ICP-MS法同时检测谷物中16种稀土元素

Determination of 16 Rare Earth Elements in Cereals by Inductively Coupled Plasma Mass Spectrometry

采用密闭高压消解技术,建立电感耦合等离子体质谱法同时测定谷物中16种稀土元素的方法。完善样品前处理条件并优化仪器工作参数,选取103Rh为内标元素消除非质谱干扰,氨气为动态反应气消除质谱干扰。16种稀土元素在测定的范围内线性关系良好（R〉0.999）,检出限为0.1-33.3 ng/L,回收率为81.8%-108.3%,相对标准偏差（RSD）〈6.0%。方法经国家一级标准物质验证,结果与标示值相符。试验表明,方法精密度好,准确度高,适用于谷物中稀土元素的快速测定。

A novel method was developed for the determination of 16 rare earth elements in cereals by inductively coupled plasma mass spectrometry （ICP-MS） with sealed high pressure digestion for sample preparation. The preparation conditions were improved and the instrument operating parameters were optimized. ^103Rh was selected as the internal standard element to overcome non-spectroscopic interference and ammonia was used as dynamic reaction gas to eliminate mass spectroscopic interference. Satisfactory linearity of standard curve was obtained with elemental correlation coefficient over 0.999, the detection limits were in the range of 0.1-33.3 ng/L, the recovery of samples was in the range of 81.8%-108.3%, and the relative standard deviation （RSD） was less than 6.0%. The method was tested using national standard substance and the results were in good agreement with the recommended values. The results showed this method was suitable for rapid determination of rare earth elements in cereals with good precision and high accuracy.