Abstract:
Traditional Chinese medicines (TCMs) have played a key role to maintain health for Chinese people for thousands of years, and the chemical compositions should be responsible for the pronounced therapeutical benefits. It is thereby of great importance to analyze the chemical compositions of TCMs. Liquid chromatography coupled with tandem mass spectrometry is widely used for the chemical profiling of TCMs. However, chromatographic separations have been complained as a time-consuming course, thus dampening high-throughput measurement. Fortunately, attributing to the assistance of gas phase fractionation technique, MS/MSALL owns a unique ability namely mass spectrometric separation via enabling MS1 ion cohort sequentially entering the collision cell and acquiring MS2 spectrum for each 1 u mass bin. Lycii Fructus is one of the most famous edible herbal medicines and featured with the tonic benefits towards liver, kidney, and eye as well. It is necessary to pursue a rapid method to characterize the chemical profiles. Herein, Lycii Fructus was employed as a representative case to illustrate and validate the applicability of direct injection coupled tandem mass spectrometry full scan (DI-MS/MSALL) towards rapid chemome characterization of TCM. First, Lycii Fructus extract was directly imported into electrospray ionization source of quadrupole time-of-flight mass spectrometer with an infusion pump at a flow rate of 10 μL/min. Then, MS/MSALL was programmed for multi-stage spectral measurements under positive and negative ionization modes. MS1 spectrum was recorded in the range of m/z 50-1 000, and MS2 spectrum was acquired for each mass window with 1 u width from m/z 50 to m/z 1 000. After assigning each MS2 spectra to its precursor ion, the MS1-MS2 dataset was constructed, and extensive attention was subsequently paid onto MS/MS spectral interpretation. Following database retrieval and reference data, a total of 38 components were tentatively identified from Lycii Fructus extract, including one amino acid, nineteen organic acids, two glycolipids, six phenylpropanoids, one flavonoid, six alkaloids as well as three amides. Above all, DI-MS/MSALL is an eligible analytical tool for rapid and in-depth chemome characterization of traditional Chinese medicine as well as some other complicated matrices.