Thin film microextraction of apixaban from plasma based on the covalent organic framework coated on a mesh prior to liquid chromatography-tandem mass spectrometry.

In this research, a new covalent organic framework was synthesized and utilized as a coating in thin film microextraction for the extraction of apixaban from plasma samples. This coating was applied to the mesh modified through immersion in a HF solution. The extracted drug was then analyzed using liquid chromatography-tandem mass spectrometry. By combining the high specific surface area and selectivity of the covalent organic framework, along with integrating the innovative thin film microextraction method and a sensitive analysis system, an efficient analytical approach was achieved. The target analyte was preconcentrated and extracted by immersing of the covalent organic framework-coated mesh as an absorbent into the biological sample. Subsequently, a sonication process was conducted for a specific duration. Following this, the extracted analyte was desorbed using acetonitrile as the elution solvent. The effective parameters of the proposed technique were optimized by using "one-parameter-at-a-time" strategy and the optimal conditions were selected. By integrating the developed method notable achievements were made in the terms of low limits of detection and quantification (0.17 and 0.56 µg/L, respectively), a wide linear range (0.05-250 µg/L), intra- and inter day precisions (with relative standard deviations of ≤14 %), as well as satisfactory extraction recoveries (53 % and 54 % in plasma and deionized water, respectively). Hence, it can be concluded that the introduced technique exhibits high efficiency and reliability when applied to biological samples.