Vortex assisted dispersive micro solid phase extraction using schiff base ligand anchored nano magnetic iron oxide for preconcentration of phthalate esters and determination by GC-FID

Nowadays, phthalate esters (PAEs) are widely used in production of polymer materials; therefore they occur in final products such as plastics, food packages and cosmetics. These compounds undergo emission into the environment and have a negative impact on living organisms [1]. In the present work, a novel nano sorbent was prepared via schiff base reaction between p-dimethylaminobenzaldehyde and Fe3O4@SiO2-NH2 nanoparticles [2]. The morphology and surface properties of the adsorbent was characterized using Fourier transform infrared spectroscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy. Modified nano sorbent was successfully applied for dispersive micro solid phase extraction and gas chromatography flame ionization detection (GC-FID) of six types of PAEs including Dimethyl phthalate (DMP), Diethyl phthalate (DEP), Di-n-butyl phthalate (DBP), Butylbenzyl phthalate (BBP), Bis-(2-ethylhexyl) phthalate (DEHP) and Di-n-octyl phthalate (DOP). Several variables affecting the extraction efficiency such as pH, amount of sorbent, extraction solvent type and volume, extraction and desorption time and salt effects were investigated and optimized. The best working conditions were as follows: amount of sorbent, 15 mg; type of solvent, n-Hexane; NaCl concentration, 10 % (w/v); sample volume, 25 ml; Vortex time for adsorbtion, 1.5 min; Sonicatetimefor desorption,2 min; pH, 8.1 . Under the optimal conditions the calibration curves were linear in the range of 1- 150µgL-1 for DMP, DEHP, DOP and 0.1-200 µgL-1for DEP, DBP, BBP. The limit of detections (S/N = 3) obtained in the range of 0.03-0.4µg L-1. Finally, the method was successfully applied for the preconcentration and determination of phthalate esters in bottled water, packaged yogurt and infusion serum with acceptable performance.