A Review on Research and Application Progress of LA-ICP-MS Imaging Technology in Geological Science

Laser Ablation-Inductively coupled plasma-mass spectrometry (LA-ICP-MS) imaging is a micro-area element analysis technology developed in the past two decades, and its application has become increasingly widespread. Web of Science search shows that more than 970 relevant papers have been published in this field since 2003, and the number is increasing year by year, especially in the field of geoscience. The technology can accurately present the spatial distribution characteristics of elements in minerals, breaking through the limitations of traditional whole-rock analysis and in-situ spot analysis, which cannot reflect the micro-distribution differences of elements. Thereby, LA-ICP-MS can provide a key microscopic basis for revealing complex geological processes such as rock genesis and mineralization, and has become an important tool in geological research. Till now, LA-ICP-MS imaging has achieved a spatial resolution of 1–10 μm and a detection limit of sub-μg/g, and can simultaneously obtain spatial distribution information of more than 40 elements in one experiment. However, this technology still faces many technical difficulties in practical application, including the constraints of signal transmission and detection efficiency of instrument equipment, the interference of matrix effect in data correction, the impact of surface contamination on analysis results, and the detection limit and data uncertainty. Meanwhile, the efficiency and accuracy of data processing have also become key constraints for technology promotion. This paper systematically reviews the development history and core parameters of LA-ICP-MS imaging technology, focuses on the instrument optimization direction of high-speed and high-resolution imaging (LA system, ICP-MS system and related auxiliary strategies), the functional characteristics and application differences of mainstream data processing software, sorts out the experimental parameter optimization methods and data correction technologies, and summarizes the application achievements and analysis ideas of this technology in geological fields such as deposit geology, magmatic rock research and geochronology combined with typical cases. The study holds that the iterative upgrading of instrument equipment, the refined regulation of experimental parameters, the innovation and improvement of data correction methods, and the functional expansion of the domestic open-source software LIMS2.0 are the core directions to solve the existing problems of LA-ICP-MS imaging technology and improve the analysis performance. The integration of this technology with other analytical technologies such as SEM, TEM and SR-XRF, as well as the in-depth application of big data analysis methods, can give full play to its advantages in micro-area element analysis and explore more abundant geological information. In the future, LA-ICP-MS imaging technology will play a more important role in the research of ore mineralization, magmatic evolution process, etc., and provide more comprehensive and accurate microcosmic data support for geological scientific research.