Grant: Research Tools and Instruments - Category 1 (<$150,000)

We request funds to purchase equipment necessary for developing techniques to chemically analyze heterogeneous geological and biological materials in three dimensions (3D) by laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS). The equipment includes (1) specialized grinders and polishers to prepare specimens to a high degree of surface reproducibility down to the micron-scale, and (2) a second sample cell for the ICP-MS to avoid cross-contamination from dissimilar materials in the laser ablation system. The newly installed LA-ICP-MS system at the Pacific Centre for Isotopic and Geochemical Research (PCIGR) at the University of British Columbia can analyze trace and ultra-trace element concentrations of minerals and biological materials. The ablation cell supplied with this instrument is capable of high-spatial resolution via the delivery of a narrow laser beam and rapid washout of the laser ablation cell. This instrument can produce two-dimensional (2D) compositional maps of low abundance trace elements by rastering the laser beam across the polished specimen, which an electron microprobe cannot practically accomplish due to its higher detection limits. Most geological and biological samples are heterogeneous in texture and composition. Two-dimensional maps of their chemical composition can reveal complex spatial variations in chemistry imparted during their growth, which provides important clues to how they formed. Interpretation of these data can be inhibited by uncertainty in the third dimension. We propose that sequential 2D laser ablation mapping can be used to reveal the 3D distribution of trace elements within these materials by producing a depth series of two-dimensional LA-ICP-MS maps, each measured after an increment of grinding and polishing. An additional laser ablation cell is required to allow for the analysis of both biological and mineral matrices that may interfere with one another. Acquisition of the requested equipment will allow a large and diverse group of scientists and associated highly-qualified personnel (HQP) to conduct scientific studies on the frontier of applications of LA-ICP-MS technology in the earth, biological and environmental sciences.