Phthalate Esters In Water Samples Research Articles

Quinoline Bridging Hyperconjugated Covalent Organic Framework as Solid-Phase Microextraction Coating for Ultrasensitive Determination of Phthalate Esters in Water Samples.

Phthalate esters (PAEs) are widely distributed in the environment, and this has caused serious health and safety concerns. Development of rapid and ultrasensitive identification and analysis methods for phthalate esters is urgent and highly desirable. In this work, a novel nitrogen-rich covalent organic framework (N-TTI) derived quinoline bridging covalent organic framework (N-QTTI) was fabricated and used as a solid-phase microextraction (SPME) coating for the ultrasensitive determination of phthalate esters in water samples. The physical and chemical properties of N-QTTI were investigated sufficiently. The N-QTTI-coated fiber demonstrates a superior enrichment performance than either the N-TTI-coated fiber or commercial fibers under the optimized SPME conditions. For the first time, we propose a semi-immersion strategy for the extraction of PAEs from water samples based on N-QTTI-coated SPME fibers. Combined with gas chromatography-mass spectrometry (GC-MS), the developed method N-QTTI-SPME-GC-MS exhibits a wide linear range with a satisfactory linearity (R2 ≥ 0.995). The limits of detection (LOD, S/N = 3) and the limits of quantification (LOQs, S/N = 10) were 0.17-1.70 and 0.57-5.60 ng L-1, respectively. The repeatability of the new method was examined using relative standard deviations (RSDs) between intraday and interday data, which were 0.38-7.98% and 1.22-6.60%, respectively. The spiked recoveries at three levels of 10, 100, and 1000 ng L-1 were in the range of 90.0-106.2% with RSDs of less than 7.48%. The enrichment factors ranged from 291 to 17180. When compared to previously published works, the LODs of the newly established method were improved 5-5400 times, and the enrichment factors were increased by at least 8 times. The absorption mechanism was investigated by X-ray photoelectron spectroscopy and noncovalent interaction force analysis. The technique was successfully employed for detecting PAEs in water samples.

Construction of hypercrosslinked polymers for high-performance solid phase microextraction of phthalate esters from water samples

Design and synthesis of novel coatings for solid phase microextraction (SPME) is urgently needed for sample pretreatment. In this study, three hypercrosslinked polymers (HCPs) were constructed by the facile Friedel-Crafts alkylation reactions between tetraphenylethylene (TPE) and 1,4-bis(chloromethyl)benzene (BCMB), 4,4′-bis(chloromethyl)-1,1′-biphenyl (BCMBP), and cyanuric chloride (CC), respectively. The newly-synthesized HCPs were employed as SPME coatings for the extraction of phthalate esters (PAEs). Various parameters influencing the SPME efficiencies, including extraction time and temperature, ionic strength, stirring rate, desorption temperature and time were optimized. Under the optimal conditions, low limits of detection (0.003–0.033 μg L − 1), wide linearity (0.01–10 μg L − 1) and good repeatability (4.1–9.3%) were achieved. The HCPs-based SPME method was successfully applied for the determination of eight PAEs in environmental water and bottled water samples with recoveries from 75.3% to 116%. This method provides a good alternative for monitoring trace level of PAEs in water samples.

Preparation of multi-walled carbon nanotubes based magnetic multi-template molecularly imprinted polymer for the adsorption of phthalate esters in water samples.

Taking the advantages of surface imprinting, multi-template imprinting and magnetic separation, a novel magnetic multi-template molecularly imprinted polymer (mag-MMIP@MWCNTs) was prepared by using MWCNTs as support material, Fe3O4 as magnetic core, and dimethyl phthalate (DMP), diethyl phthalate (DEP), and dibutyl phthalate (DBP) as template molecules. This composite was characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM), and the Brunauer-Emmett-Teller (BET) analysis, and was used for the simultaneous adsorption of DMP, DEP, and DBP in aqueous solution. The effects of solution pH, contact time, PAEs initial concentration, temperature, adsorption selectivity, and reusability were investigated and discussed in detail. The results demonstrated that mag-MMIP@MWCNTs exhibited fast kinetics, good magnetic separation, and excellent selectivity for the adsorption of three phthalate esters (PAEs). The adsorption kinetics followed pseudo second-order kinetic model and the adsorption thermodynamics followed Langmuir isothermal model very well, and the maximum adsorption capacities (Qmax) of DMP, DEP, and DBP were obtained as 0.95, 1.38, and 7.09 mg g-1, respectively. The Scatchard analysis revealed that the template-polymer system had a two-site binding behavior. The adsorption thermodynamic studies indicated that the adsorption processes were exothermic and spontaneous, and dominated by physical adsorption relying on hydrogen bond, hydrophobic interaction, and van der Waals force. Mag-MMIP@MWCNTs also showed good reproducibility and reusability for simultaneous adsorption of the three PAEs. The potential application of mag-MMIP@MWCNTs was proved by the removal of DMP, DEP, and DBP spiked in environmental water samples.

