茶叶及其提取液中重金属cu、pb的检测——毕业论文.doc

苏州科技学院本科生毕业论文I毕业论文：茶叶及其提取液中重金属毕业论文：茶叶及其提取液中重金属 Cu、、Pb 的检测的检测摘摘 要要近年来，茶叶的质量和安全备受关注，而茶叶中的铅铜含量直接关乎饮用者的身体健康本文使用火焰原子吸收光谱测定了铁观音、西湖龙井、碧螺春、黄山毛峰、祁门祁红、信阳毛尖、福建白茶、云南普洱等 8 种茶叶中的 Cu 和 Pb 的含量分别采用酸加热消解和沸水浸泡溶出法处理茶叶样品，确定了两种方法的最佳实验条件，最后对这两种方法进行了比较实验结果表明：所选择的 8 种茶叶中铅、铜的含量都没有超出国家限值，都可以放心使用，并比较得出酸法消解能更准确的测定茶叶中铅、铜的含量关键词 火焰原子吸收光谱；茶叶；酸法消解；沸水溶出苏州科技学院本科生毕业论文IIDetermination of Pb and Cu in teas and its extract AbstractThe quality and safety of teas becomes an important concern of Chinese in recent years. And the contents of Cu and Pb have a directly effect on people’ health. The concentrations of Cu and Pb by Flame atomic absorption spectrometry from eight Chinese teas, that is，Oolong tea, West Lake Longjing, Spring snail, Mount Huangshan Mao Feng, Qimen black tea, Xinyang Maojian tea, Fujian white tea and Yunnan Pu'er. are determined in this thesis. Tea samples are pretreated with acid digestion method and boiled water immersion and extraction method. The optimal pretreatment conditions are selected and the results between mentioned two methods are compared. Our experiments indicates that the concentrations of Cu and Pb from selected tea samples are all below the maximum values of national tea standards and thus safety to be used. Moreover, results from acid digestion are better than those from boiled water extraction. Keywords Flame atomic absorption spectrometry, Tea, Acid degistion , boiled water immersion苏州科技学院本科生毕业论文III目 录1 绪论..........................................................................................................................11.1 铅、铜的测定意义.................................................................................................11.1.1 铅、铜的简介......................................................................................................11.1.2 铅、铜对人体的影响..........................................................................................21.2 研究背景.................................................................................................................41.2.1 相关标准..............................................................................................................41.2.2 各种测定方法......................................................................................................41.3 研究目的.................................................................................................................52 实验部分..................................................................................................................62.1 仪器和试剂.............................................................................................................62.1.1 仪器......................................................................................................................62.1.2 试剂......................................................................................................................62.2 实验内容和方法.....................................................................................................62.2.1 样品......................................................................................................................62.2.2 标准曲线..............................................................................................................72.2.3 实验方法..............................................................................................................72.2.4 加标回收率[8].......................................................................................................83 结果与讨论..............................................................................................................93.1 实验结果.................................................................................................................93.1.1 最佳实验条件确定..............................................................................................93.1.2 标准曲线............................................................................................................113.2 样品测定结果.......................................................................................................113.2.1 酸法消解............................................................................................................113.2.2 沸水溶出法........................................................................................................123.3 加标回收率...........................................................................................................133.3.1 酸法消解测铜的加标回收率............................................................................133.3.2 酸法消解测铅的加标回收率............................................................................133.3.3 沸水溶出法测定铜的加标回收率....................................................................14苏州科技学院本科生毕业论文IV3.3.4 沸水溶出法测定铅的加标回收率....................................................................143.4 方法优越性比较...................................................................................................153.4.1 两种方法测铜优越性比较...........................................................................。