Magnetic Solid Phase Extraction of Pb (II) from Water, Rice, and Tomato Samples with Carbonized Cotton Cloth@zeolite Imidazolate Framework-71/ Fe₃O₄/ Polythionine prior to its Flame Atomic Absorption Spectrometric Detection

A sustainable fabricated sorbent, carbonized cotton cloth/ zeolite imidazolate framework-71/ Fe3O4/ polythionine (CC@ZIF-71/Fe3O4/PTh), was fabricated then utilized for separation and preconcentration of lead in tomato, rice and, water samples applying magnetic solid phase extraction (MSPE) tandem Flame Atomic Absorption Spectrometry (FAAS). The fabrication steps of the sorbent were performed by synthesis of zeolitic imidazolate framework-71 nanocrystalline in attending the carbonized cotton cloth and then thionine was polymerized on the surface of CC@ZIF-71/Fe3O4. These nanomaterials were adjusted to enhance the applicability of sorbent. Characterization of sorbent was carried out by using FE-SEM, FT-IR spectroscopy, and XRD technique. The magnetic solid phase extraction efficiency and analytical parameters of this proposed method such as pH, sorbent amount, the effect of interfering ions, desorption condition, extraction time, and the amount of chelating agent were examined. The relative standard deviation (RSD, n=10) of Pb was obtained at 3.5%. The limit of detection (LOD) (n = 10) and limit of quantification (LOQ) were determined at 1.7 and 10.0 μg L-1, respectively. The accuracy of the novel proposed procedure was assessed by analyzing certified reference material. Finally, the proposed process was employed to assess lead in water, tomato, and rice samples.