Stripping analysis of Pb(II), Cd(II), Hg(II) and Cu(II) based on irradiated attapulgite/Ionic liquid composites.

The individually and simultaneously detection of heavy metal ions have been widely reported. However, little analyzed the difference and relationship between the two such as sensitivities and limit of detection (LOD) using irradiated natural materials. Based on the electrochemical detection of Pb(II), Cd(II), Hg(II) and Cu(II) ions, their stripping behaviors, through combining an irradiated attapulgite (IAP) at a fluence of 30 kGy (IAP30) with room temperature ionic liquid (RTIL) composites coated electrodes, were compared and analyzed by square wave stripping voltammetry. The characteristic of sensitivities and LOD of IAP30/RTIL electrode towards metal ions were markedly improved in comparison with IAP electrode. The LOD of the simultaneous detection towards Pb(II), Cd(II), Cu(II) and Hg(II) using IAP30/RTIL electrode were 0.8, 0.5, 0.2 and 0.06 nM, respectively. The sensitivities and LOD of Pb(II), Cd(II) in simultaneous detection were lower and higher than these in individual detection, while those of Hg(II) and Cu(II) increased and decreased in comparison with the individual detection at IAP30/RTIL or IAP30 modified electrode. An enhanced sensitivity of Hg(II) in the simultaneous detection reached 242.4 μA/μM, and was the largest among four metal ions. Analysis of six groups of solutions including Pb(II)-Cd(II)-Hg(II), Cd(II)-Cu(II)-Hg(II), Pb(II)-Cu(II)-Hg(II), Cu(II)-Hg(II), Pb(II)-Hg(II), Cd(II)-Hg(II) were further performed, respectively. This study provided a novel method for the construction of sensitive electrochemical sensors of heavy metal by natural materials, and an effective reference that meet the needs of environmental control for analysis of different metal ions. [ABSTRACT FROM AUTHOR]