Evaluation of Sample Extraction Methods for Minimizing Hematocrit Effect on Whole Blood Analysis with Volumetric Absorptive Microsampling

Abstract

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.

Volumetric absorptive MicroSampling vs. other blood sampling materials in LC–MS-based protein analysis – preliminary investigations

“…These two proteins have the highest hydrophobicity of the six model proteins. Reduced recovery from VAMS has previously been seen for hydrophobic analytes (small molecules) [49], and may therefore also explain the reduced recoveries for βlactoglobulin and myoglobin in the present study.…”

“…The use of a wider hct range may explain why an hct effect was shown for VAMS in the present paper. Hct can also influence the recovery of analyte from the sampling material [49,56], give different degree of matrix effects [51] which might result in both increased ion enhancement and ion suppression. In addition, hct may influence the digest efficiency.…”

“…Differences in digest efficiency were however unlikely as 10 µL of blood (eluted from the material) was diluted in a total volume of 200 µL of buffer prior to digest. Optimization of the elution buffer may eliminate the hematocrit effects, as shown by others [49,56], but ABC buffer was required in the present project as described in the previous section. To sum up, removal of hematocrit bias will not solely be solved by changing the sampling material and further optimization of elution process or the following sample preparation steps is required to avoid hematocrit bias for the volumetric sampling material.…”

Official International Association for Therapeutic Drug Monitoring and Clinical Toxicology Guideline: Development and Validation of Dried Blood Spot–Based Methods for Therapeutic Drug Monitoring

“…In this context, heated extraction, as well as the use of a mixture of organic solvents rather than a single organic solvent may be helpful. 62,63,66,67 Furthermore, the use of a different collection card may also help to resolve this problem. Possibly, depending on the target population, the procedure can be repeated with less extreme low and high HT values, to evaluate whether acceptable results are obtained for a more limited HT span.…”

Emerging trends in paper spray mass spectrometry: Microsampling, storage, direct analysis, and applications

“…To help reduce bias in VAMS assays, samples should be collected at room temperature or 37°C, but not at colder temperatures such as 4°C (Fang et al, ), with a recommended drying time of 2 hr (Parker et al, ). For optimal reduction in hematocrit effects, the type of extraction solvent has been found to be extremely important as it affects analyte recoveries (Ye & Gao, ). Additional workup steps, such as sonication, prewetting, and liquid‐liquid extraction may also be performed to further improve the recovery (Xie et al, ).…”