Statistical evaluation of three kinds of sonochemically-prepared magnetic conductive polymer nanocomposites for ultrasound-assisted ligandless uptake of some deleterious metal ions in vegetable samples

In this work, three effectual nanoadsorbents in terms of both the synergically conductive and magnetic properties, named as PTh/surfactant/Fe3O4, PANI/surfactant/Fe3O4, and Ppy/surfactant/Fe3O4, were compared for the simultaneous ligandless preconcentration of Pb2+ and Ni2+ ions from some vegetable samples. The enrichment/detection process was performed by an ultrasound-ameliorated extraction method coupled with micro-sampling flame atomic absorption spectrometry, benefited by the ease of use, high speed, bio-compatibility, low cost, and high preconcentration. Also a simple and effective synthesis of magnetic nanocomposites by the co-precipitation method followed by an efficient in situ sonochemical oxidative polymerization embossed the current procedure. Under optimized conditions obtained by multivariate approaches, pH 5.5, 5 min ultrasonic time, 20 mg of the best nanoadsorbent (PTh/surfactant/Fe3O4), and 250 μL of the eluent resulted in high extraction percentages (85-95%). The calibration curves obtained showed the good liner ranges of 4-400 ng mL−1 and 4-650 ng mL−1 for Ni2+ and Pb2+ ions, respectively, accompanied with low detection limits ranging from 1 to 1.2 ng mL−1. The preconcentration factor was found to be 40. No significant interference of serious foreign agents in the trace analysis of the aforementioned metal ions indicated a good selectivity of the ligandless ultrasound-promoted microextraction procedure, which can be considerably owned by the versatile magnetic nanosorbent. On the other hand, the superb figures of merits demonstrated a great effectiveness of the ultrasonic irradiation in the impressive synthesis of the nanosorbent as well as the facile and efficient microextraction of trace amounts of Ni2+ and Pb2+ ions in complicated plant matrices.