Rapid assessment of the quality of Qingkailing products using wooden-tip electrospray ionization mass spectrometry combined with multivariate statistical analysis

Abstract

This study demonstrates the application of wooden-tip electrospray ionization mass spectrometry (wooden-tip ESI-MS) combined with multivariate statistical analysis for achieving a rapid quality assessment of Qingkailing products, which is a famous combinatorial herbal formula registered by Chinese Pharmacopoeia. By utilizing sharp wooden tips to load samples and induce ESI for mass spectrometric analysis, various ingredients with different chemical structures present in Qingkailing products were detected simultaneously without any sample pretreatment with an analysis speed of approximately 1 min per sample. There were 26 characteristic peaks in the negative ion wooden-tip ESI-MS fingerprint of Qingkailing, which were successfully identified by the collision-induced dissociation experiments. The developed method was applied to evaluate the quality and trace the origins of 16 batches of Qingkailing oral liquid and 9 batches of Qingkailing granule samples. By using multivariate statistical analysis on the obtained MS fingerprints, different Qingkailing samples were successfully differentiated, and their quality stability and consistency were also easily assessed. In addition, the qualified and damaged samples were distinguished unambiguously. Our results demonstrated that the combined application of wooden-tip ESI-MS and multivariate statistical analysis could be a rapid strategy for pharmaceutical analysis with promising prospects for tracing the origins and assessing the quality of herbal medicines and related products.