Separation and determination of cadmium in water by foam column prior to inductively coupled plasma optical emission spectrometry

The sorption profile of cadmium (II) ions from aqueous iodide media onto procaine hydrochloride (PQ+·Cl−) treated polyurethane foams (PUFs) solid sorbent was studied. PQ+·Cl− treated PUFs solid sorbent was found suitable and fast for Cd2+ uptake as [CdI4]aq2−. Thus, removal of Cd2+ at trace levels by the sorbent packed columns was achieved. The sorbed Cd2+ species onto packed column were recovered with HNO3 (10.0 mL, 1.0 mol L−1) prior determination by inductively coupled plasma-optical emission spectrometry (ICP-OES). Plot of Cd2+ ions concentration was linear in the range 0.05–15 μg L−1. The limits of detection and quantification of Cd2+ were found 0.01 μg L−1 and 0.033 μg L−1, respectively. Such limits could be improved to lower values by retention of Cd2+ species from large sample volumes of the aqueous phase at the optimized conditions. The relative standard deviation of the packed column for the extraction and recovery of standard aqueous solutions (0.1 L) containing 1.0 and 5.0 μg L−1 (n = 3) of Cd2+ ions at flow rate of 5.0 mL min−1 were 1.98 and 2.9%, respectively. The method was validated by analysis of Cd in certified reference materials (CRMs) IAEA-Soil-7 and TMDW water and wastewater samples.