Enhanced urinary stability of peptide hormones and growth factors by dried urine microsampling

Volumetric absorptive microsampling (VAMS) and dried urine spot (DUS) strategies were applied for the collection of microsamples anti-doping testing low-stability peptide hormones growth factors prohibited by World Anti-Doping Agency (WADA). Drying, storage transport conditions, as well pretreatment steps, optimised before liquid chromatography - tandem mass spectrometry (LC–MS/MS) analysis. The analytical method has been fully validated in terms sensitivity (limits quantitation 0.3−10 ng/mL), precision (RSD% < 6.6 %) extraction yields (78–91 %). Dried microsample stability studies (90 days) have performed compared to fluid stability. Significantly higher losses observed stored at −20 °C (up 55 −80 29 than room temperature (< 19 final analysis protocols allow microvolumes, unlikely be tampered, stably storable shippable with no particular precautions possible peptides hormones.