建立了微波消解-ICP-MS测定水稻植株中钒、钴、镍、铜、锶、钼、镉、铊和铅9种微量重金属元素的方法。探讨了微波消解条件、ICP-MS仪器工作条件及影响测定的因素。结果表明,选铟和钪作为内标元素可有效地对分析信号的漂移及基体效应有很好的补偿作用,引入动态反应气NH3可有效地消除多原子离子的干扰。在优化的实验条件下,该方法对各元素的检出限为0.008~0.03μg/L,相对标准偏差为0.8~3.2%,加标回收率为94.2~103.7%。对标准混合液样品的分析结果与所给的标准值吻合,方法准确可靠,用于水稻植株中微量重金属元素的分析,有助于预警稻米安全性,且能达到良好效果。
A method is founded for determination of trace heavy metal elements (V, Co, Ni, Cu, Sr, Mo, Cd, Pb, T1) in rice by ICP-MS with microwave digestion in this paper. The interference effects of method, the conditions for microwave digestion and inductively coupled plasma mass spectrometry (ICP-MS) were investigated. It is indicated that the internal standards of Indium and Scandium were selected can availably compensate the drift of analytical signals and matrix effect; and that dynamic gas of ammonia can efficiently eliminate the interferences of polyatomic ions. Under the optimum experimental conditions, the detection limits for each element are in range of 0.008-0.03μtg/L and the relatively standard deviations of 0.8-3.2% with the rate of recoveries between 94.2% and 103.7%. The analytical of results of calibration solutions demonstrate the applicability of the proposed method, and it is used to determination of trace heavy metal elements in rice plant samples, contribute to early warning security for rice with satisfactory result.