Determination of Phthalate Esters in Water and Liquid Pharmaceutical Samples by Dispersive Liquid-Liquid Microextraction (DLLME) and Gas Chromatography with Flame Ionization Detection (GC-FID)

A method of dispersive liquid-liquid microextraction (DLLME) with gas chromatographic separation has been developed and applied for the determination of phthalate esters in water samples and liquid pharmaceuticals. The method allows the determination of various phthalate esters with different polarities, namely: dimethyl phthalate, diethyl phthalate, di-iso-butyl phthalate, di-n-butyl phthalate, di(2-ethylhexyl) phthalate and di-n-octyl phthalate, with high values for the enrichment factors (370–390) and extraction recoveries (91–97%). Almost complete isolation of the phthalate esters from water samples was achieved by DLLME using chloroform as the extracting phase containing a minimum of 5–10% acetonitrile, isopropanol, or acetone as the disperser solvent and 10% sodium chloride as the salting-out agent. The results showed that increasing the amount of disperser solvent in the extracting phase leads to the growth in the phase polarity and thus improves the extractability of the polar analytes. The limits of detection determined for a signal-to-noise ratio equal to 3 were in the range from 1.0 to 1.6 µg L−1 and the relative standard deviations for 10.0 µg L−1 were below 9.7% (n = 3). The developed method demonstrates good repeatability and linearity and will be useful for the screening and quantitative determination of phthalate esters in various water samples and liquid pharmaceuticals.

Polymer phase transition characteristics coupled with GC-MS for the determination of phthalate esters.

Phthalate esters are easily released from plastics materials and migrate into the soil and water environment, causing serious pollution and posing a great threat to the health of human beings. A novel temperature-sensitive extractant combined with liquid-liquid microextraction was developed to preconcentrate three phthalates in the water environment. To optimize the extraction efficiency for the three phthalate esters, various parameters, including polymer molecular weight, salt type, salt addition, adsorption time, desorption solvent, desorption volume, and desorption time have been studied. Under optimal conditions, limits of detection and limits of quantification were in the range of 0.007-0.120and 0.021-0.350µg/L, respectively. Linearities varied in the range of 5-1000 µg/L, with the correlation coefficients of 0.9867-0.9997. The preconcentration factors were in the range of 25-75. The relative recoveries of the three phthalate esters were in the range of 82.2-105.6% at the spiked levels. The relative standard deviations were in the range of 0.7-9.2% based on triplicate measurements. The results indicate that the temperature-sensitive material is a good extractant for phthalate esters in water samples.

Enrichment and sensitive determination of phthalate esters in environmental water samples: A novel approach of MSPE-HPLC based on PAMAM dendrimers-functionalized magnetic-nanoparticles

Phthalate esters (PAEs) are an important kind of environmental endocrine disrupting chemicals, and have attracted great attention in environmental field. Present study described a new method for rapid and sensitive determination of PAEs including dibenzyl phthalate (DPhP), dibutyl phthalate (DnPP), and dicyclohexyl phthalate (DCHP) from aqueous matrices based on magnetic solid-phase extraction. Polyamidoamine (PAMAM) dendrimers-grafted magnetic-nanoparticles were synthesized and characterized, and the expected integration of more multifunctional sites of PAMAM dendrimers and rapid separation property was utilized for method development. To achieve the best extraction efficiency, several important parameters were optimized including the dosage of the adsorbent, sample pH, kind and volume of eluent, extraction time, desorption time, ionic strength. Under the optimal conditions, three phthalate esters were well enriched and simultaneously determined by high performance liquid chromatography with variable wavelength detector (VWD). Excellent linearities were observed in the range of 0.1–600 μg L−1 for DPhP and DnPP and 0.5–600 μg L−1 for DCHP, and all correlation coefficients (R2) were larger than 0.997. The limits of detection (LODs, S/N = 3) were ranged from 0.025 to 0.16 μg L−1. The spiked recoveries of PAEs in real water samples were in the range of 93.5–101.8% with satisfied relative standard deviations (RSDs) ranging from 0.9 to 4.1%. The prepared magnetic materials have shown good adsorption capability for PAEs and the developed method earned merits such as high sensitivity, simplicity, rapidness and environmental friendliness, which can be used as a robust alternative tool for monitoring PAEs in water samples.

