Evaluation of sample extraction methods for minimizing hematocrit effect on whole blood analysis with volumetric absorptive microsampling

Abstract Aim: Volumetric absorptive microsampler (VAMS) was designed to sample a fixed volume of blood regardless of the hematocrit (HCT) levels. Model compounds with a wide range of hydrophobicity were evaluated for their extraction recoveries from VAMS dried blood samples. Results: For the highly hydrophobic compounds, recoveries with methanol or methanol/acetonitrile extraction were higher compared with using the aqueous mixture of methanol or acetonitrile. Extraction with methanol/acetonitrile (1:1) yielded more consistent recovery across the HCT range of 20–70% than using methanol alone, with good linearity, accuracy and precision achieved from 1 to 2000 ng/ml. Conclusion: An organic solvent sample preparation...