Hematocrit-independent recovery is a key for bioanalysis using volumetric absorptive microsampling devices, MitraTM

Background: A novel microsampling device, Mitra(TM), was evaluated for bioanalysis of E6005 and its O-desmethylated metabolite in human whole blood using an UPLC-MS. Results: A constant volume of blood samples was absorbed onto the tip of Mitra, the analytes were extracted by various solvents and then detected by UPLC-MS. Recovery of the analytes was high in acetonitrile-water (1:1, v/v) but was dependent on hematocrit (Hct) without sonication process, which led to biased accuracy at low and high Hcts. Inclusion of sonication process in extraction improved recovery at high Hct to yield acceptable accuracy across Hcts. Conclusion: Optimization of extraction process to achieve high recovery regardless of Hct is critical in accurate bioanalysis via Mitra.