A modulation approach for covalent organic frameworks: Application to solid phase microextraction of phthalate esters

A modulation approach with 4-hydroxybenzhydrazide as the modulating agent was designed for constructing 2,4,6-triphenoxy-1,3,5-benzene-based covalent organic frameworks (COFs). The COFs materials were employed as solid phase microextraction (SPME) coatings for the extraction of phthalate esters (PAEs). Various experimental conditions including extraction temperature, extraction time, salt concentration, and desorption time were investigated and optimized. The introduction of modulating agent into the synthesis of fibers significantly enhanced the extraction efficiency towards PAEs. The linear range was 1–100 μg L‒1 and the detection limits in the range of 0.032–0.451 μg L‒1 were achieved with good linearity ranged from 0.9904 to 0.9970. Inter-batch and intra-batch relative standard deviations were in the ranges of 0.83–4.67% and 3.08–9.73%, respectively. Moreover, the developed coating fibers were used for the extraction of PAEs in water samples and satisfactory recoveries were achieved.

Contamination Levels and Ecological Risk Assessment of Phthalate Esters (PAEs) in the Aquatic Environment of Key Areas of Taihu Lake

To better understand phthalate esters (PAEs) pollution in key areas of Taihu Lake, water and sediment samples were collected for content analysis. The concentrations of ∑PAEs in water samples from wet, dry, and normal seasons ranged 1.6-11.2 μg·L-1 (mean:3.68 μg·L-1), nd-6.21 μg·L-1 (mean:1.3 μg·L-1), and nd-1.72 μg·L-1 (mean:0.48 μg·L-1), respectively. No differences were found between upstream and downstream samples. DEHP was the predominant component in water samples, whereas DBP exceeded the national surface water environmental quality standards. The total PAE concentration in the sediment ranged between 0.74 and 6.90 μg·g-1 (mean:2.64 μg·g-1), with DBP and DEHP the predominant PAEs. The risk quotient (RQ) results showed that DBP and DEHP contributed the most potentially adverse effects to the aquatic environment in the key areas. The contents of PAEs in sediment were all less than the ERLs, thus posing no significant threat to aquatic organisms. The overall level of PAEs in the study area was moderate compared to those in other areas, including rivers, lakes, and estuaries from cities worldwide. Industrial pollution and urban activities are the major sources of PAEs in the aquatic environment of key areas of Taihu Lake.

Electrospun polycaprolactam-manganese oxide fiber for headspace-solid phase microextraction of phthalate esters in water samples

The nanofibrous polycaprolactam (polyamide 6 (PA6)) incorporated with manganese oxide (MnO) nanoparticles was fabricated by electrospinning and used as a new fiber coating for headspace-solid phase microextraction (HS-SPME) of the selected phthalate esters (PEs) in water samples prior to GC-μECD. The adsorbent was fully characterized using scanning electron microscopy (SEM), Fourier transform-infrared (FT-IR) spectroscopy and thermogravimetric analysis (TGA). The main parameters that affect the HS-SPME efficiency such as extraction temperature, ionic strength, extraction and desorption times were investigated. The analytical figures of merit were obtained under the optimized conditions as follows: linear dynamic range (LDR), 0.500–5.00 × 102 ng mL−1; relative standard deviations (RSDs, n = 3), 1.86–10.9%; limits of detection (LODs), 0.0400–0.193 ng mL−1. The method was applied for determination of the target analytes in river water, bottled water, mineral water and soda samples and the relative recoveries were obtained between 90.3 and 107%.

Microextraction in packed syringe by using a three-dimensional carbon nanotube/carbon nanofiber–graphene nanostructure coupled to dispersive liquid-liquid microextraction for the determination of phthalate esters in water samples

Microextraction in packed syringe (MEPS) was combined with dispersive liquid-liquid microextraction (DLLME) for the extraction of phthalate esters (PEs) from water samples prior to their determination by GC with flame ionization detection. A three-dimensional nanomaterial composed of carbon nanotubes, carbon nanofibers and graphene was prepared by chemical vapor deposition (CVD) and employed as a sorbent for MEPS. The porous structure of the sorbent has been revealed by scanning electron microscopy, transmission electron microscopy, and Brunauer-Emmett-Teller adsorption. The effects of various experimental variables on the extraction efficiencies of the following PEs were studied: Dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, di-n-butyl phthalate, and di-2-ethylhexyl phthalate. After extraction, the GC assay gives a linear calibration plot that covers the 0.02 to 200 ng mL−1 PE concentration ranges. The method displays detection limits (at an S/N ratio of 3) in the range from 1 to 10 ng mL−1. Relative standard deviations for intra-day and inter-day precision are between 5.7 and 8.9%, and between 7.6 and 10.1%, respectively. The feasibility of the method was demonstrated by extracting and determining PEs in (spiked) real water samples, whereby recoveries in the range of 90.3–98.8% and RSD% lower than 10.3% were attained.

