{"title":"Medium scale-up synthesis of nanomaghemite as an inhibitor of cadmium uptake in seedlings of Theobroma cacao L","authors":"","doi":"10.1016/j.jafr.2024.101295","DOIUrl":null,"url":null,"abstract":"<div><p>The aim of this research was to show that the absorption of divalent cadmium ions (Cd<sup>2+</sup>) in <em>Theobroma cacao</em> L. seedlings can be controlled and adjusted by remediation with maghemite (γ-Fe<sub>2</sub>O<sub>3</sub>) nanoparticles (NPs), i.e., leading to the low tolerance limits established by the European Union (EU) in 2014 for Cd in products made from cocoa. The research had two stages; the first one involved the medium scale synthesis of 92 g of 15 nm γ-Fe<sub>2</sub>O<sub>3</sub> NPs via room temperature chemical co-precipitation of ferrous salts and their characterizations using diverse physicochemical techniques. In the second stage, and for the first time, three doses of these γ-Fe<sub>2</sub>O<sub>3</sub> NPs (1, 2, and 4 g) were applied to the substrate of cocoa seedlings of genotypes ICS 39, ICS 95, and CCN 51 for three months of exposure. A morphological analysis revealed non-significant toxic effects on the seedlings’ height, leaf area, and stem diameter among the genotypes and tested doses. The results of the atomic absorption analysis of the treatment with 4 g of γ-Fe<sub>2</sub>O<sub>3</sub> NPs showed a concentration of 0.10 mg kg<sup>−1</sup> of Cd<sup>2+</sup>, a limit lower than the control and the recommended value by the 2014 EU regulation. Thus, the transport and/or absorption of the Cd<sup>2+</sup> toxic metal were significantly inhibited, since up to 74 % of Cd<sup>2+</sup> uptake in the genotype ICS 95 was experimentally observed. Also, the environmental Fe-dynamics in the seedlings and soils demonstrated no transport of γ-Fe<sub>2</sub>O<sub>3</sub> NPs to the seedlings. Thus, the study found that the Cd<sup>2+</sup> adsorption in remediated soil using γ-Fe<sub>2</sub>O<sub>3</sub> NPs involves three steps: electrostatic exchange, Fe-oxide adsorption, and substrate-γ-Fe<sub>2</sub>O<sub>3</sub> NPs complexation and precipitation.</p></div>","PeriodicalId":34393,"journal":{"name":"Journal of Agriculture and Food Research","volume":null,"pages":null},"PeriodicalIF":4.8000,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666154324003326/pdfft?md5=17ad6b74bf3ebc01bc33410951cdeb57&pid=1-s2.0-S2666154324003326-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Agriculture and Food Research","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2666154324003326","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"AGRICULTURE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
The aim of this research was to show that the absorption of divalent cadmium ions (Cd2+) in Theobroma cacao L. seedlings can be controlled and adjusted by remediation with maghemite (γ-Fe2O3) nanoparticles (NPs), i.e., leading to the low tolerance limits established by the European Union (EU) in 2014 for Cd in products made from cocoa. The research had two stages; the first one involved the medium scale synthesis of 92 g of 15 nm γ-Fe2O3 NPs via room temperature chemical co-precipitation of ferrous salts and their characterizations using diverse physicochemical techniques. In the second stage, and for the first time, three doses of these γ-Fe2O3 NPs (1, 2, and 4 g) were applied to the substrate of cocoa seedlings of genotypes ICS 39, ICS 95, and CCN 51 for three months of exposure. A morphological analysis revealed non-significant toxic effects on the seedlings’ height, leaf area, and stem diameter among the genotypes and tested doses. The results of the atomic absorption analysis of the treatment with 4 g of γ-Fe2O3 NPs showed a concentration of 0.10 mg kg−1 of Cd2+, a limit lower than the control and the recommended value by the 2014 EU regulation. Thus, the transport and/or absorption of the Cd2+ toxic metal were significantly inhibited, since up to 74 % of Cd2+ uptake in the genotype ICS 95 was experimentally observed. Also, the environmental Fe-dynamics in the seedlings and soils demonstrated no transport of γ-Fe2O3 NPs to the seedlings. Thus, the study found that the Cd2+ adsorption in remediated soil using γ-Fe2O3 NPs involves three steps: electrostatic exchange, Fe-oxide adsorption, and substrate-γ-Fe2O3 NPs complexation and precipitation.