A New Mapping Protocol for Laser Ablation (with Fast‐Funnel ) Coupled to a Time‐of‐Flight Mass Spectrometer ( LA‐FF‐ICP‐ToF‐MS ) for the Rapid, Simultaneous Quantification of Multiple Minerals

Although in situ analysis by LA-ICP-MS is considered a rapid technique with minimal sample preparation and data reduction, mapping areas of millimetres in size using a small beam (< 15 mu m) can be time consuming (several hours) when a quadrupole ICP-MS is used. In addition, fully quantitative imaging using internal standardisation by LA-ICP-MS is challenging in samples with more than one mineral phase present due to varying ablation rates. A new protocol for the quantification of multiple coexisting phases, mapped at a rate of about 12 mm(2) h(-1) and a resolution of 12 mu m x 12 mu m per pixel, is presented. The protocol allows mapping of most atomic masses, ranging from Na-23 to U-238, using a time-of-flight mass spectrometer (ICP-ToF-MS, TOFWERK) connected to a 193 nm excimer laser. A fast-funnel device was successfully used to increase the aerosol transport speed, reducing the time usually required for mapping by a factor of about ten compared with a quadrupole ICP-MS. The lower limits of detection for mid and heavy masses are in the range 0.1-10 mu g g(-1), allowing determination of trace to ultra-trace elements. The presented protocol is intended to be a routine analytical tool that can provide greater access to the spatial distribution of major and trace elements in geological materials.