茶叶中铅含量的测定

Determination of lead content in tea

中文关键词:  茶叶  铅含量  检出限  加标回收率

英文关键词:tea  lead content  limit of detection  spiked recovery rate

中文摘要:

      目的 建立高效、准确的茶叶中铅含量测定方法。方法 采用干法灰化、湿法消解和微波消解3种方法处理茶叶样品, 并使用石墨炉原子吸收光谱法和电感耦合等离子体发射光谱法(inductively coupled plasma atomic emission spectrometry, ICP-OES)分别对茶叶样品中铅含量进行检测, 并对各检测方法进行比较分析。结果 在铅含量的检测区间内, ICP-OES法的最低检出限比石墨炉法高20多倍。使用石墨炉法检测, 3种消解方法的加标回收率顺序为: 微波消解法＞湿法消解＞干法灰化。结论 微波消解-石墨炉法高效、准确、可靠, 可用于茶叶中铅含量进行检测。

英文摘要:

      Objective To establish a method for determination of lead content in tea. Methods The tea samples were treated by three methods of dry incineration, wet digestion and microwave digestion, and the lead contents were detected by graphite furnace atomic absorption spectrometry (GFAAS) and inductively coupled plasma atomic emission spectrometry (ICP-OES). Results In the detection of lead content in the interval, the lowest detection of the ICP-OES was over 20 times higher than that of GFAAS. In the detection of lead content by GFAAS, the recovery rates in ascending order of three methods were as follows: microwave digestion, wet digestion and dry incineration. Conclusion The method of microwave digestion-GFAAS is efficient, accurate and reliable, which can be used for the determination of lead contents in tea.