Fan Hong-Tao, Lu Yan, Liu Ai-Juan, Jiang Bing, Shen Hua, Huang Cong-Cong, Li Wen-Xiu
Liaoning Provincial Key Laboratory of Chemical Separation Technology, Shenyang University of Chemical Technology, Shenyang, 100142, Liaoning, China.
Liaoning Provincial Key Laboratory of Chemical Separation Technology, Shenyang University of Chemical Technology, Shenyang, 100142, Liaoning, China.
Anal Chim Acta. 2015 Oct 15;897:24-33. doi: 10.1016/j.aca.2015.09.056. Epub 2015 Oct 9.
A diffusive gradients in thin films (DGT) device for the analysis of free Cd(II) species, based on Cd(II) ion-imprinted sorbent (IIS) as the binding agents and commercial polyethersulfone membrane (PES) as diffusion layer, was developed (PES/IIS-DGT). DGT time-series experiments showed that the mass of free Cd(II) species accumulated by PES/IIS-DGT was linear vs. time (R(2) = 0.9953) and the concentration of free Cd(II) species by PES/IIS-DGT was in good agreement with the total dissolved concentrations of free Cd(II) species in simple synthetic solutions where free ionic species dominated. PES/IIS-DGT performance was independent in the range of pH 4.5-7.5 and ionic strength range from 1.0 × 10(-3) to 0.7 mol L(-1). The measurement of free Cd(II) species in synthetic solution containing different concentrations of ligands by PES/IIS-DGT showed an excellent agreement with the value measured by Cd(II) ion selective electrodes (Cd-ISE), indicating that PES/IIS-DGT method is more suitable than Cd-ISE for the measurement of low concentration of free Cd(II) species due to the enrichment of IIS for the analytes.
基于镉（II）离子印迹吸附剂（IIS）作为结合剂和商用聚醚砜膜（PES）作为扩散层，开发了一种用于分析游离镉（II）物种的薄膜扩散梯度（DGT）装置（PES/IIS-DGT）。DGT时间序列实验表明，PES/IIS-DGT积累的游离镉（II）物种质量与时间呈线性关系（R² = 0.9953），且在以游离离子物种为主的简单合成溶液中，PES/IIS-DGT测得的游离镉（II）物种浓度与游离镉（II）物种的总溶解浓度高度一致。PES/IIS-DGT的性能在pH 4.5 - 7.5范围内以及离子强度范围为1.0×10⁻³至0.7 mol·L⁻¹时不受影响。通过PES/IIS-DGT对含有不同浓度配体的合成溶液中游离镉（II）物种的测量结果与镉（II）离子选择性电极（Cd-ISE）测得的值高度吻合，这表明由于IIS对分析物的富集作用，PES/IIS-DGT方法比Cd-ISE更适合测量低浓度的游离镉（II）物种。
