激光溅射电离飞行时间质谱用于矿样分析的研究及技术比较

将自行研制的激光溅射电离飞行时间质谱仪（LAI-TOFMS）用于辉绿岩（GBW07123）、石榴石和硅化木3种矿物样品的直接分析，初步讨论了元素含量和元素相对含量的计算方法，计算过程中选Mn作参考元素，并将LAI-TOFMS与电感耦合等离子体质谱（ICP-MS）、X射线荧光光谱（XRF）在样品分析过程和分析结果方面进行比较。LAI-TOFMS中，元素含量是通过相对灵敏系数（RSC）和Mn的含量计算得到，元素的相对含量与元素的相对原子质量及其质谱峰的强度有关；对于ICP-MS和XRF，元素的相对含量是待测元素和Mn含量的比值。初步研究表明：LAI-TOFMS, ICP-MS和XRF 3种分析方法测得的元素含量和元素相对含量结果相对符合较好。此外，由于具有样品前处理简单、几乎不污染样品、样品消耗量少等优点，LAI-TOFMS能够提高矿物样品的分析检测效率。

The Analysis of Ores by Laser Ablation and Ionization Time-of-Flight Mass Spectrometer and Technique Comparison

The direct analysis of GBW07123, garnet and petrified wood were investigated using the homemade laser ablation and ionization time-of-flight mass spectrometer (LAI-TOFMS). Samples were analyzed in pressed pellet forms. Parametric studies were conducted on the mass spectrometer with respect to laser power density, pressure of the buffer gas and repelling modes of the pulse. The tentative methods used to determine elemental concentration and relative elemental concentration of samples were also discussed. In the research, Mn was chosen as the referenced element. In LAI-TOFMS, elemental concentration was calculated by RSCs (relative sensitivity coefficient) and the concentration of Mn, while relative elemental concentration was related to the mass of the measured element and its intensity in the spectrum. In ICP-MS and XRF, relative elemental concentration was the ratio of concentration of measured elements to that of Mn. Analytical process and results of LAI-TOFMS, ICP-MS and XRF were compared. The results presented by LAI-TOFMS are in relatively good agreement with that obtained from ICP-MS and XRF. Moreover, LAI-TOFMS allows for rapid elemental analysis due to its simple sample preparation, almost no contamination to sample and little sample consumption. Ultimately, LAI-TOFMS offers the capability of semi quantitative mineral direct analysis.