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建立了微波消解-电感耦合等离子体质谱法测定大米中痕量Se和Sr杂质含量的方法。大米样品在微波辅助下用浓硝酸直接溶解,加热蒸酸后样品溶液用电感耦合等离子体质谱测定。Se元素的方法检出限为3.40 ng/g,Sr元素的检出限为0.10 ng/g。用所建立的方法,分别完成了对精米及糙米中Se和Sr的测定,并进行了加标回收试验,加标回收率为95%～105%。样品平行7次测定的相对标准偏差小于5%。测定大米粉标准物质中的硒含量,结果在允许差范围内。
A method for the determination of trace Se and Sr in rice by microwave digestion-inductively coupled plasma mass spectrometry was established. The sample of rice was directly dissolved with concentrated nitric acid with the help of microwave. The sample solution was heated with distilled water and determined by inductively coupled plasma mass spectrometry. The detection limit of Se element is 3.40 ng / g, and the detection limit of Sr element is 0.10 ng / g. With the established method, the determination of Se and Sr in polished rice and unpolished rice were completed respectively, and the spiked recovery tests were carried out. The recoveries were 95% -105%. The relative standard deviation of seven parallel determinations was less than 5%. Determination of rice flour standard content of selenium, the result is within the allowable difference.