Magnetic solid-phase extraction of four β-lactams using polypyrrole-coated magnetic nanoparticles from water samples by micellar electrokinetic capillary chromatography analysis

Abstract In the present research, the application of a polypyrrole coating on Fe3O4 magnetic nanoparticles (PPy/Fe3O4 MNPs) as a sorbent was confirmed. The synthesized magnetic composites were characterized by TEM, FTIR spectroscopy, and XRD. Four β-lactams (oxacillin (OXA), cloxacillin (CLOX), dicloxacillin (DIC), and flucloxacillin (FLU)) were selected as analytes for the experiment. The extracted β-lactams were determined by micellar electrokinetic capillary chromatography-diode array detector (MEKC-DAD). The crucial parameters influencing the extraction efficiency and separation were studied and optimized. Under the optimal conditions, the limits of detection are 1.0 μg•L−1 for OXA, CLOX, FLU, and 0.8 μg•L−1 for DIC. The calibration curves are linear in the range of 2.5–200.0 μg•L−1. The proposed method was applied for the determination of the β-lactams in water samples with satisfactory results. The intra-day relative standard deviations and the inter-day relative standard deviations range from 1.09% to 4.58% and from 2.95% to 7.80%, respectively. It can be concluded that this method is sensitive, convenient, and feasible for the determination of the β-lactams in water samples.