Minimizing Matrix Effect by Femtosecond Laser Ablation and Ionization in Elemental Determination

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• 作者：Bochao Zhang ; Miaohong He ; Wei Hang ; Benli Huang
• 刊名：Analytical Chemistry
• 出版年：2013
• 出版时间：May 7, 2013
• 年：2013
• 卷：85
• 期：9
• 页码：4507-4511
• 全文大小：368K
• 年卷期：v.85,no.9(May 7, 2013)
• ISSN：1520-6882

文摘

Matrix effect is unavoidable in direct solid analysis, which usually is a leading cause of the nonstoichiometric effect in quantitative analysis. In this research, experiments were carried out to study the overall characteristics of atomization and ionization in laser鈥搒olid interaction. Both nanosecond (ns) and femtosecond (fs) lasers were applied in a buffer-gas-assisted ionization source coupled with an orthogonal time-of-flight mass spectrometer. Twenty-nine solid standards of ten different matrices, including six metals and four dielectrics, were analyzed. The results indicate that the fs-laser mode offers more stable relative sensitivity coefficients (RSCs) with irradiance higher than 7 脳 10¹³ W路cm^鈥?, which could be more reliable in the determination of element composition of solids. The matrix effect is reduced by half when the fs-laser is employed, owing to the fact that the fs-laser ablation and ionization (fs-LAI) incurs an almost heat-free ablation process and creates a dense plasma for the stable ionization.