Leaching of phthalate esters from different drinking stuffs and their subsequent biodegradation.

Phthalate esters (PAEs) are mainly used as plasticizers, and their release in the environment during the manufacturing, use, and disposal has caused serious environmental health concerns, since some of them are suspected to be mutagens, hepatotoxic agents, and carcinogens. In the present study, leaching of PAEs from different drinking stuffs (water cooler, mineral water bottles) exposed to sunlight and baby feeders subjected to different heating treatments (boiling, autoclave and oven) was studied. Results showed that a total of 10 PAEs were leached and identified. Among them, dimethyl phthalate, bis(2-methoxyethyl) phthalate, diethyl phthalate, and dibutyl phthalate were the major leached PAEs found in the range 9-112.50μgL-1. Boiling treatment was found safer for baby feeders as PAE leaching was ~26-54% less as compared to other two treatments. The leached PAEs in water samples were then subjected to biodegradation experiment with Bacillus thuringiensis strain at optimized conditions (time 72h and 30°C). Hence, leaching of hazardous PAEs from different water stuffs is alarming and needs immediate attention. Moreover, B. thuringiensis strain was found effective for PAE remediation (75-96% degradation) at neutral pH. Graphical abstract ᅟ.

Synthesis of nano-hydroxyapatite sorbent for microextraction in packed syringe of phthalate esters in water samples

An easy alkoxide–based sol–gel method using Ca(NO3)2·4H2O and tri–ethyl phosphate (PO(OC2H5)3; TEP) precursors employed to synthesize nano-hydroxyapatite (HAP). The structural characterization of samples was studied using XRD, TEM and elemental analysis of SEM. Scherrer and Williamson–Hall equations were applied to measurement of the crystallite size distributions and micro–strain of the synthesized HAP powder. The synthesized HAP nanoparticles were applied as an efficient sorbent for the microextraction in packed syringe (MEPS) of phthalate esters (PAEs) from water samples. Separation and determination of the PAEs were performed by gas chromatography–flame ionization detection (GC–FID). Several variables affecting the extraction efficiency of the analytes i.e., desorption solvent, volume of desorption solvent and number of extraction cycles were investigated and optimized. Under optimized conditions, the calibration curves were linear (R > 0.9916) in the concentration range of 0.05–100 ng mL−1. The method displays detection limits (at an S/N ration of 3) in the range from 0.02 to 0.1 ng mL−1, and the limits of quantification (at an S/N ratio of 10) are between 0.07 and 0.25 ng mL−1. Relative standard deviations (RSDs) for intra- and inter-day precision are 4.8–8.3%, and 6.1–8.5%, respectively. The applicability of the developed method was examined by analyzing different water samples (river water, bottled mineral water and tap water) and the relative recovery values for the spiked water samples were found to be in the range of 85.5–99.2%.

Phthalate esters in main source water and drinking water of Zhejiang Province (China): Distribution and health risks

To evaluate the distributions and health risks of phthalate esters in the main source water and corresponding drinking water of Zhejiang Province, the concentrations of 16 phthalate esters in water samples from 19 sites were measured from samples taken in the dry season and wet season. The concentration of the total phthalate ester congeners in source water ranged from 1.07 μg/L to 7.12 μg/L in the wet season, from 0.01 μg/L to 1.58 μg/L in the dry season, from 1.18 μg/L to 15.28 μg/L from drinking water in the wet season, and from 0.16 μg/L to 1.86 μg/L from drinking water in the dry season. Of the 16 phthalate esters, dimethyl phthalate, dibutyl phthalate, di-(2-ethyl-hexyl) phthalate, di-iso-butyl phthalate, bis-2-n-butoxyethyl phthalate, and dicyclohexyl phthalate were present in the samples analyzed, dominated by di-iso-butyl phthalate and di-(2-ethyl-hexyl) phthalate. The concentrations of phthalate esters in the wet season were all relatively higher than those in the dry season, and the drinking water had higher concentrations of phthalate esters than source water. The phthalate ester congeners studied pose little health risk to nearby citizens. Environ Toxicol Chem 2015;34:2205-2212. © 2015 SETAC.

Determination of phthalate esters from environmental water samples by micro-solid-phase extraction using TiO2 nanotube arrays before high-performance liquid chromatography.

