School of Chemistry, The University of Melbourne, Parkville, VIC, 3010, Australia.
Mikrochim Acta. 2022 Jun 3;189(7):243. doi: 10.1007/s00604-022-05339-w.
The development of the first microfluidic paper-based analytical device (µPAD) for the speciation of inorganic arsenic in environmental aqueous samples as arsenite (As(III)) and arsenate (As(V)) which implements hydride generation on a paper platform is described. The newly developed µPAD has a 3D configuration and uses Au(III) chloride as the detection reagent. Sodium borohydride is used to generate arsine in the device's sample zone by reducing As(III) in the presence of hydrochloric acid or both As(III) and As(V) (total inorganic As) in the presence of sulfuric acid. Arsine then diffuses across a hydrophobic porous polytetrafluoroethylene membrane into the device's detection zone where it reduces Au(III) to Au nanoparticles. This results in a color change which can be related to the concentration of As(III) or total inorganic As (i.e., As(III) and As(V)) concentration. Under optimal conditions, the µPAD is characterized by a limit of detection of 0.43 mg L for total inorganic As (As(III) + As(V)) and 0.41 mg L for As(III) and a linear calibration range in both cases of 1.2-8.0 mg As L. The newly developed µPAD-based method was validated by applying it to groundwater and freshwater samples and comparing the results with those obtained by conventional atomic spectrometric techniques.
描述了一种用于环境水样中无机砷形态分析（亚砷酸盐 (As(III)) 和砷酸盐 (As(V))）的第一台基于微流控纸的分析装置 (µPAD) 的开发，该装置在纸平台上实现了氢化物发生。新开发的 µPAD 具有 3D 结构，并使用三氯化金 (Au(III)) 作为检测试剂。硼氢化钠在盐酸存在下将 As(III) 还原为 Arsine，或者在硫酸存在下同时将 As(III) 和 As(V)（总无机砷）还原为 Arsine。Arsine 然后扩散穿过疏水多孔聚四氟乙烯膜进入装置的检测区，在那里它将 Au(III) 还原为金纳米粒子。这导致颜色变化，可以与 As(III) 或总无机砷（即 As(III) 和 As(V)）浓度相关。在最佳条件下，µPAD 的检测限为 0.43 mg L 总无机砷（As(III) + As(V)）和 0.41 mg L As(III)，两种情况下的线性校准范围均为 1.2-8.0 mg As L。通过将新开发的基于 µPAD 的方法应用于地下水和淡水样品，并将结果与传统原子光谱技术获得的结果进行比较，对其进行了验证。
