| Abstract: | In this work, molecularly imprinted nanoparticles (MINPs) were applied as selective adsorbent for ultrasound‐assisted micro‐solid‐phase extraction (UAMSPE) of doxepin (DP) from human plasma samples, which was then cleaned up, pre‐concentrated and subjected to HPLC. The MINPs were synthesized based on a non‐covalent approach by precipitation polymerization utilizing methacrylic acid and styrene as functional monomers, DP as template, ethylene glycol dimethacrylate as cross‐linker and 2,2‐azobisisobutyronitrile (AIBN) as initiator. The obtained MINPs were characterized by Fourier transform‐infrared and field emission scanning electron microscopy. Factors influencing the efficiency of UAMSPE such as sonication time, volume of eluent solvent and amount of sorbent were investigated using a central composite design and the optimal points were identified as 4 min of sonication time, 380 μL of eluent solvent and 30 mg of sorbent. Under optimized conditions, the proposed method has linear responses in the range of 0.2–2000 ng mL–1, with a satisfactory limit of detection of 0.04 ng mL–1 and limit of quantification of 0.11 ng mL–1. |
