微波消解试样-火焰原子吸收光谱法测定茶叶中铅和铜

FAAS Determination of Lead and Copper in Tea with Microwave Assisted Sample Digestion

摘要: 采用浓硝酸-过氧化氢(体积比5比1)混合酸对茶叶试样进行消解,用火焰原子吸收光谱法测定其中铅和铜的含量.对消解酸体系、仪器工作条件进行了优化.铅的质量浓度在0.95~3.80 mg·L-1、铜的质量浓度在0.108~0.864 mg·L-1范围分别与其吸光度呈线性关系,检出限(3σ)分别为18.3,15.9 μg·L-1.方法用于分析茶叶试样,铅和铜加标回收率分别为98.8%~102.4%和93.3%~100.0%之间.

Abstract: The tea sample was digested with mixture of conc.HNO3 and H2O2 (5 to 1),and contents of lead and copper in the sample solution was determined by FAAS.Working conditions of instrument were optimized.Linear relationships between values of absorbance and mass concentration of Pb and Cu were obtained in the ranges of 0.95-3.80 mg·L-1 and 0.108-0.864 mg·L-1,with detection limits (3σ) of 18.3 and 15.9 μg·L-1,respectively.Test for recovery was made by standard addition method,and values of recovery found were in the ranges of 98.8%-102.4% for Pb and 93.3%-100.0% for Cu.