Chiral probe labeling techniques in liquid chromatography separation: Advances in chiral metabolomics analysis

The separation and quantitative analysis of chiral compounds are critical for ensuring the safe use of chiral drugs and understanding the functional roles of small-molecule chiral compounds in biological systems. Chromatography-mass spectrometry (MS)-based techniques, especially direct separation and probe labeling methods, are essential for chiral separation. Unlike direct separation methods, the probe labeling technique involves converting chiral analytes into diastereomers via chemical derivatization. This approach not only improves separation efficiency and detection sensitivity in reversed-phase chromatography but also enables the simultaneous trace-level analysis of multiple chiral compounds in complex biological matrices. This review provides a comprehensive overview of recent advancements in chiral compound separation using probe labeling methods. Chiral probes are systematically categorized based on their reactive functional groups, with a thorough analysis of their applicability across various scenarios and the limitations of current probes. Additionally, strategies for targeted absolute quantification, relative quantification, and non-targeted analysis of chiral compounds are discussed, highlighting the potential of probe labeling in metabolic profiling and biomarker discovery. In conclusion, this review offers a systematic examination of the key technologies involved in probe labeling for chiral compound separation and quantification. It provides valuable insights into efficient chiral biomarker screening and offers strong technical support for drug quality assessment, research, and development. These advancements have significant scientific and practical implications for the advancement of chiral chemistry.