Determination of Cd and Pb ions in the animal feed of West Azarbaijan

In this research, a novel method based on solid phase extraction (SPE) combined with atomic absorption spectroscopy (AAS) is provided. Since, the concentration of heavy metals in concentrated animal feeding is low, thus the direct determination of these elements is not possible especially after preparation of aqueous samples. Therefore, magnetic iron oxide nanoparticles (Fe3O4 NPs) have been used for preconcentration and extraction of the analytes prior to determination with AAS after desorption of them in aqueous media. Various parameters such as salt effect, the amount of sorbent, Exposure time, desorption conditions (desorption solvent and time) and sorbent concentration were optimized. Under the optimum conditions (pH=7 , 0.1 g sorbent, salt concentration (1M) and 5 min exposure time) both of the cations were extracted from 50 mL sample solution (1 μg mL-1) and then were desorbed using nitric acid (2 mL, 0.5 M). The proposed technique was linear in the range of (0.03-30 μg mL-1) and the LOD was estimated equal with 30 ppb. Finally the proposed method was successfully applied for determination of Pb2+ and Cd2+ in concentrated animal feed samples of West Azarbaijan [1].