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目的:探讨微波消解-石墨炉原子吸收法检测大米样品中痕量镉的快速分析方法。方法:对大米样品采用硝酸-微波消解和以及消解后高温快速赶酸的方法进行前处理,以0.5%硝酸钯-0.5%磷酸二氢铵混合液为基体改进剂,石墨炉原子吸收光谱法进行测定,标准曲线法进行定量。结果:镉标准溶液质量浓度在0 ng/ml~2 ng/ml范围内线性关系较好,相关系数r为0.9994,方法加标回收率为87.1%~92.6%,相对标准偏差(RSD)小于5.0%。结论:该方法操作简便,安全,快速,精密度、准确度较高,适用于大米中微量镉的测定。
Objective: To explore a rapid method for the determination of trace cadmium in rice by microwave digestion - graphite furnace atomic absorption spectrometry. Methods: The rice samples were pretreated by nitric acid-microwave digestion and digestion at high temperature, followed by rapid acid catalysis. The samples were treated with 0.5% palladium nitrate-0.5% ammonium dihydrogen phosphate as matrix modifier and graphite furnace atomic absorption spectrometry Determination, standard curve method for quantification. Results: The linearity of cadmium standard solution was good in the range of 0 ng / ml ~ 2 ng / ml with the correlation coefficient r of 0.9994. The recoveries of the standard solutions were 87.1% ~ 92.6% and the relative standard deviations (RSDs) were less than 5.0 %. Conclusion: The method is simple, safe, rapid, accurate and accurate. It is suitable for the determination of trace cadmium in rice.