A two-step sample preparation technique based on dispersive micro solid-phase extraction combined with coacervative microextraction is presented for preconcentration and determination of tricyclic antidepressant drugs in biological samples. An important feature of the method is the application of hydrophobic magnetic nanoparticles, which in combination with coacervative microextraction method enables development of rapid and efficient extraction procedure in order to achievement of a high extraction efficiency. Simultaneous optimization by experimental design lead to improvement of method with low cost which supply useful information about interaction among variables. Under the optimized conditions, a linear range of 5–1000 ng mL−1 with detection limits from 0.51 to 1.4 ng mL−1 were obtained for target analytes. The method was successfully used for the determination of analytes in biological fluids (plasma and urine) with relative recoveries in the range of 89–105% (RSDs < 3.5%)
