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

A highly sensitive electrochemical probe for trace determination and chemical speciation of lead in water and foodstuffs using Thorin-I as a selective chelating agent

Mohammad Soror El-Shahawi, Abdulaziz Abraheem Alsibaai, Abdulaziz Saleh Bashammakh, and Hakeem Kaid Al-Ariqei

Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia

E-mail: malsaeed@kau.edu.sa

Received: 21 October 2020  Accepted: 28 December 2020

Abstract:

A simple and low-cost differential pulse-adsorptive cathodic stripping voltammetry (DP CSV) approach has been established for trace determination and speciation of Pb using Thorin-I as selective chelating agent. The established assay was based upon controlled preconcentration of Pb–Thorin complex at pH 8.3–9.0 at a hanging mercury dropping electrode (HMDE). The resulting cathodic peak current (I_p,c) at − 0.56 V was then measured versus Ag/AgCl reference electrode. The plot of I_p,c versus Pb concentration under the optimized parameters was linear in the concentration range 3.5 × 10^–10 − 5.0 × 10^–7 mol L⁻¹. The lower limits of detection (LOD) and quantification (LOQ) of Pb were 1.05 × 10^–10 and 3.5 × 10^–10 mol L⁻¹, respectively. The planned assay was satisfactorily applied for total analysis and speciation of Pb in various water and food samples. Validation of the developed probe was successfully achieved by analysis of Pb in certified reference material.

Keywords: Certified reference materials; Lead; Speciation; Stripping voltammetry; Thorin-I

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01500-y

Chemical Papers 75 (6) 2395–2406 (2021)