Improved Point-of-Care Mass Spectrometry Analysis with Thin-Layer Chromatography-Based Two-Dimensional Separation and Spray Ionization

Point-of-care testing (POCT) involves administering rapid on-site analysis to provide fast biochemical testing results. POCT reduces delays in clinical decision-making and eliminates the need to transport and prepare clinical samples for immediate diagnosis or clinical intervention by healthcare professionals. Herein, a novel methodology integrating thin-layer chromatography-based two-dimensional separation with miniature mass spectrometry was developed for rapid on-site clinical analysis. As a proof-of-concept demonstration, γ-aminobutyric acid, 2-hydroxyglutarate, and N-acetyl-L-aspartic acid, which are widely known as biomarkers for brain gliomas, were selected as model analytes for method development and validation. The proposed approach exhibited satisfactory analytical performance, with 1 ng/mL limits of detection, 2 ng/mL limits of quantitation, and recoveries in the range of 85.9–107.2%. Additionally, on-TLC derivatization and reactive spray ionization strategies were utilized to enhance the mass spectrometric signals compared to un-derivatized analysis. This method was applied to analyze clinical samples, showcasing its attractive potential outside the laboratory.

In this work, a miniature MS-based POCT method was developed to analyze glioma biomarkers followed by TLC-based two-dimensional separation. The analytical performance of the developed method was evaluated in terms of sensitivity, linearity, recovery, and matrix effects. In addition, two on-TLC derivatization and reactive spray ionization strategies were explored, leading to enhanced sensitivity. This method addresses the limitations of delayed clinical decision-making caused by existing testing methods and exhibits great promise for future POCT applications.