Two high-performance liquid chromatographic assays for the determination of free and total silibinin diastereomers in plasma using column switching with electrochemical detection and reversed-phase chromatography with ultraviolet detection - Rickling,B.; Hans,B.; Kramarczyk,R.; Krumbiegel,G.; Weyhenmeyer,R. (J Chromatogr B Biomed Appl, 1995)