A strategy for establishment of practical identification methods for Chinese patent medicine from systematic multi-component characterization to selective ion monitoring of chemical markers: Shuxiong tablet as a case study

Authentication of Chinese patent medicine (CPM) is more challenging than that of a single herbal medicine due to the increasing complexity in the chemical matrix. A strategy from systematic multi-component characterization to selective ion monitoring of chemical markers (SMC-SIM) is presented and applied to authenticate Shuxiong tablet (SXT) as a case study. First, an ultra-performance liquid chromatography/quadrupole time-of-flight-Fast DDA (UPLC/QTOF-Fast DDA) approach was developed to comprehensively profile and characterize multi-components in SXT. Second, chemical markers were established using a home-made SXT sample. The SIM method for detection of these markers was initially established on an advanced QTOF mass spectrometer, and then transferred onto an easily accessible single quadrupole QDa detector. Third, the UPLC/QDa-SIM method was used to authenticate commercial SXT samples. Consequently, 250 compounds were characterized, and 73 of them were identified by comparison with reference standards. Two UPLC-SIM methods enabling the monitoring of eleven chemical markers (including five saponins for Notoginseng Radix et Rhizoma, two quinochalcone C-glycosides and a flavonoid O-glycoside for Carthami Flos, one phenolic acid and two phthalides for Chuanxiong Rhizoma), were developed on QTOF and QDa, respectively. Twelve batches of commercial SXT samples were identified by the UPLC/QDa-SIM method. Despite the lower sensitivity, the QDa-SIM method by simple sample preparation achieved similar authentication results, and was more easily generalized in practice than the QTOF-SIM method. In conclusion, targeted monitoring of multiple chemical markers was proven as feasible in comprehensive identification of CPM, and the SMC-SIM strategy enabled establishment of practical quality control methods for CPM that contains a complex chemical matrix.