High-throughput UHPLC–MS/MS method for 15 protein-bound uremic toxins in human serum

> 0.99), with lower limits of quantification (LLOQ) of 10-20 ng/mL. The limits of detection (LOD) ranged from 5 to 10 ng/mL, and the precision expressed as relative standard deviation (RSD) was below 15%. Application to serum samples from 40 uremic patients and 20 healthy controls revealed significantly elevated levels of 10 PBUTs, with p-cresyl sulfate (PCS) concentrations approximately 400-fold higher in patients. Five PBUTs were undetectable in healthy individuals. This study provides a reliable and accurate method for PBUTs quantification, offering valuable insights into the critical role of PBUTs in the pathogenesis of CKD-MBD, and advancing PBUT-related metabolomic research.