Cadmium ion-selective sorbent preconcentration method using ion imprinted poly(ethylene glycol dimethacrylate-co-vinylimidazole)

The present study focuses on the preparation of an Cd2+-imprinted poly(ethylene glycol dimethacrylate-co-vinylimidazole) for selective extraction/preconcentration of Cd2+ ions from aqueous solution, with further determination by FAAS using a flow system. Sorbent extraction/preconcentration system was optimized by using chemometric tools (factorial design and Doehlert matrix). Under optimized conditions, the method presented a limit of detection of 0.11 μg L−1 and linear analytical curve from 1.0 up to 50.0 μg L−1 (r = 0.993). The preconcentration factor (PF), consumptive index (CI) and concentration efficiency (CE) were found to be 38.4, 0.39 mL and 14.3 min−1, respectively. The selectivity coefficient of ion imprinted polymer was compared with the selectivity coefficient of NIP (non-imprinted polymer) for the Cd2+/Pb2+, Cd2+/Cu2+ and Cd2+/Zn2+ binary mixtures, where the respective values of relative selectivity coefficient (k′) of 157.5, 4.44 and 1.38 were obtained. The proposed method was successfully applied for cadmium determination in different types of water samples, urine and certified reference material (Lobster Hepatopancreas).