Abstract:
This paper presents the development of cheap and selective Paper-based Analytical Devices (PADs) for selective Pd(II) determination from very acidic aqueous solutions. The PADs were obtained by impregnating two cm-side squares of filter paper with an azoic ligand, (2-(tetrazolylazo)-1,8 dihydroxy naphthalene-3,6,-disulphonic acid), termed TazoC. The so-obtained orange TazoC-PADs interact quickly with Pd(II) in aqueous solutions by forming a complex purple-blue-colored already at pH lower than 2. The dye complexes no other metal ions at such an acidic media, making TazoC-PADs highly selective to Pd(II) detection. Besides, at higher pH values, other cations, for example, Cu(II) and Ni(II), can interact with TazoC through the formation of stable and pink-magenta-colored complexes; however, it is possible to quantify Pd(II) in the presence of other cations using a multivariate approach. To this end, UV-vis spectra of the TazoC-PADs after equilibration with the metal ions solutions were registered in the 300-800 nm wavelength range. By applying Partial Least Square regression (PLS), the whole UV-vis spectra of the TazoC-PADs were related to the Pd(II) concentrations both when present alone in solution and also in the presence of Cu(II) and Ni(II). Tailored PLS models obtained with matrix-matched standard solutions correctly predicted Pd(II) concentrations in unknown samples and tap water spiked with the metal cation, making the method promising for quick and economical sensing of Pd(II).
摘要:
本文介绍了廉价且选择性的纸基分析设备(PAD)的开发,用于从非常酸性的水溶液中选择性测定Pd(II)。PAD是通过用偶氮配体浸渍两个厘米边的正方形滤纸获得的,(2-(四唑偶氮)-1,8二羟基萘-3,6,-二磺酸),称为TazoC。如此获得的橙色TazoC-PAD通过在低于2的pH下形成复杂的紫蓝色而与水溶液中的Pd(II)快速相互作用。染料在这样的酸性介质上不配合其他金属离子,使TazoC-PAD对Pd(II)检测具有高度选择性。此外,在较高的pH值,其他阳离子,例如,Cu(II)和Ni(II),可以通过形成稳定的粉红色洋红色复合物与TazoC相互作用;然而,可以使用多变量方法在其他阳离子存在下量化Pd(II)。为此,在300-800nm波长范围内记录与金属离子溶液平衡后的TazoC-PAD的UV-vis光谱。通过应用偏最小二乘回归(PLS),当单独存在于溶液中以及存在Cu(II)和Ni(II)时,TazoC-PAD的整个UV-vis光谱与Pd(II)浓度有关。用基质匹配的标准溶液获得的量身定制的PLS模型正确预测了未知样品和掺有金属阳离子的自来水中的Pd(II)浓度,该方法有望用于快速,经济地传感Pd(II)。