石墨炉原子吸收光谱法测定茶叶中铅

Determination of lead in tea by graphite furnace atomic absorption spectrometry

目的：探讨茶叶中铅的检测方法,并用该法测定10个样品（含2个标准样品）的Pb含量。方法：应用基体改进剂,用石墨炉原子吸收光谱法测定茶叶中铅。结果：（1）茶叶中Pb含量的测定适宜条件为：磷酸二氢铵作为基体改进剂,灰化温度700℃,原子化温度2000℃;（2）本法铅的检出限为1.1μg.L-1,回收率为94.0%~108.8%;（3）抽检的市售8种茶叶种有2种铅含量大于5mg.kg-1。结论：该法准确灵敏,回收率好,可满足实际检测要求。

Objective： The detection method of lead in tea was disussed,and Pb in 10 samples including 2 standards samples were determined.Methods： With matrix modifier,Pb in tea was determined by graphite furnace atomic absorption spectrometry.Results：（1）The proper conditions for determining Pb were ashing temperature 700℃ and atomizing temperature 2000℃ with NH4H2PO4 as a matrix modifier;（2）DL of Pb in the method was 1.1μg·L-1 and the recovery of the method was ranged from 94.0% to 108.8%;（3）Pb contents of 2 in 8 samples extracted from market were over 5mg·kg-1.Conclusion： This method is accurate and sensitive,it can meet the practical determination requirements.