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 approach was developed to optimize extraction recovery and minimize the HCT effect on the analysis of VAMS dried blood samples.
Keywords: hematocrit; microsampling; volumetric absorptive microsampler.