Liquid Chromatographic Methods for Microsampling in Sports Drug Monitoring: Progress in DBS and VAMS

Sports drug monitoring has long relied on urine testing and, to a lesser extent, venous blood collection. Although this framework remains effective for many prohibited substances, it is increasingly challenged by demands for minimally invasive sampling, closer reflection of circulating exposure, improved peptide and protein detection, and field-compatible logistics. This review critically examines chromatographic and mass-spectrometric methods using dried blood spots (DBSs) and volumetric absorptive microsampling (VAMS) for sports drug monitoring, focusing on analytical performance, translational feasibility, and barriers to routine implementation. Evidence from anti-doping studies is integrated with broader microsampling bioanalysis literature. DBS workflows have shown utility for stimulants, tramadol, glucocorticoids, steroid esters, erythropoietin receptor agonists, growth hormone secretagogues, insulin-like growth factor 1, and emerging RNA or transgene biomarkers. VAMS further strengthens quantitative microsampling by reducing volume uncertainty and supporting monitoring of endogenous steroids, thyroid hormones, and longitudinal markers. However, regulatory readiness remains constrained by analyte-specific detection windows, imperfect device comparability, and stringent evidentiary requirements. Particular attention is given to liquid chromatographic workflows, including sample extraction, clean-up, derivatization, matrix effects, extraction efficiency, stability, and device-to-device transferability because these steps determine whether DBS and VAMS data can support scientifically defensible anti-doping decisions.