Simultaneous Determination of 15 Flavonoids in Scutellaria barbata-Hedyotis diffusa Herb Pair by HPLC Q-TOF MS

Background: The Scutellaria barbata-Hedyotis diffusa herb pair has appeared in classical prescriptions and has usually been used for the treatment of cancer and inflammatory conditions. Objective: For quality control of this herb pair, a rapid and reliable HPLC-quadrupole-time-of-flight(Q-TOF)-MS method was used for the simultaneous determination of alpinetin, apigenin-7-O-β-D-glucopyranoside, scutellarein, apigenin, quercetin-3-O-β-D-glucopyranoside, wogonoside, quercetin, amentoflavone, wogonin, chrysin, luteolin, rutin, naringenin, baicalein, and baicalin in the S. barbata-H. diffusa herb pair. Methods: LC-MS analysis was performed on a Shimadzu HPLC 20ADXR LC system in-line with an AB-SCIEX 5600 Triple TOF mass spectrometer. Results: The calibration curves showed good linearity in a relatively wide concentration range (r >0.996). The LOD and LOQ were less than 20 and 68 ng/mL, respectively. The relative standard deviation (RSD) values of intraday and inter-day precision were <3.31% for all the analytes. The recoveries of the method were in the range of 94.6-106.0%, with RSD <4.72%. The RSD values of peak areas in the stability study were not more than 4.28% for all analytes within 2 days. These results revealed that the method exhibited good sensitivity, precision, accuracy, and stability. Conclusions: This method could be applied to the quantitative determination of 15 flavonoids in the S. barbata - H. diffusa herb pair. Highlights: (1) The established method of HPLC-Q-TOF-MS is simple, fast, sensitive, and reliable. (2) 15 Flavonoids in the S. barbata-H. diffusa herb pair were simultaneous determined.