Novel sampling and gas-phase derivatization strategy: Proof-of-concept by profiling ionic polar metabolites using gas chromatography-mass spectrometry.

Metabolomic research involves the comprehensive analysis of metabolites in biological samples and has many applications. Gas chromatography-mass spectrometry (GC-MS) is an established and widely used approach for metabolic profiling. However, sample preparation and metabolite derivatization are time-consuming, and derivatization options are limited. We propose gas-solid phase derivatization (GSPD) as a novel sampling and derivatization method that uses a silica monolith substrate and gaseous derivatization reagents for metabolomics using GC-MS. We developed a method to measure the organic acids and sugar phosphates responsible for glycolysis and the tricarboxylic acid (TCA) cycle. GSPD simplifies the sample preparation and can be applied to derivatization reactions that are difficult to perform in solution owing to solvent limitations. The developed method was applied to human plasma and tomato pulp and was shown to have a higher detection performance than the conventional method. This study provides a strategy to simplify sample preparation and expand derivatization options for GC-MS-based metabolomics.