Campbell A J, Humayun M
Department of the Geophysical Sciences, The University of Chicago, Chicago, Illinois 60637.
Anal Chem. 1999 Mar 1;71(5):939-46. doi: 10.1021/ac9808425.
A laser ablation microanalysis system has been developed that can analyze trace elements with a sensitivity in the ppb range, using a CETAC LSX-200 laser ablation system with a Finnigan Element. This capability has been applied to a set of iron meteorites to demonstrate the laser microprobe's analytical capability for the determination of platinum group elements (PGEs) with a spatial resolution of ∼20 μm, comparable to that of dynamic secondary ion mass spectrometry (SIMS). The laser is shown to provide an accurate means of solid sampling for magnetic sector inductively coupled plasma mass spectrometry (ICPMS), allowing the determination of bulk metal composition, chemical zoning within the sample, and depth profiling. Recovery of the chemical zoning in taenite lamellae was achieved for Ru, Rh, and Pd, which was not previously possible using SIMS. The methods presented here show that magnetic sector ICPMS can be successfully coupled to a laser ablation system, providing the advantages of higher sensitivity of the sector instrument, low background count rates (<0.1 counts/s), and flat-topped spectral peaks, while minimizing tradeoff against the speed of data acquisition required to handle the transient signals from the laser ablation system.
已经开发出一种激光烧蚀微分析系统，该系统使用配备菲尼根元素（Finnigan Element）的CETAC LSX - 200激光烧蚀系统，能够以皮克/升范围内的灵敏度分析微量元素。此功能已应用于一组铁陨石，以证明激光微探针在测定铂族元素（PGEs）方面的分析能力，其空间分辨率约为20μm，与动态二次离子质谱（SIMS）相当。结果表明，该激光为磁扇形电感耦合等离子体质谱（ICPMS）提供了一种准确的固体采样方法，可用于测定块状金属成分、样品内的化学分区以及深度剖析。对于钌（Ru）、铑（Rh）和钯（Pd），实现了在镍纹石薄片中化学分区的恢复，这在以前使用SIMS时是不可能的。本文介绍的方法表明，磁扇形ICPMS可以成功地与激光烧蚀系统耦合，具有扇形仪器更高的灵敏度、低背景计数率（<0.1计数/秒）和平顶光谱峰等优点，同时将处理激光烧蚀系统瞬态信号所需的数据采集速度的权衡降至最低。
