It answers: within a single herb, in which tissue, which cell population, which abnormal structure does a certain active ingredient enrich? For example, the 'Zhusha spot' of Baizhu is a macroscopic feature, but what is its chemical nature and which ingredients aggregate to form it cannot be answered by homogenate quantification. A study published by Neo-Source with the China Academy of Chinese Medical Sciences used DESI/PI-MSI to reveal the cause of Zhusha spots in Baizhu (Atractylodes macrocephala), finding that m/z 183.0807 and m/z 301.2164 were strongly correlated with colored structures (SCs), suggesting that accumulation of certain polyynes and sesquiterpenes may be the cause (Molecular Horticulture, 2025).
This is exactly the typical value of micro-localization: directly correlating 'visibly abnormal structures' with 'molecular-level ingredient aggregation'.
TCM ingredients span a wide polarity range and many families. The Neo-Source MSI DPI adopts desorption electrospray ionization combined with photochemical post-ionization, with no polarity bias, and in both positive and negative ion modes can newly detect more than a hundred lipids, terpenoids, flavonoids, amino acids, glycosides, and other secondary metabolites, with overall signal enhanced by 1–3 orders of magnitude, covering the wide polarity range required by TCM micro-localization.
The matrix-free feature is especially critical: herbal sections require no spraying of small-molecule matrix, avoiding matrix-peak interference in the low-mass region and eliminating cumbersome preparation, allowing 'seeing structure + seeing ingredients' to be completed smoothly on the same section.
In imprint imaging of plants and herbal materials, DPI has demonstrated sensitivity for various samples: in Ginkgo, the DESI/PI mode added flavonoids, ginkgolic acid and cardanol, with the mass spectrum showing secretory-cavity distribution; in tea leaf, theanine signal increased by 14.5x and caffeine by 61x, with statistically significant differences between vein and blade regions; in sage, monoterpenes, diterpenes and triterpenes were newly detected. These ingredients are often associated with specific microstructures (secretory cavities, veins, leaf margins).
Methodologically, MSI imprinting can characterize the chemical spatial heterogeneity of different microscopic leaf regions non-destructively and rapidly, providing microscopic evidence for genuine-region herbs, organ-specific use and harvest-time selection.
The 'structure–ingredient' correspondence provided by micro-localization can distinguish herbs of different origins, parts and processing methods, assisting in establishing more refined quality-control and authentication standards. For samples with colored spots, abnormal textures or suspected adulteration, imaging can locate abnormal ingredient enrichment regions, providing a visualized basis for traceability.
Engineered to be compatible with mainstream mass spectrometers from Agilent, AB SCIEX and Thermo, the two Neo-Source imaging sources are matrix-free and measure on demand, allowing pharmaceutical QC and testing staff to get started relatively quickly, pushing micro-localization from a research method to a usable tool.
To obtain detailed specifications, compatible models, or a quotation for the MSI LDPI / DPI full series imaging ion sources, visit the Neo-Source official website, or contact the official team for compatibility advice tailored to your mass spectrometer (Agilent / SCIEX / Thermo and other mainstream MS).