A method for measurement of free cadmium species in waters using diffusive gradients in thin films technique with an ion-imprinted sorbent
2015; Elsevier BV; Volume: 897; Linguagem: Inglês
10.1016/j.aca.2015.09.056
ISSN1873-4324
AutoresHong‐Tao Fan, Yan Lu, Aijuan Liu, Bing Jiang, Hua Shen, Congcong Huang, Wenxiu Li,
Tópico(s)Analytical Chemistry and Sensors
ResumoA 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 (R2 = 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.
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