Simultaneous determination of arsenic and cadmium by hydride generation atomic fluorescence spectrometry using magnetic zero-valent iron nanoparticles for separation and pre-concentration

Abstract

A novel method was established for simultaneous determination of trace arsenic and cadmium by hydride generation atomic fluorescence spectrometry (HG-AFS) using nanoparticles of zero-valent iron (nZVI) for separation and pre-concentration. As (III) and Cd (II) were selectively adsorbed by nZVI and easily separated from the sample matrix by a magnet. The nZVI was then completely dissolved in hydrochloric acid prior to determination of As(III) and Cd(II) by double-channel HG-AFS. Under the optimum conditions, the detection limits of As (III) and Cd(II) were 0.002 and 0.0008ng mL−1, which were improved 40 and 38 folds compared to the conventional method, respectively. The relative standard deviations (RSDs) for 1ng mL−1 As (III) and Cd (II) were better than 2.0% (n=7). The accuracy of the proposed method was validated by analyzing two certified reference samples, five water samples and two cell samples with satisfactory analytical results. The proposed method retains several unique advantages, including high sensitivity, simplicity and minimized interfere.