A ready-to-use deep eutectic solvent-immersed polypropylene fabric cap microextraction strategy for nonsteroidal anti-inflammatory drugs analysis in plasma: a proof-of-concept study

Abstract

The determination of non-steroidal anti-inflammatory drugs (NSAIDs) is important for pharmaceutical analysis and bioanalytical research. In this study, a proof-of-concept deep eutectic solvent-immersed polypropylene fabric cap microextraction (DES-PPF-CME) method was developed for the determination of NSAIDs in plasma. The proposed device integrates polypropylene fabric immobilized with a hydrophobic deep eutectic solvent (DES) into a disposable centrifuge tube cap, enabling analyte extraction via simple shaking without the need for complex instrumentation. This configuration represents a new format of supported liquid membrane extraction, offering a simplified, ready-to-use workflow that is amenable to batch processing. Under optimized conditions, including 18 µL of DES composed of methyltrioctylammonium bromide and decanoic acid at a molar ratio of 1 : 3, a sample pH of 5.3, an extraction time of 22 min, and desorption with 0.2 mL of acetonitrile for 3 min, extraction recoveries of 59.6–84.4% were obtained. When coupled with high-performance liquid chromatography–ultraviolet detection, the method demonstrated acceptable linearity (R² ≥ 0.9839), low limits of detection (1.1–19.7 ng mL⁻¹), and satisfactory precision (RSD ≤ 8.6%) in spiked plasma samples. These initial findings suggest that the disposable and easy-to-operate DES-PPF-CME configuration is a promising platform for further development toward the routine analysis of NSAIDs in complex biological matrices.