A Comprehensive Dual Platform, End-to-end Workflow for Metabolic Profiling of Dried Blood Microsamples.

Blood microsampling (BµS) has emerged as a robust, minimally invasive alternative to traditional venipuncture, enabling the collection of low-volume specimens outside conventional clinical settings. By supporting decentralized sampling and improving patient adherence, these devices can be integrated with advanced omics technologies to facilitate large-scale and longitudinal study designs. However, successful implementation requires optimization of multiple critical steps, from sample collection and storage to extraction and analytical preparation. In this work, we propose a comprehensive end-to-end untargeted metabolomics workflow for BµS, with an emphasis on key parameters governing sample preparation and analytical performance. Volumetric absorptive microsampling (VAMS) devices were evaluated using two complementary platforms: reversed-phase liquid chromatography coupled to mass spectrometry and gas chromatography coupled to mass spectrometry. Application of the optimized workflow demonstrated broad metabolomic coverage across diverse chemical classes, highlighting the potential of VAMS-based sampling to support scalable, decentralized metabolomics studies while maintaining analytical robustness, reproducibility, and biological relevance.