LAUSR

Abstract In this study, Fe 3 O 4 nanoparticles (NPs) loaded onto SBA-15-HESI (SBA-15-HESI-Fe 3 O 4 -NPs) as a novel sorbent was prepared and subsequently was applied for dispersive solid phase magnetic extraction (MSPME) and preconcentration of La (III) ions in water samples by ICP-OES. The synthesized sorbent was characterized by FT-IR, SEM, TEM, BET, VSM, BJH and XRD techniques. The important variables such as concentration of solvent, volume of extraction solvent, desorption time, pH of the sample soloution, initial concentration of La(III) ions, sorbents dosage and adsorption time were investigated and optimized by central composite design (CCD) combined with desirability function (DF). The optimum condition, concluded from one at a time method was 2 mL of 0.1 mol L −1 HCl as extraction solvent and 5.0 min from desorption time. Linear calibration range 20–200 and 10–220 μg L −1 , detection limit 0.21 and 0.16 μg L −1 , the relative standard deviations (RSD%) of 3 and 2% were obtained for SBA-15-HESI and SBA-15-HESI-Fe 3 O 4 -NPs, respectively. The enrichment factor 7.6 and 9.8, the preconcentration factor 7.37 and 9.43, the adsorption capacity 1.27 and 2.81 mg g −1 were obtained for SBA-15-HESI and SBA-15-Fe 3 O 4 -NPs, respectively.