MOF-199@ tryptophan coated on magnetic bar for stir-bar sorptive extraction of warfarin and aspirin from biological samples followed by quantification through HPLC-UV.

Tryptophan-functionalized MOF-199 was synthesized via a simple solvothermal method and employed as a novel sorbent for the development of stir-bar sorptive extraction (SBSE) method. The extraction efficiency of the SBSE method was systematically investigated using warfarin and aspirin as model compounds. The extracted drugs were analyzed using high-performance liquid chromatography with ultraviolet detection (HPLC-UV). Key parameters affecting SBSE, including stirring rate, desorption solvent, pH, extraction and desorption time, and salt concentration, were optimized, resulting in 800 rpm stirring rate, 5 min extraction, 1 min desorption, 11 % (w/v) salt concentration, 100.0 μL desorption solvent, and pH = 3.0 as optimal condition. Under the condition, the method exhibited excellent linearity (0.10-200.00 μg L-1 for aspirin and 0.10-100.00 μg L-1 for warfarin), low limits of detection (0.04 and 0.03 μg L-1) and limits of quantification (0.13 and 0.09 μg L-1), and satisfactory precision (%RSD = 4.40-7.60 % for aspirin and 5.10-6.50 % for warfarin). Enrichment factors (EFs) of 56.00 and 64.00 were achieved for aspirin and warfarin, respectively. The proposed SBSE-HPLC-UV method was successfully applied to biological samples, including plasma and urine, demonstrating high reproducibility, efficiency, and suitability for trace-level drug analysis. These results highlight the potential of tryptophan-functionalized MOF-199 as an effective sorbent for analytical applications in pharmaceutical and biological matrices. The method was further evaluated using the Blue Applicability Grade Index (BAGI), achieving a score of 82.5.