Separation and solid phase extraction method for the determination of cadmium in environmental samples

A solid phase extraction method was developed for the determination, preconcentration and separation of cadmium. The method is based on the adsorption of cadmium as 4-(2-pyridylazo) resorcinol (PAR) complex on Duolite XAD-761 resin. The extracted cadmium was determined by Flame Atomic Absorption Spectrometry (FAAS). The optimum experimental conditions for the cadmium assay were investigated. The optimum pH value for quantitative sorption of Cd-PAR was found between 3.5 and 5.5. Elution process was performed by using 5 mL of ethanol–2 mol L− 1 HNO3 mixtures (1:3 v/v). The preconcentration factor was found as 160 for 800 mL aqueous solution containing 2.5 μg Cd. In optimized conditions, the detection limit for cadmium was found to be 0.38 μg L− 1. The method was applied to the determination of cadmium in different water samples.