Bentonite-modified glassy carbon electrode for the voltammetric determination of caffeine in beverages

IF 8.5 1区农林科学 Q1 CHEMISTRY, APPLIED

Food Chemistry Pub Date : 2025-06-26 DOI:10.1016/j.foodchem.2025.145306

Nathalia Oliveira Soares, Débora Marina Bittencourt Goldner, Jorge C. Masini

{"title":"Bentonite-modified glassy carbon electrode for the voltammetric determination of caffeine in beverages","authors":"Nathalia Oliveira Soares, Débora Marina Bittencourt Goldner, Jorge C. Masini","doi":"10.1016/j.foodchem.2025.145306","DOIUrl":null,"url":null,"abstract":"<div><div>This study introduces a glassy carbon electrode modified with Na<sup>+</sup>-exchanged bentonite and Nafion for caffeine determination in beverages using differential pulse voltammetry. Bentonite, a high-surface-area clay, enhances caffeine adsorption, while Nafion stabilizes the clay layer and improves interaction through hydrogen bonding and electrostatic mechanisms. The modification is fast and cost-effective. The electrode demonstrated a linear range of 0.25–4.0 μM, with detection and quantification limits of 0.076 μM and 0.25 μM—five times lower than an unmodified electrode. Caffeine metabolites like theobromine and paraxanthine had minimal interference due to the clay's selective affinity. Results from instant coffee, energy drinks, cola, and green tea matched HPLC-UV within 5 %, confirming accuracy. However, caffeine in yerba mate was 30 % higher, likely due to theobromine interference. This method offers a low-cost, highly sensitive alternative for caffeine determination, improving selectivity over conventional electroanalytical approaches.</div></div>","PeriodicalId":318,"journal":{"name":"Food Chemistry","volume":"492 ","pages":"Article 145306"},"PeriodicalIF":8.5000,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Food Chemistry","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0308814625025579","RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, APPLIED","Score":null,"Total":0}

引用次数: 0

Abstract

This study introduces a glassy carbon electrode modified with Na⁺-exchanged bentonite and Nafion for caffeine determination in beverages using differential pulse voltammetry. Bentonite, a high-surface-area clay, enhances caffeine adsorption, while Nafion stabilizes the clay layer and improves interaction through hydrogen bonding and electrostatic mechanisms. The modification is fast and cost-effective. The electrode demonstrated a linear range of 0.25–4.0 μM, with detection and quantification limits of 0.076 μM and 0.25 μM—five times lower than an unmodified electrode. Caffeine metabolites like theobromine and paraxanthine had minimal interference due to the clay's selective affinity. Results from instant coffee, energy drinks, cola, and green tea matched HPLC-UV within 5 %, confirming accuracy. However, caffeine in yerba mate was 30 % higher, likely due to theobromine interference. This method offers a low-cost, highly sensitive alternative for caffeine determination, improving selectivity over conventional electroanalytical approaches.

Abstract Image

查看原文本刊更多论文

膨润土改性玻碳电极伏安法测定饮料中咖啡因

介绍了一种用Na+交换膨润土和Nafion修饰的玻碳电极，用于差动脉冲伏安法测定饮料中的咖啡因。膨润土是一种高表面积的粘土，可以增强咖啡因的吸附，而Nafion则可以稳定粘土层，并通过氢键和静电机制改善相互作用。这种改造既快速又划算。电极的线性范围为0.25 ~ 4.0 μM，检测限和定量限分别为0.076 μM和0.25 μM，比未修饰电极低5倍。由于黏土的选择性亲和性，咖啡因代谢物如可可碱和副黄嘌呤的干扰最小。速溶咖啡、能量饮料、可乐、绿茶的检测结果与HPLC-UV的匹配度在5 %以内，准确度较高。然而，马黛茶中的咖啡因含量高出30% %，可能是由于可可碱的干扰。该方法为咖啡因分析提供了一种低成本，高灵敏度的替代方法，提高了传统电分析方法的选择性。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Food Chemistry 工程技术-食品科技

CiteScore

16.30

自引率

10.20%

发文量

3130

审稿时长

122 days

期刊介绍： Food Chemistry publishes original research papers dealing with the advancement of the chemistry and biochemistry of foods or the analytical methods/ approach used. All papers should focus on the novelty of the research carried out.