微波消解-碰撞反应池技术电感耦合等离子体质谱法测定粮食中硒的方法研究

Research on determination of selenium in foods by inductively coupled plasma mass spectrometry based on collided reaction cell technology with microwave digestion

目的建立测定粮食硒的微波消解-碰撞反应池技术电感耦合等离子体质谱法,为准确定量粮食含硒量提供新的可靠方法。方法样品经微波消化后直接采用碰撞反应池电感技术结合耦合等离子体质谱仪(ICP-MS)进行测定。用锆(90Zr)内标校正基体干扰和漂移,用高性能Xs接口降低非质谱干扰,用碰撞反应池技术(CRCT模式)消除质谱干扰。结果方法的标准曲线最佳线性范围为0～100μg/L,相关系数为0.999 8。方法检出限0.002 5 mg/kg,最低检出浓度为0.007 5 mg/kg,相对标准偏差1.6%～4.5%,回收率为94.0%～104.0%。对3个标准参考物质小麦粉(GBW08503)、大米(GBW10010)、小麦(GBW10011)的测定值(0.059、0.073、0.048 mg/kg)均在标准值(0.049±0.014)mg/kg、(0.061±0.015)mg/kg、(0.053±0.007)mg/kg范围内,分析结果令人满意。结论本法不仅检出限低、操作简便、快速,同时又有良好的重复性、较高的回收率,对样品的测定结果与仲裁法(氢化物原子荧光法)一致,能用于粮食硒的准确测定。

Objective To establish a new and reliable method for the accurate determination of selenium （Se） contents in foods by inductively coupled plasma mass spectrometry based on collided reaction cell technology with microwave digestion. Methods After microwave digestion, samples were directly determined by inductively coupled plasma mass spectrometry based on collided reaction cell technology. Internal standard element of zirconium （^90Zr） was used to correct matrix interferences and signal drifting, high-performance Xs （X sensitive ） interface was used to reduce non-mass spectrum interferences, and the collided reaction cell technology （CRCT mode） was used to eliminate mass spectrum interferences. Results The optimal linear range of the standard curve was 0 - 100 μg/L with a correlation coefficient of 0. 999 8. The detection limit, the lowest quantitative limit, the relative standard deviation and the recovery rate wcrc 0. 002 5 mg/kg, 0. 007 5 mg/kg, 1.6% - 4.5% and 94.0% - 104. 0% , respectively. The results on three reference material, Wheat flour （GBW08503） , Rice （GBW10010） and Wheat （ GBW10011 ） , were 0. 059 mg/kg, 0. 073 mg/kg, 0.048 mg/kg, met the scope of the standard value （0.049 ±0.014） mg/kg, （0.061 ±0.015） mg/kg and （0.053 ± 0. 007） mg/kg, respectively. The results were satisfactory. Conclusion The results showed that the method had many advantages such as sensitive, simple, rapid, accurate, good repeatability and recovery rate. It was consistent with arbitral method （HG-AFS） , thus available for the accurate quantitative analysis of selenium in foods.