分析元素在ICP-MS取样锥口的空间分布

Spatial Investigation of Analytes at the Sampling Cone of an ICP-MS

为提高电感耦合等离子体质谱仪(ICP-MS)的检测灵敏度,需保证分析离子在ICP与质谱仪间的传递效率。本研究利用激光诱导荧光技术,以钡元素为分析粒子,在不同ICP功率、雾化气流速的条件下,对分析元素在ICP-MS取样锥前端的空间分布及等离子体温度的变化进行研究。结果表明,ICP功率、雾化气流速对被分析物质在等离子体内的原子化及电离过程有很大的影响,但增加ICP功率并不一定能提高被分析粒子到达ICP-MS取样锥口的数量。该结果可为提高ICP-MS仪器性能及改进设计方法提供理论参考。

To improve the sensitivity of an inductively coupled plasma mass spectrometer（ICP-MS）,the analytes ions must be transmitted from the plasma through the interfacial region as efficient as possible.Understanding transport behaviors of analytes from the plasma through the sampling cone require knowledge of analytes spatial distributions at the tip of the sampling cone.Relying on laser induced fluorescence technique,the temperature variations of the plasma and spatial distribution of barium at the tip of the sampling cone of an ICP under a seris of experimental conditions were investigated.The result shows that ICP incident power and nebulizer flow have significant impact on the atomization and ionization of analytes.However,higher ICP incident power does not mean higher efficiency of analytes reaching the sampling cone.The results can provide some guides to design improvement of a commercial ICP-MS.