5-(p-Dimethylaminobenzylidene) rhodanine-modified magnetic halloysite nanotubes as a new solid phase sorbent for silver ions

Abstract

In this work, magnetic halloysite nanotubes (MHNTs) were modified with 5-(p-dimethylaminobenzylidene) rhodanine by using a facile procedure and the modified MHNTs were used as a new and inexpensive magnetic solid phase extraction sorbent for the separation and preconcentration of Ag(I) ions from environmental samples. The factors affecting the adsorption of μg L⁻¹ levels of silver onto the sorbent were investigated. Quantitative recoveries (>95%) were obtained for acidic solution (pH = 3) using 0.05 g of sorbent. Under the optimum conditions, the calibration graph was linear in the 4.0–200 μg L⁻¹ concentration range, with a detection limit of 1.6 μg L⁻¹. The selectivity of the method was studied and no serious interference was observed. This method was applied for the determination of trace silver in various water and soil samples.