Preparation of a chitosan-coated C18-functionalized magnetite nanoparticle sorbent for extraction of phthalate ester compounds from environmental water samples

Abstract

Novel superparamagnetic chitosan-coated C 18 -functionalized magnetite nanoparticles (MNPs) were successfully synthesized and applied as an effective sorbent for the preconcentration of several typical phthalate ester compounds from environmental water samples. The MNPs were 20 nm in diameter and had a high magnetic saturation value (52 emu g −1 ), which endowed the sorbent with a large surface area and the convenience of isolation from water samples. Phthalate esters could be extracted by the interior octadecyl groups through hydrophobic interaction. The hydrophilic porous chitosan polymer coating promoted the dispersion of MNPs in water samples, and improved the anti-interference ability of the sorbent without influencing the adsorption of analytes. The main factors affecting the adsorption of phthalate esters, including the pH of the solution, humic acid, sample loading volume, adsorption time, and desorption conditions, were investigated and optimized. Under the conditions selected (pH 11, adsorption time 20 min, elution with 10 mL of acetonitrile, and concentration to 0.5 mL), concentration factors of 1,000were achieved by extracting 500 mL of several environmental water samples with 0.1 g of MNP sorbent. The method detection limits obtained for di-n-propyl phthalate, di-n-butyl phthalate, dicyclohexyl phthalate, and di-n-octyl phthalate were 12.3, 18.7, 36.4, and 15.6 ng L −1 , respectively. The recoveries of spiked samples ranged from 60 to 100%, with a low relative standard deviation (1-8%), which indicated good method precision.

Magnetic nanoparticles with hydrophobicity and hydrophilicity for solid-phase extraction of polycyclic aromatic hydrocarbons from environmental water samples

“…For example, MNPs functionalized with C 18 , C 8 and cyclodextrin were applied for the extraction of organophosphorous pesticides [9], peptides [10] and biphenolic pollutants [11], respectively. However, the functionalized MNPs are usually difficult to disperse well in aqueous sample owing to their high hydrophobicity, especially for the particles below 50 nm [12]. On the other hand, these MNPs aggregate easily, which may decrease their stability and be detrimental to the extraction performance [13].…”

“…For these reasons, a hydrophilic layer constructed on the surface of hydrophobic MNPs is essential to improve the aqueous dispersibility, and thus enhance the Page 4 of 36 A c c e p t e d M a n u s c r i p extraction reproducibility and operation convenience. As a typical example, Cai et al synthesized a novel MNP sorbent with an interior C 18 group and an exterior chitosan polymer coating, to extract perfluorinated and phthalate ester compounds from environmental water samples [12].…”

Extraction of Phthalate Esters in Environmental Water Samples Using Layered-Carbon Magnetic Hybrid Material as Adsorbent Followed by Their Determination with HPLC

“…Therefore, it 39 and chitosan-coated C18-functionalized magnetite nanoparticle, 40 had been used for the MSPE of some PAEs in water and beverage samples with excellent results. Compared with the reported MSPE methods, less time was needed for the current process, which indicated a high extraction efficiency of the LC-based magnetic nanocomposite for the PAEs.…”

Mixed-Hemimicelle Solid Phase Extraction Followed by Dispersive Liquid-Liquid Microextraction of Amphetamines from Biological Samples

“…40,41 ) at 80 ºC under nitrogen atmosphere while stirring in three necked round bottom. The black colloidal product was collected using a 1.4 T magnet and it was washed several times by degassed deionized water.…”