about 20%） sample step by step. Therefore, the processing may become the main source of heavy metals in some herbal medicines. （3） Concentrations of arsenic and Hg in the Chinese patent medicines with realgar or cinnabarThe concentrations of arsenic and Hg in Chinese patent medicine with realgar or cinnabar were 9.9×10²-1.2×10⁵mg/ kg and 5.0×10³-3.5×10⁴ mg/kg respectively, much higher than the standards （WM2/T-2003）.（4） Bioaccessibility of arsenic and Hg in Traditional Chinese medicines （TCMs）Bioaccessibilities of arsenic and Hg in powder of herbal medicines were 5.75%-85.31% and 10.96%-68.04% at the gastric phase, were 7.84%-66.03% and 5.78%-43.11% at intestine phase respectively. Moreover, bioaccessibilities of arsenic and Hg in the hot exreactable solition of herbal medicines were 11.29%-51.31% and 5.24%-46.37% at the stomach phase, and were 17.57%-44.19% and 2.48%-23.07% at intestine phase respectively. In general, bioaccessibilities of arsenic and Hg in the stomach phase were higher than thoes of intestine phase, and arsenic and Hg showed higher bioaccessibilities in herbal medicine powder than in decoctions.In Chinese patent medicines with realgar, arsenic bioaccessibilities were 0.20%-2.17% in stomach phase, and 0.26% - 2.43% in intestine phase. In Chinese patent medicines with both realgar and cinnabar, arsenic bioaccessibilities was 0.37%-5.23% in stomach phase, and 0.36% - 5.94% in intestine phase. Hg bioaccessibilities were 0.002%-0.057% in stomach phase, and 0.002%-0.048% in intestine phase.（5） Preliminary Health Risk Assessment of heavy metalds in TCMsThe health risk of arsenic and Hg decreased according to the ranking: total concentrations in herbal medicine > available concentrations of powder > available concentrations of extractable solution of herbal medicines. Hg in herbal medicines had little risk to human health, but arsenic in some herbal samples showed much higher risk to human health.And in most of （about 70%） Chinese patent medicines, arsenic showed high health risk, but Hg had little health rish to human.In conclusion, TCMs could be contaminated with exterior source of heavy metals from every working procedures, and the preparation and processing procedure were the main sources of heavy metals accumulated in some herbal medicines. Realgar added in Chinese patent medicines may make a serious health risk to human body. However, there was no significant health risk of Chinese patent medicine with cinnabar.更多还原