A Dynamic Multiple Reaction Monitoring Method for the Multiple Components Quantification of Complex Traditional Chinese Medicine Preparations: Niuhuang Shangqing Pill As an Example

It is a challenging task to simultaneously and quantitatively analyze multiple components in DFF [Da-Fu-Fang, namely, complex traditional Chinese medicine (TCM) preparations containing more than ten TCMs] due to their numerous and extreme complex chemical compositions possessing a wide variety of chemical and physical features, and their very low content. Rather than using a conventional mass spectrometry (MS) method with multiple reaction monitoring (MRM), in the current study, this challenge was addressed by using dynamic multiple reaction monitoring (DMRM). Using a DFF, Niuhuang Shangqing pill, which is composed of 19 TCMs, as a model, a rapid (one run in 20min), sensitive [lower limit of detection (LOD) and limit of quantitation (LOQ) were achieved comparable with MRM] and accessible (a standard HPLC/MS/MS instrumentation was employed) MS method was successfully developed for the simultaneous quantification of 41 bioactive components which represented 15 of the 19 medicinal plants. A comparison of LOD and LOQ using MRM and DMRM was made to quantitatively reveal that the latter demonstrated advantages over the former. Meanwhile, a standard operating procedure concerning the development of a new DMRM method was recommended. The MS data were obtained in the positive ion mode with electrospray ionization as the ion source, acetonitrile and water as mobile phase and a Kinetex C18 core-shell column (100mm×2.10mm, 2.6μm, Phenomenex Inc.) as the analytical column. This method was then applied to 32 batches of samples. It transpired, through principal component analysis and orthogonal partial least squares discriminant analysis, that the consistency of the products was relatively good within one company, but poor among different companies among the 32 samples; one failed to qualify in terms of the Chinese Pharmacopeia. This work illustrated that the proposed DMRM method was particularly suitable for quantifying the trace components in DFF and capable of ensuring the quality of DFF.