Simultaneous determination of multiple compounds of Da-Huang-Xiao-Shi decoction in rat plasma by LC-MS/MS and its application in a pharmacokinetic study.

•A novel LC–MS/MS method for bioanalysis of Da-Huang-Xiao-Shi decoction (DHXSD).•Multiple compounds of DHXSD were simultaneously monitored in plasma.•Monitoring 13 prototypes and their glucuronide/sulfate metabolites.•Challenge of structual diversity and various linear ranges of compounds was overcome.•The pharmacokinetic characteristics of DHXSD were studied for the first time