Digital image determination of copper in food and water after preconcentration and magnetic tip separation for in-cavity desorption/color development

Walaa Alharbi; Khadijah H Alharbi; Abdullah A Alotaibi; Hassan E M Gomaa; Sami M Abdel Azeem

doi:10.1016/j.foodchem.2024.138435

Digital image determination of copper in food and water after preconcentration and magnetic tip separation for in-cavity desorption/color development

Food Chem. 2024 Jun 1:442:138435. doi: 10.1016/j.foodchem.2024.138435. Epub 2024 Jan 19.

Authors

Walaa Alharbi¹, Khadijah H Alharbi², Abdullah A Alotaibi³, Hassan E M Gomaa⁴, Sami M Abdel Azeem⁵

Affiliations

¹ Department of Chemistry, Science and Arts College, King Abdulaziz University, 21911 Rabigh, Saudi Arabia. Electronic address: wnhalharbe@kau.edu.sa.
² Department of Chemistry, Science and Arts College, King Abdulaziz University, 21911 Rabigh, Saudi Arabia. Electronic address: Khalharbe@kau.edu.sa.
³ Department of Chemistry, College of Science and Humanities, Shaqra University, 11911, AdDawadimi, Saudi Arabia; Water Research Group, College of Science and Humanities at Ad-Dawadmi, Shaqra University, Ad-Dawadmi 11911, Saudi Arabia. Electronic address: aaalotaibi@su.edu.sa.
⁴ Department of Chemistry, College of Science and Humanities, Shaqra University, 11911, AdDawadimi, Saudi Arabia; Department of Nuclear Safety Engineering, Nuclear Installations Safety Division, Atomic Energy Authority, Cairo 11765, Egypt; Water Research Group, College of Science and Humanities at Ad-Dawadmi, Shaqra University, Ad-Dawadmi 11911, Saudi Arabia. Electronic address: hjomaah@su.edu.sa.
⁵ Chemistry Department, Faculty of Science, Fayoum University, 35514 Fayoum, Egypt; Chemistry Department, Al-Quwayiyah College of Science and Humanities, Shaqra University, 11971, Kingdom of Saudi Arabia; Water Research Group, College of Science and Humanities at Ad-Dawadmi, Shaqra University, Ad-Dawadmi 11911, Saudi Arabia. Electronic address: sma13@fayoum.edu.eg.

PMID: 38266415
DOI: 10.1016/j.foodchem.2024.138435

Abstract

A new analytical method for measuring copper in food and water was developed and validated, employing a solid-phase extraction (SPE) technique combined with digital-image-based (DIB) detection. A novel magnetic adsorbent of zinc ferrite/Citrullus colocynthis biochar (ZF@C.BC) was used to preconcentrate copper. A magnetic tip was used to separate the copper-loaded adsorbent from the extraction medium and to dispense it to the DIB plate. In-situ desorption and development of the spot color with iodide-starch reagent were carried out, and a digital image of the developed spots was captured using a smartphone and processed using ImageJ software. The copper adsorption capacity was 91.3 mg g^-1. Desorption was effected using a 0.3 mol L^-1 hydrochloric acid. The preconcentration factor was 300, the limit of detection was 4.8 μg L^-1, the linearity was 16-600 μg L^-1 and the sample throughput was 12 h^-1. The developed approach was validated by analyzing food and water samples, confirming recoveries ≥ 91 % and 88 %, respectively, with RSD ≤ 8.4 %, n = 3.

Keywords: Copper; Digital-image based; Food; Magnetic adsorbent; Water.

MeSH terms

Adsorption
Copper*
Food
Magnetic Phenomena
Solid Phase Extraction / methods
Water*

Substances

Water
Copper