Growth of bimetallic Ni-Co MOFs on a skeleton of electrospun PAN nanofibers and coating on a thin film for SPME of amitriptyline and nortriptyline in urine and plasma samples

In this research, composited bimetallic organic framework-polyacrylonitrile (Ni-Co MOFs-PAN) was applied for thin-film solid phase microextraction (TF-SPME) of tricyclic antidepressant (TCA) drugs from biological samples. The separation and quantification of the analytes were accomplished by HPLC-UV. First, seeded nanofibers with organic ligands were electrospun on a sheet of foil. Then, with the uniform in-situ solvothermal growth of Ni-Co MOFs on the skeletal surface of nanofibers, the nanoparticles were successfully attached to the surfaces without effective bonds and produced a thin layer with a high flexibility, large active surface and abundant functional groups for adsorption. The characteristics of the produced nanocomposite were investigated by Fourier-transform infrared spectroscopy, field emission-scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy and Brunauer-Emmett-Teller analysis. The stirring rate, pH, ionic strength, adsorption and desorption time along with type and volume of desorption solvents as influential factors on extraction efficiencies of the analytes, were optimized by one variable at a time method. Under optimized conditions, wide linear range for analytes in water and plasma matrices were obtained from 0.2 to 1000.0 μg L-1 and 1.0-1000.0 μg L-1, respectively, with R2 ≥ 0.9925. The limits of detection were in the range of 0.06-0.3 μg L-1 in different media. Good repeatability and reproducibility were attained within intra-day, inter-day and film-to-film RSDs% (n = 3) below 3.3 %, 3.9 % and 4.7 %, respectively. Since desirable relative recoveries were calculated between 91.4 % and 100.4 %. The method can be used for the successful extraction and measurement of amitriptyline and nortriptyline as its metabolite in different sampling time from urine and plasma matrices.