A high throughput mass spectrometry screening analysis based on two-dimensional carbon microfiber fractionation system

Compounds identification and quantification in complex samples are still a great challenge1,2, because real matrices are generally constituted by an impressive number of substances, which shows great differences in physical and chemical properties, requiring then complex pretreatment, separation and analysis procedures3. In particular, polarity plays a great role in this perspective, making their simultaneous detection and quantification very demanding. Another critical issue that should be addressed is the great difference in the substance content (from mg g−1 to ng g−1), that can lead to mask trace compounds or to saturate the limited capacity of the separation columns: most of them remain unknown or not revealed4. A quite interesting case-of-study in this field is the analysis of medicinal plant extracts. Their composition can provide very important information in metabolomics studies, in the comprehension of the synergistic effects of major and minor components for the plant resources exploitation and for the knowledge of therapeutic mechanisms1,4. The high complexity of these extracts, containing both polar, medium polar and non-polar substances lead to very complex, tedious and time-consuming analytical procedures for their analyses. One possible solution to overtaking all these drawbacks can rely on a new analytical approach that gathers a pretreatment that split molecules with different polarities in distinct fractions with direct MS analyses5. Our research has been focused then toward the realization of a system that could allow this separation in a fast, reliable and inexpensive way. A novel high-throughput, solvent saving and versatile integrated two-dimensional microscale carbon fiber/active carbon fiber system (2DμCFs), that allows a simply and rapid separation of compounds in low-polar, medium-polar and high-polar fractions, has been coupled with ambient ionization-mass spectrometry (ESI-Q-TOF-MS and ESI-QqQ-MS) for screening and quantitative analyses of real samples. 2DμCFs led to a substantial interference reduction and minimization of ionization suppression effects, thus increasing the sensitivity and the screening capabilities of the subsequent MS analysis. The method has been applied to the analysis of Schisandra Chinensis extracts, obtaining with a single injection, a simultaneous determination of 33 compounds presenting different polarities, such as organic acids, lignans, and flavonoids in less than 7 min, at low pressures and using small solvent amounts. The method was also validated using 10