Abstract:
The carbon fiber ionization mass spectrometry (CFI-MS) method was used to quickly and directly analyse volatile components in traditional Chinese medicine (TCM) without pretreatment. Three key factors affecting the signal intensity of CFI-MS were optimized, which was voltage, horizontal distance between carbon fiber tip and mass spectrometer entrance, and vertical distance between TCM sample and carbon fiber tip. Taking cinnamaldehyde as an example, the signal intensity changes of CFIMS on samples with different concentrations were investigated. And then the optimized CFI-MS was used to quickly and directly analyse TCMs without any pre-treatment, that was Ramulus Cinnamomi, Angelica sinensis, Ligusticum chuanxiong, Patchouli oil, Fufangchuanxiong capsules and Siwu granules, as the result various components were successfully characterized, such as hydrocarbons, terpenes, aldehydes, ketones, phenols, esters, and steroids. In addition, the optimized CFIMS was used to quickly and directly analyse the Ramulus Cinnamomi and tangerine peel of different freshness, and the freshness could be identified from the differences in mass spectra. The method is simple, reliable and rapid analysis, which can perform rapid and direct system characterization research on volatile components in TCM. The use of CFI-MS provides scientific theoretical basis for the research on the substance base and quality control of TCM. In addition, the residual compounds on the carbon fiber can be quickly removed by flame combustion. As a result, there is no cross-contamination, so CFI-MS shows the potential for high-throughput analysis. Compared with other AI-MS, CFI-MS device is simple, easy to operate, less adjustment parameters, rapid and efficient, time-saving and labor-saving in direct analysis.