Comparison of Biotage® Extrahera™ vs. Manual Sample Processing Using a Vacuum Manifold - Extraction of 25-OH Vitamin D from Plasma

Importance of the Topic

Accurate and reproducible measurement of 25-hydroxyvitamin D (25-OH D2 and D3) in plasma or serum is critical for clinical diagnostics and nutritional studies. Supported liquid extraction (SLE) simplifies sample cleanup and enhances analyte recovery compared to traditional protein precipitation. Automating this step improves throughput, consistency, and reduces manual error, making it highly relevant for clinical laboratories and quality control in pharmaceutical research.

Objectives and Study Overview

This technical note compares an automated extraction workflow using the Biotage Extrahera with a traditional manual vacuum manifold method. Both approaches apply ISOLUTE SLE+ 96-well plates to isolate 25-OH vitamin D2 and D3 from pooled plasma spiked at 30 ng/mL, with deuterated D3 as internal standard. The study evaluates extraction efficiency, precision (%RSD), and absolute peak areas measured by LC-MS/MS.

Methodology and Instrumentation

• Sample Preparation: Pooled stripped plasma fortified with 25-OH D2, D3 and 25-OH D3-d6 at 30 ng/mL. Pre-treatment with 1:1 water/isopropanol, load 300 µL onto SLE+ plates.
• Extraction: Two cycles of 750 µL heptane elution. Automated positive pressure via Extrahera vs. manual vacuum manifold. Final solvent recovery by pressure or vacuum.
• Concentration: Evaporation to dryness (TurboVap 96 at 37 °C or SPE Dry at 40 °C), reconstitution in 100 µL water/methanol (30:70), plate mixing 10 min.
• Chromatography: Waters ACQUITY UHPLC, Restek Pinnacle DB BiPhenyl (50 × 2.1 mm, 1.9 µm), mobile phase 2 mM ammonium formate/0.1% formic acid and methanol/0.1% formic acid (80:20), 0.4 mL/min, 15 µL injection.
• Mass Spectrometry: Waters Quattro Premier XE, MRM transitions for D2, D3, and D3-d6 with optimized cone voltages and collision energies.

Main Results and Discussion

• Peak Area Improvement: Automated extraction yielded 5–7.6% higher average peak areas for 25-OH D2 and D3 compared to manual.
• Precision (%RSD): Extrahera improved precision for 25-OH D3 by 11.8% (5.9% vs. 6.7%), while 25-OH D2 showed a non-significant 3.6% increase in %RSD.
• Serum Matrix Validation: Comparable recoveries in serum (97–100%) for both methods, demonstrating robustness across matrices.
• Calibration Curves: Linear responses (r² > 0.99) across 1–100 ng/mL in PBS-BSA and commercial standards, with no significant bias between methods.

Benefits and Practical Applications

Automated SLE extraction using the Biotage Extrahera enhances laboratory efficiency by reducing hands-on time and variability. The observed increase in analyte signal and improved precision supports its adoption in high-throughput clinical and research settings, facilitating reliable vitamin D quantification for patient monitoring and nutritional studies.

Future Trends and Applications

• Integration of SLE automation with digital laboratory workflows for real-time data tracking and quality control.
• Extension to other lipid-soluble vitamins and biomarkers requiring high recovery and low matrix effects.
• Miniaturization of extraction plates to further reduce solvent consumption and waste.
• Coupling with advanced MS platforms (e.g., high-resolution MS) to broaden analyte panels in clinical metabolomics.

Conclusion

Automating the supported liquid extraction of 25-OH vitamin D using the Biotage Extrahera delivers higher analyte recovery, enhanced precision for D3, and consistent performance across plasma and serum matrices. These improvements position automated SLE as a reliable alternative to manual methods in routine vitamin D analysis.

Reference

No external literature references cited in this application note.