LAUSR

In this research, a novel, simple, sensitive and selective method has been presented for the determination of iron using dissolvable bathocuproine disulfonic acid (BCS)-layered double hydroxides (LDHs) for dispersive solid-phase extraction (DSPE). Bathocuproine disulfonic acid (BCS)-intercalated MgAl-LDH nanosheets were successfully synthesized by a co-precipitation method. This was followed by an anion-exchange treatment. The extraction and colorimetric detection were based on the selective interaction of BCS-intercalated MgAl-LDH nanosheets with iron(II) and its color change. The color of BCS–iron(II)–MgAl-LDH could be easily observed with the naked eye, as it dissolved in acid to release the colored complex of iron(II), which was then directly introduced into a UV-vis spectrophotometer for analysis. The key parameters of the extraction were examined and optimized via a colorimetric method. Under the optimum conditions, a linear range of 0.5–100 μg L−1 was obtained with a good correlation coefficient of r2 = 0.9972 and a limit of detection of 0.4 μg L−1. The inter-day and intra-day relative standard deviations (RSDs) for six replicate determinations after the extraction of 50 μg L−1 were 2.9% and 4.1% respectively. The successful application of the proposed method was shown for the determination of iron in beverage and water samples.