This study aimed to establish a rapid analytical method for the determination of 69 pesticide residues in Platycodonis Radix using GC-MS/MS and UHPLC-MS/MS, as well as carry out a dietary risk assessment on 42 batches of Platycodonis Radix samples collected from different geographical origins. Samples were prepared using the QuEChERS method, followed by high-speed centrifugation and membrane filtration, and the target pesticides were analyzed in selected reaction monitoring (SRM) mode via GC-MS/MS and in multiple reaction monitoring (MRM) mode via UHPLC-MS/MS. Among the 42 tested batches of Platycodonis Radix samples, 3 out of 27 pesticide compounds were detected via GC-MS/MS screening, while only 1 pesticide compound was positive from the 42 compounds determined via UHPLC-MS/MS, and the risk assessment results demonstrated that both chronic and acute dietary exposure risks of all detected pesticides were considerably lower than 1.

Isodonis Excisoidis Herba (IEH) is a newly discovered herbal medicine used to treat esophageal cancer, chronic pharyngitis, and hepatitis, and ent-kaurane diterpenoids are its main active components. However, systematic studies on the chemical profile of ent-kaurane diterpenoids are lacking. In this study, UHPLC-LTQ-Orbitrap-MS was performed to investigate the fragmentation behaviors of three different types of ent-kaurane diterpenoids from IEH. Bridgehead-unsubstituted 7,20-epoxy-ent-kaurane diterpenoids yielded ions with typical losses of R₇H, R₁H, R₁₄H, CH₂O, CO, and R₆H. The [M + NH₄ − NH₃ − R₂₀]⁺ precursor ions at 331.1895 and the characteristic ions at m/z 313.1792, 295.1686, 285.1842, 277.1581, 267.1737, and 249.1632 were the most possible fragmentation pathways for bridgehead-substituted 7,20-epoxy-ent-kaurane diterpenoids. Fragmentation with the successive loss of multiple 18, 42, or 60 Da occurring in the OH groups and OAc groups is characteristic of 7,20-non-epoxy-kaurane diterpenoids. Using accurate mass measurements for each precursor ion and the subsequent fragmented ions, a total of 94 ent-kaurane diterpenoids were identified or tentatively characterized in IEH, including 48 potentially new ent-kaurane diterpenoids.