火焰原子吸收光谱法测定茶水中铜、锌元素的含量及冲泡时间对其浸出量的影响

摘要

Objective:To determine the content of copper and zinc in tea by flame atomic absorption spectrophotometry and to investigate the influence on the content after leached for different time. Methods:The tea samples were leached for different time by boiling water and then the content of copper and zinc was determinated by flame atomic absorption spectrophotometry. Results:When the leaching time was less than 10 min, the content of copper and zinc increased significantly with the prolongation of the leaching time, while the increase was not obvious when the leaching time was more than 10 min. Copper and zinc showed good linearity in the range of 0.02-0.15 mg/L and 0.05-0.30 mg/L,separately. The recovery was in the range of 98.5%-101.1%for copper and 98.7%-101.2%for zinc with the RSD of 0.8%in copper and zinc (n=9) . Conclusion:The method is suitable to determine the content of copper and zinc in tea. Leaching time can influence the content of copper and zinc in tea significantly.%目的：采用火焰原子吸收光谱法测定茶水中铜、锌元素的含量，并考察不同浸提时间对其含量的影响，为建立食品微量元素检测方法提供参考。方法：茶叶样品经沸水浸提不同时间后，利用火焰原子吸收光谱法测定其中铜、锌元素的含量。结果：当浸提时间小于10 min时，茶水中铜、锌元素含量随浸提时间的延长而显著升高，10 min后变化不明显；铜元素和锌元素分别在0.02～0.15 mg/L和0.05～0.30 mg/L范围内线性关系良好，加样回收率分别为98.5%~101.1%和98.7%~101.2%，RSD （n=9）均为0.8%。结论：火焰原子吸收光谱法可用于准确测定茶水中铜、锌元素的含量，浸提时间对茶水中铜、锌元素的含量具有显著影响。