Trace Analysis of Heavy Metals (Cd, Pb, Hg) Using Native and Modified 3D Printed Graphene/Poly(Lactic Acid) Composite Electrodes,Electroanalysis

当前位置： X-MOL 学术 › Electroanalysis › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Trace Analysis of Heavy Metals (Cd, Pb, Hg) Using Native and Modified 3D Printed Graphene/Poly(Lactic Acid) Composite Electrodes
Electroanalysis ( IF 2.7 ) Pub Date : 2020-02-12 , DOI: 10.1002/elan.201900658
John G. Walters ₁ , Shakir Ahmed ₁ , Irina M. Terrero Rodríguez ₁ , Glen D. O'Neil ₁

Affiliation

Here we investigate the use of 3D printed graphene/poly(lactic acid) (PLA) electrodes for quantifying trace amounts of Hg, Pb, and Cd. We prepared cylindrical electrodes by sealing a 600 μm diameter graphene/PLA filament in a pipette tip filled with epoxy. We characterized the electrodes using scanning electron microscopy, Raman spectroscopy, and cyclic voltammetry in ferrocene methanol. The physical characterization showed a significant amount of disorder in the carbon structure and the electrochemical characterization showed quasi‐reversible behavior without any electrode pretreatment. We then used unmodified graphene/PLA electrode to quantify Hg, and Pb and Cd in 0.01 M HCl and 0.1 M acetate buffer using square wave anodic stripping voltammetry. We were able to quantify Hg with a limit of detection (LOD) of 6.1 nM (1.2 ppb), but Pb and Cd did not present measurable peaks at concentrations below ∼400 nM. We improved the LODs for Pb and Cd by depositing Bi microparticles on the graphene/PLA and, after optimization, achieved clear stripping peaks at the 20 nM level for both ions (4.1 and 2.2 ppb for Pb²⁺ and Cd²⁺, respectively). The results obtained for all three metals allowed quantification below the US Environmental Protection Agency action limits in drinking water.

中文翻译：

使用原生和修饰的3D打印石墨烯/聚乳酸复合电极对痕量重金属（Cd，Pb，Hg）进行痕量分析

在这里，我们研究了使用3D打印的石墨烯/聚乳酸（PLA）电极来量化痕量的Hg，Pb和Cd。我们通过在充满环氧树脂的移液器吸头中密封直径为600μm的石墨烯/ PLA灯丝来制备圆柱形电极。我们在二茂铁甲醇中使用扫描电子显微镜，拉曼光谱和循环伏安法对电极进行了表征。物理表征显示出大量的碳结构无序，而电化学表征则显示了可逆行为，无需任何电极预处理。然后，我们使用未经修饰的石墨烯/ PLA电极，使用方波阳极溶出伏安法在0.01 M HCl和0.1 M乙酸盐缓冲液中对Hg，Pb和Cd进行定量。我们能够以6.1 nM（1.2 ppb）的检出限（LOD）对Hg进行定量，但是在低于约400 nM的浓度下，Pb和Cd没有出现可测量的峰。通过将Bi微粒沉积在石墨烯/ PLA上，我们改善了Pb和Cd的LOD，优化后，两种离子在20 nM的水平上均获得了清晰的溶出峰（Pb的4.1和2.2 ppb²⁺和Cd ²⁺）。对所有三种金属获得的结果均可以定量，其浓度低于美国环境保护局在饮用水中的限量。

更新日期：2020-02-12

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11