Development of a new procedure for selecting internal standards for gas chromatography/mass spectrometry-based plasma...

Mass spectrometry, including gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry, and capillary electrophoresis/mass spectrometry, can analyze many different molecules in a single measurement, facilitating metabolome analysis. In metabolome analysis, internal standards (ISs) play an important role in ensuring the accuracy of such measurements. The chemical structural characteristics of molecules have little impact on which molecules can be analyzed in GC/MS; therefore, it is difficult to select suitable ISs for GC/MS-based metabolome analysis. In this study, a procedure for selecting ISs for GC/MS-based metabolome analysis based on hierarchical cluster analysis, which also corrects for differences between facilities, was investigated. In Experiment A, hierarchical cluster analysis using a dataset obtained from the three facilities was carried out, and the candidates of the ISs for each classified group were selected. In Experiment B, the usage of the IS candidates selected by hierarchical cluster analysis tended to result in the lower values of percentage relative standard deviation. This study proposes the use of hierarchical cluster analysis to select ISs for GC/MS-based plasma metabolome analysis, which may also lead to improved accuracy of the analytical data obtained from GC/MS-based plasma metabolome analysis.