Global characterization of neutral saccharides in crude and processed Radix Rehmanniae by hydrophilic interaction liquid chromatography tandem electrospray ionization time-of-flight mass spectrometry

The combined use of the state-of-the-art hybrid mass spectrometer (MS) together with high efficient liquid chromatography may prove to be a useful tool for neutral saccharide analysis. In the present work, we used hydrophilic interaction liquid chromatography (HILIC) to separate selected saccharides (fructose, glucose, galactose, sucrose, melibiose, raffinose, manninotriose, stachyose and verbascose). Influences of the column type, additive type, temperature, pH and other separation factors on analyte retention were evaluated. The new method did not require reduction, derivatization or postcolumn addition of reagents, which are commonly used in conventional saccharide analysis. Our results demonstrate the potential of HILIC-MS for sensitive and robust determination of saccharides in crude and processed Radix Rehmanniae, and may promote new perspectives in the research of other medicinal herbs.