Magnetic Solid-Phase Extraction of Lawsone Using Polyphenol-Coated Magnetic Nanoparticles: Synthesis, Characterization and examination

A novel polyphenol-coated CoFe2O4 system with sorption capacity of lawsone was synthesized as a magnetic sorbent by chemical oxidative polymerization process for magnetic solid-phase extraction of lawsone. The synthesized nanosorbent showed a spherical morphology with diameters under 50 nm by scanning electron microscopy images. The extraction efficiency of this sorbent was studied toward the extraction of lawsone from saline aqueous solution in dispersion mode. Major parameters including the type and volume of desorption solvent, amount of sorbent, desorption time, extraction time, extraction temperature, ionic strength, and pH were optimized. Under the optimum conditions, the relative standard deviation in 0.005 mu g mL(-1) (inter-day n = 6; intra-day: n = 6; and sorbent to sorbent n = 4) were obtained as 5.2, 8.07, and 11.7%, respectively. A linear calibration curve in the range of 0.003-0.5 mu g mL(-1) with R-2 = 0.993 was obtained. The limit of detection and limit of quantification of the method were 0.001 mu g mL(-1) and 0.003 mu g mL(-1), respectively. The relative recovery percentages were in range of 90-96.4% for henna leaves, henna shampoo, and henna dermal lotion real samples.