The analyses of layered structures in banded samples is a challenging and fascinating application of LA-ICP-MS. Typically, the analyst desires to achieve the greatest possible spatial resolution to discerne fine detail in the sample's structure. Reducing the spot size is problematic, as this dramatically reduces the volume of sample sent to the ICP and, depending on the application, may prohibit detection of the structure of interest.
To optimize the ablation of banded samples a rectangular spot can be used, with the short axis aligned in the direction requiring maximum resolution. This provides an ideal compromise between analytical resolution and sample volume. Since few banded samples feature perfectly parallel structures, it is essential to rotate the slit as the sample is scanned beneath the laser.
RESOlution instruments feature an optional rotating slit module that provides this functionality, optimizing the instrument for the analyses of banded samples. The slit size can be adjusted to suit the sample and the GeoStar software provides complete control with a visual preview of the path to be ablated.