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目的建立检测米粉中镉含量的微波消解-石墨炉原子吸收光谱法,并对测定条件进行优化选择,达到快速、准确检测的目的。方法采用微波消解对米粉样品进行前处理,实验中以磷酸二氢铵为基体改进剂,通过优化灰化温度和原子化温度,在228.8 nm共振线,应用石墨炉原子吸收法测定米粉中镉的吸光度值,与标准系列比较定量。结果镉在0~4μg/L范围内线性关系良好,相关系数为0.999 1;最佳灰化温度为800℃,最佳原子化温度为1 200℃;方法检出限为0.065μg/L;精密度(RSD)为1.87%(n=6);回收率为95.5%~104.0%。结论微波消解石墨炉原子吸收法具有操作简便、快速、灵敏度高等特点,并有较高的回收率,能适用于米粉中镉的测定。
Objective To establish a microwave digestion - graphite furnace atomic absorption spectrometry (FAAS) for the determination of cadmium in rice flour, and to optimize the determination of the determination conditions to achieve rapid and accurate detection. Methods Microwave digestion was used to pretreat the rice noodles. In the experiment, ammonium dihydrogen phosphate was used as the matrix modifier. The ashing temperature and atomization temperature were optimized. At 228.8 nm resonance line, graphite furnace atomic absorption spectrometry Absorbance value, compared with the standard series quantitative. Results The linearity of cadmium in the range of 0-4μg / L was good with a correlation coefficient of 0.999 1. The optimal ashing temperature was 800 ℃ and the optimum atomization temperature was 1 200 ℃. The detection limit was 0.065 μg / L. The degree of RSD was 1.87% (n = 6). The recoveries ranged from 95.5% to 104.0%. Conclusion Microwave digestion graphite furnace atomic absorption method has the advantages of simple, rapid, high sensitivity and high recovery rate, which can be applied to the determination of cadmium in rice flour.