LA-ICP-MSを用いたU-Pb年代測定における実験計画法による手法開発

Inductively Coupled Plasma Mass Spectrometry (ICP-MS), when combined with laser ablation (LA-ICP-MS), is widely used for precise U-Pb zircon geochronology. While the technique is powerful, reliable age determinations depend on careful optimization of laser and plasma parameters of the instrument. In this study, we used a Sector Field ICP-MS (Thermo Scientific Element 2) coupled to a New Wave UP213 laser to present practical, step-by-step measurement and optimization procedures for geological U-Pb dating. Here, Design of Experiments (DoE)-a statistical approach that evaluates multiple parameters simultaneously and reveals their interactions-was used to efficiently determine optimal analytical conditions with a limited number of experiments. For the first time in LA-ICP-MS research, a DoE framework was applied to systematically optimize instrumental settings. DoE is also compared with conventional manual optimization strategies, providing clear evidence that statistically guided optimization enhances accuracy, reproducibility, and robustness, while reducing operator bias and time required for method development.•The outcome of our method demonstrate that DoE not only identifies the most influential parameters but also accounts for interactions often overlooked during manual refinement. Optimization of U-Pb dating using LA-ICP-MS.•First systematic application of DoE in LA-ICP-MS studies.•Comparative evaluation of manual versus DoE-based optimization.