Applying Al_2O_3@Ag@trithiocyanuric acid as an efficient metal ion scavenger for the selective extraction of iron (Ⅲ) and lead (Ⅱ) from environmental waters

摘要

In the present study, silver (Ag) atoms were chemically deposited on gamma-alumina (Al2O3) nanospheres to be further functionalized with trithiocyanuric acid (TTC). The result was Al2O3@Ag@TTC composites, which were used for the selective extraction and preconcentration of Fe (III) and Pb (II) ions in seawater and river water samples. TTC is a potent scavenger of heavy metal ions with multiple nitrogenand sulfur-containing functional groups. The concentrations of analytes were determined by flame atomic absorption spectrometry, and the structure of the synthetic adsorbent was characterized by spectral and microscopic techniques. Furthermore, the fundamental parameters influencing the extraction and desorption of the target ions were evaluated. Under optimized conditions, the calibration curve was linear in the range of 10-100 ng mL(-1) for both analytes. The detection limits of the proposed method for Fe (III) and Pb (II) ions were 1.5 ng mL-1 and 0.8 ng mL(-1), respectively, with a relative standard deviation of less than 6.1% (n = 7). Moreover, the proposed method tolerated salinities of up to 50.0 g L-1 without exhibiting any decrease in selectivity or recovery. The developed method was successfully applied to extract Fe (III) and Pb (II) ions from seawater and river water samples. The extraction recovery rates of the spiked ions were at least 93% for Fe (III) and 97 % for Pb (II).