2.4.2. Pretreatment of plasma, urine, and bile samples

The plasma samples collected at different time after the administration were mixed. After the dilution for three times with ultrapure water, an Oasis® HLB column extractor was used for enrichment and purification. The blank plasma sample processing procedure was the same as above.

The urine and bile samples collected at 0–24 h after the administration were mixed. The Oasis® HLB column extractor was used for enrichment and purification. In addition, blank urine and rat bile samples were prepared with the same pretreatment method.

For the above samples, the methanol eluent was collected and dried with nitrogen as the drying medium, followed by redissolution using 70% methanol. The treated samples were sonicated for 10 s, vortexed, and centrifuged at 12,000 r/min for 10 min (D3024, DLAB Scientific Co., Ltd., Beijing, China) to collect the supernatant for further analysis. The sample preparation processes are detailed in Section 3 “Sample preparation” in the Supplementary data.