The application of laser-ablation microprobe; inductively coupled plasma-mass spectrometry (LAM-ICP-MS) to in situ trace-element determinations in minerals
The application of laser-ablation microprobe; inductively coupled plasma-mass spectrometry (LAM-ICP-MS) to in situ trace-element determinations in minerals
The Canadian Mineralogist (December 1992) 30, Part 4: 1049-1064
- apatite
- chemical analysis
- electron probe data
- garnet group
- inductively coupled plasma methods
- laser methods
- mass spectroscopy
- metals
- minerals
- nesosilicates
- orthosilicates
- phosphates
- rare earths
- silicates
- spectroscopy
- titanite
- titanite group
- trace elements
- trace-element analyses
- uranium minerals
- X-ray data
- zircon
- zircon group
- laser ablation microprobe
A laser ablation microprobe (LAM) sample-introduction system designed for in situ microsampling of minerals in petrographic sections has been interfaced with an ICP-MS system. The response of rock-forming minerals to ablation is related to their absorptivity of the 1064 nm wavelength of the Nd:YAG laser beam (a function of the transition elements, especially Fe), and their physical properties, particularly cleavage and tenacity. Minerals with high absorptivity can generally be ablated controllably, but in those with low absorptivity catastrophic ablation may occur at the mineral/glass interface; however, with the exception of such well cleaved minerals as fluorite and calcite, most minerals can be ablated controllably in unsupported polished wafers, grain mounts and polished blocks, where ablation pits with diameters of 20-40 mu m can be achieved routinely. Results for titanite, zircon, apatite, uraninite and garnet separates are reported; routine limits of detection are approximately 0.5 ppm.