Synthesis and application of novel silver magnetic amino silicone adhesive particles for preparation of high purity α-linolenic acid from tree peony seed oil under applied magnetic field

Silver magnetic amino silicone adhesive (Fe 3 O 4 @SiO 2 @NH 2 @Ag) particles were prepared for the purification of α-linolenic acid from tree peony seed oil under applied magnetic field. First, Fe 3 O 4 @SiO 2 @NH 2 @Ag particles were prepared and physicochemically characterized, including XRD, TG, FTIR, SEM, magnetic hysteresis curves and elemental analysis. The static process for the purification of α-linolenic acid using Fe 3 O 4 @SiO 2 @NH 2 @Ag particles was investigated, including adsorption curve, desorption curve, elution solvent composition and adsorption isotherm. The result indicated that 0-1–4% acetone- n -hexane elution solvent was selected for the gradient elution process, 2 h and 60 min were the time required to reach adsorption and desorption equilibrium, 20 °C was selected as the adsorption temperature, Langmuir model was suitable to fit and explain the equilibrium data, and the adsorption process was spontaneous and exothermic. Under applied magnetic field, the dynamic process for the purification of α-linolenic acid using Fe 3 O 4 @SiO 2 @NH 2 @Ag particles was investigated, and the optimum conditions were 20:1 µL/g loading amount, 0.5 mL/min flow rate and 51.73 Oe magnetic field intensity. After purification, the purity and recovery ratio of α-linolenic acid were calculated to be 94% and 74%, respectively. Furthermore, the recycled Fe 3 O 4 @SiO 2 @NH 2 @Ag particles still achieved better purification result. Therefore, the developed method shows a good application prospect in the field of separation and purification of α-linolenic acid.