Advancements in compound-specific hydrogen stable-isotope analysis of fatty and amino acids

This review explores advancements in compound-specific hydrogen stable isotope ( δ 2 H) analysis (CSIA) of amino and fatty acids from biological samples, highlighting their increased applicability in ecological, environmental, and physiological research. We discuss the current analytical capabilities and limitations of δ 2 H-CSIA, emphasizing important technical challenges associated with hydrogen isotope exchange of samples with ambient moisture and detection limitations posed by the low natural abundance of deuterium. Key developments in gas chromatography-isotope ratio mass spectrometry (GC-IRMS) are detailed, illustrating their role in improving our ability to trace metabolic, ecological and environmental processes. Topics include strategies for addressing the challenges of exchangeable hydrogen for amino acids, recent technological improvements to improve IRMS precision for δ 2 H-CSIA, and the potential for new applications in ecological research, food authenticity, and palaeoecological studies. This review underscores that ongoing progress and improvements in CSIA technology are required for future research to further our understanding of ecological and nutritional dynamics. • Technical challenges due to exchangeable H and low D abundance complicate analysis. • Improvement in GC-IRMS techniques allow detailed ecological and metabolic insights. • Application in ecology, food authenticity, and palaeoecological reconstructions.