Abstract
Blood microsampling (BμS) has emerged as a promising approach in the analysis of endogenous metabolites, especially for its minimally invasive sample collection and simplified analysis logistics. Different BμS devices are currently available; although they share similar concepts for sample collection, matrix variations might impact the analytical outcomes. The present work aims to evaluate the global metabolic profiles obtained from
different BμS devices, namely Dried Blood Spots (Whatman), Volumetric Absorptive Microsampling (Mitra), and Capitainer cards, compared to plasma. For this purpose,
venous blood was collected from 10 healthy, overnight-fasted individuals and loaded onto the devices. Plasma was produced from the same venous blood. Two untargeted metabolomic profiling methods were used: a reversed-phase UHPLC system coupled to a TIMS-qTOF MS operating in DDA mode and a GC-MS method with methoxyamine and trimethylsilane derivatization. For LC-MS, ESI-MS conditions were optimized to enhance sensitivity and reduce in-source fragmentation. Extraction protocols, optimized for each technique, involved a mixture of MeOH-H2O
(60:40, v/v) for LC-MS analysis and neat MeOH for GC-MS. Data pre-processing was performed using MSDial, XCMS, and Hystar software. Statistical analysis was performed in SIMCA. Quality control samples – injected periodically throughout the run – and internal standards were used to account for
instrumental drift, perform normalization, and verify the data quality.
The different matrices were compared regarding the number, intensity, and annotation of features. Results indicate that BμS devices, especially Mitra and Capitainer, provide metabolic profiles comparable to, or even more informative than, those obtained from plasma.
(The work has been Funded by the European Union under the HORIZON-MSCA-2021 project 101073062 : HUMAN – Harmonising and unifying blood metabolic analysis networks.)