LC-LTQ-Orbitrap analysis on chemical constituents in Scrophulariae Radix extract and their metabolites in rat plasma Rapid identification of chemical composition in safflower with UHPLC-LTQ-Orbitrap Rapid characterization of chemical constituents and rats metabolites of Kudiezi injection by UHPLC-LTQ-Orbitrap Comparative metabolism of three amide alkaloids from Piper longum in five different species of liver microsomes Identification of alkaloids and flavonoids in all parts of Fritillaria thunbergii using LC-LTQ-Orbitrap MSn