EXTRACTION OF PHTHALATES ESTER COMPOUNDS FROM ENVIRONMENTAL WATER SAMPLES WITH CHITOSAN COATED C18-FUNCTIONALIZED MAGNETIC NANOPARTICLES AS SORBENTS

摘要

A novel type of superparamagnetic chitosan-coated Fe3O4-C18 nanoparticle sorbents was successfully synthesized and applied as an effective sorbent material for the pre-concentration of several typical phthalates ester compounds from environmental water samples. The surface of magnetite (Fe3O4) was functionalized with octadecyl group (-C18) by silanization method, followed by the coating of chitosan-tripolyphosphate polymer on the Fe3O4-C18 magnetic nanoparticle (MNPs) by ionotropic gelation. The chitosan-coated Fe3O4-C18 MNPs were of uniform sizes in the range of 20–25 nm, and had a high magnetic saturation value of 62 emu g.1. The main factors affecting adsorption of phthalates ester compounds including pH of solution, sample loading volume, humic acid (HA), ionic strength were investigated and optimized. Under selected conditions, concentration factor of 1000 were achieved by SPE of 500 mL of several environmental water samples. The method detection limits obtained for Di-n-propyl-phthalate (DPP), di-n-butyl-phthalate (DBP), di-cyclohexyl-phthalate (DCP), di-n-octyl-phthalate (DOP) were 0.10, 0.28, 0.07, and 0.10 ng L-1, respectively. The relative standard deviation of recoveries ranged from 2 to 8 %, which indicated good method precision.