Development of Air‐assisted Liquid‐Liquid Microextraction in the Primary Amine‐based Supramolecular Solvent for Determination of Tricyclic Antidepressants Prior to High‐Performance Liquid Chromatography‐Ultraviolet Detection

This study developed an air-assisted liquid-liquid microextraction method using a primary amine-based supramolecular solvent (SUPRAS) and a monoterpenoid as a coacervation agent to determine two tricyclic antidepressants (amitriptyline and nortriptyline) from human plasma and urine samples prior to high-performance liquid chromatography analysis. The extraction of two antidepressant drugs was performed using a micellar solution of the primary amine (1-octylamine) as an amphiphile. A monoterpenoid (thymol) was utilized to initiate the coacervation process. The homogeneous solution of the SUPRAS was dispersed into the aqueous sample phase using air bubbles introduced through a syringe. The important characteristic of the suggested SUPRAS is the elimination of toxic solvents, such as tetrahydrofuran, and the removal of dispersive solvents. The experimental parameters, such as primary amine type, monoterpenoid type, extraction cycle number, and pH, were investigated. The limits of detection (signal-to-noise ratio [S/N] = 3) and quantification (S/N = 10) were achieved to be 0.5-0.6 and 1.5-1.8 µg/L with a linear range of 1.5-4000 and 1.8-4000 µg/L in urine and plasma samples. The percentage relative standard deviation values (n = 5) were 2.9%-3.5% for amitriptyline and 4.1%-4.2% for nortriptyline. The proposed method has been applied successfully to the spiked urine and plasma samples, achieving recoveries in the range of 93.1%-95.2.