超声波提取法测定茶叶中锌 铁 铜 锰

目的探索超声提取茶叶中Zn、Fe、Cu、Mn 4种元素的最佳试验条件,建立一种方便、快捷地提取茶叶中金属元素的方法。方法分别采用超声波提取和湿消化法提取茶叶样品中的Zn、Fe、Cu、Mn 4种微量金属元素,并用火焰原子吸收光谱法测定样品中各元素的含量,重点考察了超声波提取法中盐酸提取液浓度、超声时间和超声温度对各金属元素提取效率的影响。结果两种前处理方法处理样品后测得结果一致性较好,测定结果的RSD均〈10%,加标回收率均在90%~105%之间。结论湿消化法和超声波提取法均可较好的用于茶叶样品中Zn、Fe、Cu、Mn的提取,而且超声波提取法仅使用稀酸、所需温度低、操作简便快速,是一种值得推广的快速样品前处理方法。

The ultrasonic extraction technology for the determination of zinc,iron,copper and manganese in tea

Objective To explore the best experimental conditions for an ultrasonic extracting zinc,iron,copper and manganese and obtain a convenient and quick extraction of metallic elements in tea.Methods The zinc,iron,copper and manganese in tea were extracted by ultrasonic extraction methods and wet digestion respectively,and determined by Flame Atomic Absorption Spectrophotometry.The effects of several key operational parameters including the concentration of HCl,ultrasonic time and ultrasonic temperature in the ultrasonic extraction method were optimized.Results There are good coherence between two pretreatments,the RSD of determination results were below 10%,and the recoveries between 90%~105%.Conclusion The ultrasonic extraction method has some merits,such as use of diluent acid,low temperature and fast operation,which means a good alternative to conventional pretreatments for extraction of metallic elements in tea.