Cellulose acetate fibers were modified with a gelatin cryogel adsorbent incorporating an iron–carboxylate metal–organic framework and hypercrosslinked polymer composite. The hybrid adsorption materials facilitated the adsorption ability toward polycyclic aromatic hydrocarbons and were entrapped into gelatin cryogel to be hierarchically coated on cellulose acetate fibers which helped to reduce the clogging problem of packed adsorbent. The composite adsorbent was employed as the solid phase of an in-syringe miniaturized solid-phase extraction system. The adsorbent was packed into the needle hub of a disposable syringe and used to extract and preconcentrate polycyclic aromatic hydrocarbons in water sample. The fabricated porous composite adsorbent was characterized and extraction conditions were optimized to achieve the best extraction performance. High-performance liquid chromatography was employed to separate and quantify extracted PAHs. The developed analysis method provided a linear range of 0.020–50 µg L⁻¹ for phenanthrene and benzo(b)fluoranthene, 0.010–50 µg L⁻¹ for pyrene, 0.0020–50 µg L⁻¹ for benzo(a)anthracene, and 0.0050–50 µg L⁻¹ for benzo(a)pyrene and dibenzo(a,h)anthracene. The limits of detection ranged from 0.5 to 5.0 ng L⁻¹. Recoveries ranged from 89 to 98% with RSDs below 7%. The good stability of the adsorbent allowed up to 21 cycles of efficient extraction and desorption.