Mass spectrometry imaging analysis of traditional Chinese medicine by laser ablation-dielectric barrier discharge ionization.

With its exceptional resolving power and sensitivity, mass spectrometry (MS) is widely regarded as the most informative analytical technique for the qualification and quantification of metabolites in plant sciences. However, conventional MS approaches lack spatial information, which is critical for understanding plant physiological mechanisms. To address this limitation, mass spectrometry imaging (MSI) has emerged as a transformative tool, enabling the visualization of metabolite spatial distribution in complex samples and providing deeper insights into plant metabolic processes. This study introduces a novel MSI platform combining laser ablation (LA) with dielectric barrier discharge ionization (DBDI) to obtain MSI images with 40 µm pixel size for in situ metabolic profiling. The LA-DBDI-MSI platform was applied to analyze a traditional Chinese medicine sample, Scutellaria baicalensis Georgi, revealing the spatial distribution of key bioactive compounds in a single experiment. This cost-effective and flexible system demonstrates significant potential for advancing metabolomics research and the development of traditional medicinal materials.