Hyphenated MS-based targeted approaches in metabolomics
While global metabolic profiling (untargeted metabolomics) has been the center of much interest and research activity in the past few decades, more recently targeted metabolomics approaches have begun to gain ground. These analyses are, to an extent, more hypothesis-driven, as they focus on a set of pre-defined metabolites and aim towards their determination, often to the point of absolute quantification. The continuous development of the technological platforms used in these studies facilitates the analysis of large numbers of well-characterized metabolites present in complex matrices. The present review describes recent developments in the hyphenated chromatographic methods most often applied in targeted metabolomic/lipidomic studies (LC-MS/MS, CE-MS/MS, and GC-MS/MS), highlighting applications in the life and food/plant sciences. The review also underlines practical challenges–limitations that appear in such approaches.