Laser Ablation - ICP-MS
We have a ESI NWR193UC laser ablation system that can be interfaced to the ICP-MS for direct solid sampling. This is mainly a microanalysis technique but may also be used for bulk sample analysis and also trace element mapping.
We use this system for the in-situ analysis of trace and rare earth elements in minerals such as garnets, cpx, olivine and other silicate and carbonate samples.
Major element composition is used as internal standard for concentration determinations, so most samples are analysed first by the electron probe.
Whenever possible, sections of samples should be prepared 100 micron thick compared to normal thin sections which may only be 30 micron. The size of the glass slide should be 46-48mm long x 25-30 mm width and also conveniently fits the sample holder for the electron probe. Separated grains may be mounted and polished in an epoxy resin block 25 mm in diameter.
Any graphite coating (for probe analysis) should be removed prior to ICP-MS analysis by gentle polishing with a fine diamond paste, rinsed clean and dried.
Finding features to analyse (on some samples) by LA-ICP-MS can be time-consuming. Users are encouraged to bring along printouts of sample 'maps'. Small marks can also be made on the edges of the slide to help locate small features. The microscope on the laser is not equivalent to dedicated petrological microscopes.
For additional information, click here.