Cutting‐edge LC–MS/MS applications in clinical mass spectrometry: Focusing on analysis of drugs and metabolites

Abstract In recent years, liquid chromatography with tandem mass spectrometry (LC–MS/MS) has become a fundamental technology in clinical practice. In Japan, the LC–MS/MS system is used in many large hospitals. It has become popular among pharmacists and laboratory technicians. LC–MS/MS has some advantages in terms of accuracy, speed, and comprehensiveness compared to conventional automated chemical testing equipment. However, LC–MS/MS is by no means a universal method, and it is necessary to understand its characteristics before using it. In the field of therapeutic drug monitoring (TDM), there is an issue with linearity in comprehensive measurement; however, ion‐abundance adjustment methods, such as in‐source collision‐induced dissociation, have been proposed as a solution to this problem. The development of a biomarker analysis includes search, identification, and quantification, and it is necessary to select an appropriate mass spectrometric method for each step. In this paper, we review cutting‐edge technologies that can expand the performance of LC–MS/MS in the clinical field and consider current issues and future prospects.