Research Center for Analytical Sciences, Chemistry Department, College of Sciences, Northeastern University, Shenyang, 110819, China.
Research Center for Analytical Sciences, Chemistry Department, College of Sciences, Northeastern University, Shenyang, 110819, China.
Talanta. 2020 Apr 1;210:120635. doi: 10.1016/j.talanta.2019.120635. Epub 2019 Dec 10.
In this work, a paper-based analytical device (PAD) for sensitive speciation detection of chromium (Cr) by smartphone camera was introduced. In anion electrokinetic stacking mode, Cr (VI) in the form of CrO4 was firstly enriched into a narrow band on a paper fluidic channel, and then the band was visualized by 1,5-diphenylcarbazide (DPC). Colorimetric detection of Cr (VI) was based on the gray intensity of stacking bands. Detection of Cr (III) was achieved by subtraction of the detection results of Cr (VI) before and after the sample was oxidized. Under optimized conditions, the detection limit of Cr (VI) and Cr (III) of 0.20 μM (10.4 μg L) and 0.30 μM (14.6 μg L) were achieved with a linear response in the range of 0.67-5.00 μM and 0.93-6.00 μM, respectively. The detection performance of PAD is close to that obtained by desktop spectrophotometry, thanks to the online stacking effect. Meanwhile, this PAD also exhibited a good selectivity over coexisting cations and anions, thanks to the charge selectivity of the stacking mode and the selective visualization reaction of DPC. Speciation detection of Cr from tap water, river water, surface water, and electroplating wastewater was demonstrated. This work shows the potential of PADs for on-site detection of Cr (VI) in environmental water samples.
本文介绍了一种基于纸质的分析装置（PAD），可通过智能手机摄像头实现对铬（Cr）的形态灵敏检测。在阴离子电动堆积模式下，Cr（VI）以 CrO4 的形式首先被富集到纸流道上的一个窄带中，然后通过 1,5-二苯基卡巴肼（DPC）显色。Cr（VI）的比色检测基于堆积带的灰度强度。Cr（III）的检测是通过在样品氧化前后检测 Cr（VI）的检测结果相减来实现的。在优化条件下，Cr（VI）和 Cr（III）的检测限分别为 0.20 μM（10.4 μg L）和 0.30 μM（14.6 μg L），线性响应范围分别为 0.67-5.00 μM 和 0.93-6.00 μM。得益于在线堆积效应，PAD 的检测性能接近台式分光光度法的检测性能。同时，由于堆积模式的电荷选择性和 DPC 的选择性显色反应，该 PAD 对共存的阳离子和阴离子也表现出良好的选择性。从自来水、河水、地表水和电镀废水中对 Cr 的形态检测进行了演示。这项工作展示了 PAD 在现场检测环境水样中 Cr（VI）的潜力。
