Application of Laser Ablation-ICPMS to the Spatially Resolved Micro-Analysis of Biological Tissue

Laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) has been applied as a method to determine elemental distribution in biological tissue specimens, providing spatial resolution down to 30 μm with the use of an infrared laser beam. Instrument operating parameters such as the laser energy and “dry plasma” tuning have been optimized to provide the high sensitivity and stability required for this type of analysis. In this work, “natural” internal standards (e.g., calcium and magnesium) have been investigated in an effort to establish and minimize the influence of signal variation associated with the instrumentation and the density of the samples themselves. Specimens studied include fish scales (for “elemental tagging”), rat kidney cross sections, and pig femur (to examine variation in the chemistry of the blood/bone interface).