A colorimetric chemosensor for quantification of exchangeable Cu2+ in soil

Daniel J Fanna; Luís M P Lima; Gang Wei; Feng Li; Jason K Reynolds

doi:10.1016/j.chemosphere.2019.124664

A colorimetric chemosensor for quantification of exchangeable Cu²⁺ in soil

Chemosphere. 2020 Jan:238:124664. doi: 10.1016/j.chemosphere.2019.124664. Epub 2019 Aug 24.

Authors

Daniel J Fanna¹, Luís M P Lima², Gang Wei³, Feng Li⁴, Jason K Reynolds⁵

Affiliations

¹ School of Science and Health, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia; CSIRO Manufacturing, P.O. Box 218, Lindfield, NSW, 2070, Australia.
² Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal.
³ CSIRO Manufacturing, P.O. Box 218, Lindfield, NSW, 2070, Australia.
⁴ School of Science and Health, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.
⁵ School of Science and Health, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia. Electronic address: j.reynolds@westernsydney.edu.au.

PMID: 31472349
DOI: 10.1016/j.chemosphere.2019.124664

Abstract

Chemosensors have already demonstrated potential for the detection and imaging of metal ions in solutions and biological systems, however, their applications to soil analysis are limited. This study explores the potential of utilizing a chemosensor for the detection of exchangeable Cu²⁺ in soils via qualitative (solution visual color change) and quantitative (UV-Vis spectrophotometry) approaches. Montmorillonite and kaolin clays were doped with Cu(NO₃)₂ solutions from 2.5 to 50 mM, and contaminated soil samples were collected from a historic copper mine. The exchangeable Cu²⁺ was extracted using a standard CaCl₂ cation exchange approach, and the Cu²⁺ concentration in the resulting solutions determined by UV-Vis spectrophotometry, using a chemosensor, and compared to traditional ICP-MS analysis. Analytical results showed that the chemosensor provided a visual response in contaminated soils at concentrations of 25 μM and quantitative detection to concentrations of 1 μM using UV-Vis spectrophotometry. This work demonstrates the first reported chemosensor for exchangeable Cu²⁺ with application to soil systems.

Keywords: Colorimetric chemosensor; Exchangeable copper; Soil.

MeSH terms

Bentonite / chemistry
Cations
Clay / chemistry
Colorimetry / methods*
Copper / analysis*
Mining
Soil
Soil Pollutants / analysis*
Spectrophotometry

Substances

Cations
Soil
Soil Pollutants
Bentonite
Copper
Clay