Electrospun chitosan modified montmorillonite/polyvinyl alcohol nanofibers as suitable coating for fiber-in-tube solid-phase microextraction of trace amounts of tricyclic antidepressants in biological fluids

• Chitosan intercalated montmorillonite nanocomposite was synthesized. • A PVA/CA/OMMT coating for SPME was prepared by electrospinning method. • Coating presented high extraction ability for tricyclic antidepressants drugs. • FIT-SPME was applied for direct analysis of the drugs in biological samples. • Method demonstrates exceptional performance across most AGREE criteria. Chitosan intercalated montmorillonite and polyvinyl alcohol-citric acid (PVA/CA) nanofibers were electrospun onto stainless steel wires. The fibers were placed inside a stainless steel tube and utilized for fiber-in-tube solid phase microextraction (FIT-SPME) to detect trace levels of tricyclic antidepressant drugs (TCAs) in biological samples. The analytes were separated and quantified using gas chromatography coupled with mass spectrometric detection (GC–MS). The effects of various parameters on the extraction efficiency, including pH (9), extraction time (25 min), extraction flow rate (3 mL min -1 ), salt addition (0 % w/v), type of eluent (ethanol 99 %), eluent volume (300 µL), and desorption flow rate (70 µL min -1 ), were investigated and optimized. Under optimal conditions, the linear dynamic range for doxepin, and sertraline was found to be 0.08–750.0 ng mL -1 ; for amitriptyline, desipramine, and trimipramine, it was 10.0–750.0 ng mL -1 ; and for carbamazepine and maprotiline, it was 50.0–750.0 ng mL -1 . The proposed method exhibited low limits of detections in the range of 0.02–15.2 ng mL -1 . Additionally, coefficients of determination (R²) exceeding 0.9911 were achieved, indicating excellent linearity for the calibration curves. To assess the feasibility of the FIT-SPME-GC–MS method, extraction and analysis of TCAs were performed on plasma and urine samples. Relative recovery percentages (RR%) ranged from 90.3 % to 117.6 %.