催化热解-塞曼原子吸收光谱法测定茶叶中的汞

Determination of mercury in tea by catalytic pyrolysis-Zeeman atomic absorption spectrometry

建立催化热解-塞曼原子吸收光谱法测定茶叶中汞含量的方法。将茶叶样品粉碎,过180μm筛,置于进样舟中,热解温度为520~580℃,检测波长为254 nm,采用塞曼原子吸收光谱仪进行测定。汞的质量浓度在0.1~1.0 ng/μL范围内与吸光度有良好的线性关系,相关系数为0.9994,方法检出限为0.1 ng/g。测定结果的相对标准偏差为3.1%~4.2%(n=6),加标回收率为88.5%〜103%。该方法操作简单快速,测定结果准确可靠、灵敏度高且重现性好,适用于茶叶中汞含量的测定。

A method for the determination of mercury in tea by catalytic pyrolysis–Zeeman atomic absorption spectrometry was established.The tea samples were crushed,sieved through 180 μ m sieve and placed in the injection boat.The pyrolysis temperature was 520–580 ℃,and the detection wavelength was 254 nm.The determination was carried out by Zeeman atomic absorption spectrometer.There was a good linear relationship between the mass concentration of mercury and the absorbance in the range of 0.1–1.0 ng/μL,the correlation coefficient was 0.999 4.The detection limit was 0.1 ng/g.The recoveries were 88.5%–103%,and the relative standard deviations were 3.1%–4.2%(n=6).The method is simple,rapid,accurate,reliable,sensitive and reproducible,which is suitable for the determination of mercury in tea.