Polydopamine-functionalized magnetic iron oxide for the determination of trace levels of lead in bovine milk

Mohtaram Ramezanpour; Shahram Naghizadeh Raeisi; Seyed-Ahmad Shahidi; Sorour Ramezanpour; Shahram Seidi

doi:10.1016/j.ab.2019.01.008

Polydopamine-functionalized magnetic iron oxide for the determination of trace levels of lead in bovine milk

Anal Biochem. 2019 Apr 1:570:5-12. doi: 10.1016/j.ab.2019.01.008. Epub 2019 Jan 25.

Authors

Mohtaram Ramezanpour¹, Shahram Naghizadeh Raeisi¹, Seyed-Ahmad Shahidi², Sorour Ramezanpour³, Shahram Seidi⁴

Affiliations

¹ Department of Food Science and Technology, Ayatollah Amoli Branch, Islamic Azad University, Amol, Iran.
² Department of Food Science and Technology, Ayatollah Amoli Branch, Islamic Azad University, Amol, Iran. Electronic address: sashahidy@yahoo.com.
³ Faculty of Chemistry, K.N. Toosi University of Technology, Tehran, Iran.
⁴ Faculty of Chemistry, K.N. Toosi University of Technology, Tehran, Iran. Electronic address: s.seidi@kntu.ac.ir.

PMID: 30689974
DOI: 10.1016/j.ab.2019.01.008

Abstract

In this work, a novel sorbent based on polydopamine-functionalized magnetic ferric oxide (Fe₃O₄) was synthesized and applied for dispersive solid phase extraction of Pb(II) in bovine milk samples. The extracts were analyzed by flame atomic absorption spectrometry (FAAS). The sorbent was characterized with different analytical techniques (XRD, FT-IR, SEM, TEM, VSM and EDX). To reach the maximum extraction efficiency of Pb(II), some effective parameters on both adsorption and desorption steps were optimized with the aid of central composite design and response surface methodology. Under the optimal conditions, the method provided an enhancement factor of 40.5 corresponding to the absolute recovery of 81%. LOD and LOQ were found as 0.13 and 0.43 ng mL^-1, respectively. The calibration curve was linear over the concentration range of 3.0-300 ng mL^-1 (R² = 0.9957). The intra and inter-day precisions (RSD%) of the method were calculated as 3.2% and 5.6%, respectively. Finally, the method was successfully applied for the determination of Pb(II) in different bovine milk samples. The Pb(II) content in one of the investigated milk samples was found to exceed the maximum permissible limit (20 μg L^-1) set by Codex Alimentarius Commission. The relative recoveries were obtained within the range of 86.5-93.6.

Keywords: Diamine functionalized silica-core shell; Dispersive solid phase extraction; Lead; Magnetic nanosorbent; Milk.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adsorption
Animals
Cattle
Ferric Compounds / chemistry
Indoles / chemistry*
Lead / analysis*
Lead / isolation & purification
Limit of Detection
Magnetite Nanoparticles / chemistry*
Milk / chemistry*
Polymers / chemistry*
Solid Phase Extraction
Spectrophotometry, Atomic / methods*

Substances

Ferric Compounds
Indoles
Magnetite Nanoparticles
Polymers
polydopamine
ferric oxide
Lead