Mesoporous Silica‐coated Magnetic Nanoparticles for Mixed Hemimicelles Solid‐phase Extraction of Phthalate Esters in Environmental Water Samples with Liquid Chromatographic Analysis

Abstract

To extract, preconcentrate and determine the trace level of environmental contaminants, a novel mixed hemimicelles solid-phase extraction (MHSPE) method based on mesoporous silica-coated magnetic nanoparticles (Fe 3 O 4 /meso-SiO 2 NPs) as adsorbent was developed for extraction of phthalate esters from water samples. The Fe 3 O 4 /meso-SiO 2 NPs were synthesized by using a combination of hydrothermal method and sol-gel method. The obtained Fe 3 O 4 /meso-SiO 2 NPs possessed a large surface area (570 m 2 /g), superparamagnetism, and uniform mesopores (2.8 nm). MHSPE parameters, such as the amount of surfactant, pH of sample, shaking and separation time, eluent and breakthrough volume that may influence the extraction of analytes greatly, were further investigated. Under the optimized conditions, the extraction was completed in 20 min and a concentration factor of 500 was achieved by extracting 250 mL water sample. Detection limits obtained of butyl-benzyl phthalate (BBP), di-n-butyl phthalate (DnBP), di-(2-ethylhexyl) phthalate (DEHP) and di-n-cotyl phthalate (DnOP) were 12, 21, 12, and 32 ng/L, respectively. The proposed method exhibited high extraction efficiency and relatively short time for extracting the target compounds.

Surfactant-modified flowerlike layered double hydroxide-coated magnetic nanoparticles for preconcentration of phthalate esters from environmental water samples

“…For this reason 25 mg of MLDH was chosen as the optimal amount for use in subsequent experiments. The optimal amounts of semimicelle/extracting agent used as the solid phase was less than that reported by other researchers [22,23,28,35,36]. In fact, the optimal amount of extracting agent determined in this study was 1/20 of that of the amount of Al 2 O 3 and SiO 2 particles modified by surfactant that was observed in previous studies [28].…”

Micelles as Soil and Water Decontamination Agents

“…Owing to the superparamagnetism, even mesopore size (2.8 nm), and larger surface area (570 m 2 /g) of the adsorbent, this method displayed excellent extraction efficiency for the removal of target phthalates, i.e., di-n-butyl phthalate, butylbenzyl phthalate, di-n-cotyl phthalate, and di(2-ethylhexyl) phthalate. 96 Moreover, the method detected 21, 12, 32, and 12 ng/L of the respective phthalates, respectively, and comparative studies showed improved results using different adsorbents. The work of Li and co-workers revealed thatmore effective adsorption of diethyl phthalate from water occurs over SDS-covered nanosized alumina compared to SDS-covered microsized alumina due to smaller size and enhanced surface-binding energy.…”

“…Liu and co-workers developed the MHSPE method with mesoporous silica-covered magnetic nanoparticles (Fe 3 O 4 /meso-SiO 2 NPs) as an adsorbent for the removal of phthalates from contaminated water samples. Owing to the superparamagnetism, even mesopore size (2.8 nm), and larger surface area (570 m 2 /g) of the adsorbent, this method displayed excellent extraction efficiency for the removal of target phthalates, i.e., di- n -butyl phthalate, butylbenzyl phthalate, di- n -cotyl phthalate, and di­(2-ethylhexyl) phthalate . Moreover, the method detected 21, 12, 32, and 12 ng/L of the respective phthalates, respectively, and comparative studies showed improved results using different adsorbents.…”

Nanomaterials for analysis and monitoring of emerging chemical pollutants

“…The analytes can be strongly adsorbed via multiple mechanisms: hydrophobic or chain-chain interactions with the hydrocarbon chains of the surfactant, or electrostatic interaction or hydrogen bonding with the polar groups, so this technique is particularly suitable for amphiphilic analytes or those bearing long alkyl chains {e.g., perfluorinated compounds (PFCs) [62], alkylphenols [62][63][64], and phthalate esters [65,66]}.…”