A novel nanomagnetic task specific ionic liquid as a selective sorbent for the trace determination of cadmium in water and fruit samples.

A selective sorbent was prepared for the simultaneous separation and preconcentration of cadmium ion from water and fruit samples, prior to determination by flame atomic absorption spectrometry (FAAS). The sorbent was synthesized by combining of Fe3O4 magnetic nanoparticles (MNPs) and Aliquat(®)336 thiosalicylate, [A336][TS], a thiol-containing task specific ionic liquid (TSIL). The high affinity of TSIL toward the target compound as well as the magnetic behavior of Fe3O4 was combined to provide an efficient and simple magnetic sorbent for solid-phase extraction (SPE). The prepared nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and vibrating sample magnetometer (VSM). The important parameters influencing the extraction efficiency such as pH, sorbent dosage, extraction and desorption conditions were studied and optimized. Under the optimum conditions, the calibration curve was linear in the range of 2.5-260 ng mL(-1) and good linearity (R(2)>0.996) was obtained. The limit of detection (LOD) and enrichment factor (EF) of the method were found to be 0.5 ng mL(-1) and 50, respectively. The relative standard deviations (RSDs %) were less than 3.1 (n=6) for the target analyte. In this method, only small amounts (20mg) of adsorbent were needed to obtain satisfactory extraction recoveries within 20 min. Finally, the proposed method was successfully applied for the trace determination of cadmium ions in fruit (apple, orange and banana) and water samples. Good spike recoveries, varied within the range of 95-109%, confirmed the good performance of the method in real sample analysis.