ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Magnetic dispersive micro-solid-phase extraction for the preconcentration and extraction of lead (II) and cadmium ions from environmental samples using magnetic CoFe₂O₄ @ SiO₂@4-aminobenzoic acid-functionalized graphene oxide as a green and efficient sorbent

Vahideh Khorasani, Razieh Sanavi Khoshnood, and Hamid Gholamhosseinian

Department of Chemistry, Mashhad Branch, Islamic Azad University, Mashhad, Iran

E-mail: rskhoshnood@yahoo.com

Received: 28 March 2021  Accepted: 19 August 2021

Abstract:

A magnetic dispersive micro-solid-phase extraction as a simple and efficient sample preparation procedure was developed to extract lead (II) and cadmium (II) ions. The microextraction method was enhanced using an ultrasonic bath as a suitable device and a surfactant as a dispersion agent to disperse a sorbent into a low volume of distilled water before injecting it into the sample solution. This procedure increases the sorbent dispersion efficiency and decreases the dispersion time to reduce sorbent degradation. Also, green and selective sorbent (magnetic CoFe₂O₄ nanoparticles @ SiO₂ @ 4-aminobenzoic acid-functionalized graphene oxide) was prepared based on functionalization of graphene oxide with 4-aminobenzoic acid and its magnetization with CoFe₂O₄ nanoparticles using the solgel technique. Several factors affecting the microextraction process of lead (II) and cadmium (II) ions, including the type of desorption solvent and dispersing solvent, extraction time, desorption time, dispersion time, sample solution volume, sorbent amount, and pH of the solution, were optimized by experimental design and one factor at a time strategy. Under the optimum condition, the calibration curves for the determination of lead (II) and cadmium (II) ions were linear at the concentration ranges of 13.2–235.0 and 16.8–240.0 ng L⁻¹ with a determination coefficient (R²) of 0.9866 and 0.9839, respectively. Limit of detection and relative standard deviation (n = 3) for the determination of lead (II) and cadmium (II) ions were lower than 5.4 ng L⁻¹ and 4.2%, respectively. The application of the method for analyzing several real water samples indicated that the technique has an excellent relative recovery in the range of 96.2–102.2% with relative standard deviations of less than 4.9%.

Keywords: Dispersive micro-solid-phase extraction; Environmental water samples; Lead (II) ion; Cadmium ions; Surfactant; Flame atomic absorption spectrophotometry

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-021-01833-2

Chemical Papers 75 (12) 6639–6650 (2021)