石墨炉原子吸收分光光度法测定食品中镉

目的:研究石墨炉原子吸收分光光度法测定食品中镉含量的实验条件及影响因素。方法:采用500℃干灰化法和硝酸、高氯酸混合酸消化法处理样品,以(NH4)3PO4做基体改进剂,采用石墨炉原子吸收分光光度法测定食品中镉含量。结果:方法最低检出限、批内相对标准偏差、批间相对标准偏差和回收率分别为0.014μg/L、2.09%～3.33%、5.79%和92.0%～106%;标准曲线线性范围0.50～4.00μg/L,回归方程Y=0.0506X+0.00999,相关系数r=0.9990。测定国家标准物质(GBW07604,镉标准值:0.32±0.07μg/g)中镉的含量为0.311μg/g,相对误差2.81%。结论:该方法具有较高的灵敏度、准确度和精密度,适用于食品中微量镉的测定。

Determination of Cadmium in Food by GAASThe effect of arsenic to the mice's ability of learning and memory

Objectives: To study GAAS for determination of cadmium in food. Methods: Cadmium in food was determined by GAAS after the samples were burned into ash at 500℃ or digested with mixture of HNO3 and HClO4. During atomization,(NH4)3PO4 was used as modifier to reduce matrix interference. Results: The least detection limit, intra-relative standard deviation, inter-relative standard deviation and recovery of the method is 0.014μg/L, 2.09%～3.33%, 5.79% and 92.0%～106%, respectively. The linear range, regression equation and correlation coefficient of the standard carve were 0.50～4.00 μg/L, Y=0.0506X+0.00999, and r=0.9990, respectively. The concentration and relative error of the standard material (GBW07604) measured by this method were 0.311 μg/g and 2.81%, respectively, which are within the truth value range of standard material (0.32±0.07 μg/g). Conclusion: This method has satisfactory accuracy, sensitivity and precision, and is suitable for measuring cadmium in food.