Developing an ultrasonic-assisted d-μ-SPE method using amine-modified hierarchical lotus leaf-like mesoporous silica sorbent for the extraction and trace detection of lamotrigine and carbamazepine in biological samples

Herein, an ultrasonic-assisted dispersive micro solid-phase extraction method was developed. In this study, we used an amine-modified hierarchical lotus leaf-like mesoporous silica sorbent along with HPLC-UV analysis to simultaneously extract and subsequently measure lamotrigine and carbamazepine in water and biological media. Initially, the synthesis of amine-modified hierarchical lotus leaf-like mesoporous silica sorbent was accomplished and later it was characterized by various techniques such as Scanning Electron Microscopy (SEM), High-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), elemental analysis (CHN), Fourier Transform Infrared spectroscopy (FT-IR), N-2 adsorption-desorption (BET) and thermogravimetric analysis (TGA). Following on, the sorbent was utilized for the extraction of the analytes, and the variables affecting the extraction efficiency were optimized. The optimal conditions for the presented ultrasonic-assisted d-mu-SPE method were: pH 8.5, sorbent amount 24 mg, sonication time in the sorption step 3.5 min, elution by 1.0 mL MeOH: acetic acid (96: 4 (v/v %)) and sonication time for desorption 3 min. Under the optimal condition, the calibration curve was linear over the concentration range of 5-500 mu g L-1, for urine and plasma samples (5.0 mL), and 1-100 mu g L-1 for water samples (10 mL). The practical and feasible limit of quantification (L.O. Q) for the detection of LTG and CBZ by the proposed method was 5.0 mu g L-1 in urine and plasma samples and 1.0 mu g L-1 in water samples. In order to assess the extraction efficiency, the method was applied to various spiked real water samples. The average relative recoveries obtained from the fortified samples varied between 96 and 106% with the relative standard deviations of 4.4-7.9%.