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采用火焰原子吸收光谱法测定了薏苡仁及白菜中铊的含量。称取样品(5.00 g),加入硝酸-高氯酸(4+1)混合酸20 m L进行湿法消解。试验结果表明,铊的质量浓度在0~3.0 mg/L范围内与其吸光度呈良好的线性关系,相关系数为0.9999,方法的检出限(3 s/k)为0.066 mg/kg,加标回收率为91.6%~95.5%,相对标准偏差(n=7)在1.6%~3.2%之间。该方法可应用于食品中铊含量的测定。
The contents of thallium in Coix seed and Chinese cabbage were determined by flame atomic absorption spectrometry. Weigh the sample (5.00 g) and add 20 mL of nitric acid-perchloric acid (4 + 1) mixed acid for wet digestion. The results showed that there was a good linear relationship between the mass concentration of thallium and its absorbance in the range of 0-3.0 mg / L, the correlation coefficient was 0.9999, and the detection limit (3 s / k) of the method was 0.066 mg / kg. Rates ranged from 91.6% to 95.5% with relative standard deviations (n = 7) between 1.6% and 3.2%. The method can be applied to the determination of thallium content in food.