Application of silica monoliths for improved storage stability of metabolites in human plasma

In metabolomic studies, sample collection and analysis are typically performed at separate locations, necessitating the transport and storage of samples. However, sample transport and storage conditions are often constrained by the available facilities. Specifically, metabolite levels in biological and food samples can fluctuate due to the activity of endogenous enzymes, depending on the transport and storage conditions. Therefore, in this study, we aimed to achieve metabolite stabilization during storage by sampling human plasma on silica monoliths. Silica monoliths maintained the metabolite samples in a dry state, enabling their transport and storage at high temperatures. Plasmas stored at room temperature and refrigerated were measured using gas chromatography/mass spectrometry (GC/MS), and the fluctuations in metabolites between normal storage and storage on silica monoliths were compared. As a result, fluctuations in several metabolites such as glucose and amino acids were observed during normal storage. However, these were suppressed during storage on silica monoliths. Overall, our findings highlight the efficiency of silica monoliths for sample transport and storage at high temperatures.