Depth-resolved analysis in multi-layered glass and metal materials using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS)

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was examined as a tool for depth analysis in glass and metal samples. Layered experimental samples of known thickness were ablated using 266 nm and 193 nm laser systems. The controlling parameters were power density of the laser, crater geometry and gas medium. Layers at depths of up to 200 µm could be identified, but accurate determination of the composition of the underlying layer in the material was strongly dependent on the parameters used. Continued ablation of material from the upper layer took place for up to 200 laser pulses after penetrating the underlying layer. Depth resolution was limited by the mixing of material between shallow and deep levels in the ablation crater. Optimum conditions were determined for reducing the mixing effects and for accurate compositional analysis.