I would like to thank Aiping Zhu, Tian-Sheng Lu, and Shuyu Hou from Medpace Bioanalytical Laboratories, for sharing their poster from ASMS 2024. "A Simple and Sensitive LC-MS/MS Method for Quantification of 7α-hydroxy-4-cholesten-3-one (C4) in Human Serum." I found the application particularly interesting as it shows how Pentafluorophenyl (PFP) HPLC...