Determination of acidic, basic and amphoteric drugs in biological fluids and wastewater after their simultaneous dispersive micro-solid phase extraction using multiwalled carbon nanotubes/magnetite nanoparticles@poly(2-aminopyrimidine) composite

Determining of acidic, basic and amphiprotic drugs from different samples simultaneously is a remarkable and discussible topic in sample preparation methods. In this work, an easy and fast dispersive micro-solid phase extraction (D-μ-SPE) method was developed using a magnetic multiwalled carbon nanotubes/Fe3O4@poly(2‑aminopyrimidine) (MWCNTs/Fe3O4@PAPy) as a viable and efficient sorbent to preconcentrate and determine five model analytes in three different classes (nortriptyline, cetirizine, naproxen, diclofenac and ibuprofen). The nanosorbent was characterized by diverse characterization techniques. After the extraction step, HPLC-photo diode array detection (HPLC-DAD) was employed to quantify the model analytes. The effects of various parameters on the dispersive magnetic solid phase extraction method were explored thoroughly via design of experiment and desirability function. The highest extraction performance was obtained under the conditions of: a sample pH of 2, a sorbent amount of 8 mg, a sorption time of 5 min, a salt concentration of 20% w/v in the sample solution, 120 μL 0.01 mol L−1 HCl in acetonitrile as an eluent, and an elution time of 2 min. By employing the optimum conditions detection limits and linear dynamic ranges were obtained in the range of 0.07-3.5 μg L−1 and 0.25-1500 μg L−1, respectively. The relative standard deviations (n = 5) were between 1.4% and 10.5%. Eventually, this method was simply applied for determination and extraction of target analytes in different samples.