We describe a highly sensitive micro-solid-phase extraction method for the pre-concentration of six phthalate esters utilizing a TiO2 nanotube array coupled to high-performance liquid chromatography with a variable-wavelength ultraviolet visible detector. The selected phthalate esters included dimethyl phthalate, diethyl phthalate, dibutyl phthalate, butyl benzyl phthalate, bis(2-ethylhexyl)phthalate and dioctyl phthalate. The factors that would affect the enrichment, such as desorption solvent, sample pH, salting-out effect, extraction time and desorption time, were optimized. Under the optimum conditions, the linear range of the proposed method was 0.3-200 μg/L. The limits of detection were 0.04-0.2 μg/L (S/N = 3). The proposed method was successfully applied to the determination of six phthalate esters in water samples and satisfied spiked recoveries were achieved. These results indicated that the proposed method was appropriate for the determination of trace phthalate esters in environmental water samples.

Application of In-Syringe Dispersive Liquid-Liquid Microextraction Coupled to GC/FID for Determination of Trace Contamination of Phthalate Esters in Water Samples.

In this work, a simple and easy to handle one-step in-syringe setup for the dispersive liquid-liquid microextraction method has been developed for preconcentration of trace quantities of four kinds of phthalate esters (PEs) in water samples as a prior step to its determination by gas chromatography/flame ionization detector. The environmental pollution at this method has been limited due to using a glass syringe as extraction unit and also a very small amount of n-hexane as a safe solvent. Some important parameters such as the type of extraction and disperser solvents, extraction and disperser solvents volume, sample volume and ionic strength were investigated and optimized. Validation experiments showed that the optimized method had precision (1.7-6.9%) and high recovery (94.32-104.7%), and the limits of detection were from 0.406 to 1.33 µg L(-1). At the end, the method was successfully applied for the determination of PEs in real water samples.

Application of magnetic graphitic carbon nitride nanocomposites for the solid-phase extraction of phthalate esters in water samples.

Magnetic graphitic carbon nitride nanocomposites were successfully prepared in situ and used to develop a highly sensitive magnetic solid-phase extraction method for the preconcentration of phthalate esters such as di-n-butyl phthalate, butyl phthalate, dihexyl phthalate, and di-(2-ethyl hexyl) phthalate from water. The adsorption and desorption of the phthalate esters on magnetic graphitic carbon nitride nanocomposites were investigated and the parameters affecting the partition of the phthalate esters, such as adsorption, desorption, recovery, were assessed. Under the optimized conditions, the proposed method showed excellent sensitivity with limits of detection (S/N = 3) in the range of 0.05-0.1 μg/L and precision in the range of 1.1-2.6% (n = 5). This method was successfully applied to the analysis of real water samples, and good spiked recoveries over the range of 79.4-99.4% were obtained. This research provides a possibility to apply this nanocomposite for adsorption, preconcentration, or even removal of various carbon-based ring or hydrophobic pollutants.

Simultaneous determination of four phthalate esters in water samples using ultrasound-assisted dispersive liquid-liquid microextraction coupled with high performance liquid chromatography

Ultrasound-assisted dispersive liquid-liquid microextraction coupled with high performance liquid chromatography (UA-DLLME-HPLC) was developed for the determination of four typical phthalate esters (PAEs). The analyzed PAEs included dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP) and di-n-octyl phthalate (DnOP). The UA-DLLME parameters such as types/volumes of extraction/dispersion solvents, ultrasonic time, ionic strength and extraction time, were investigated. Enrichment factor (EF)was employed to evaluate the extraction efficiency. The conditions were finally chosen: CCl4 (40 microL)/ acetonitrile (1.0 mL) as extraction/dispersion solvents; 30 g/L NaCl; ultrasound/centrifugation of 5 min. Under the optimized extraction conditions, UA-DLLME exhibited strong enrichment ability for the four PAEs. The EFs for DMP, DEP, DBP and DnOP obtained were 71, 144, 169 and 159, respectively. The limits of detection were 3.78, 1.77, 3.07 and 3.30 microg/L for DMP, DEP, DBP and DnOP, respectively. The satisfactory recoveries for three water samples at three spiked levels ranged from 82.99%-114.47%, with the relative standard deviations of 1.93%-8.31%. It is a convenient, speedy, environmentally benign method for the routine analysis of PAEs in water samples.

Phthalate ester leachates in aquatic mesocosms: Implications for ecotoxicity studies of endocrine disrupting compounds

Aquatic mesocosm experiments have become common throughout the fields of ecology and ecotoxicology. Mesocosm containers are often composed of plastic materials as these are lighter and cheaper than steel cattle tanks. Plastics may contain phthalate esters which may leach from containers, potentially confounding experiments via toxicity or endocrine disruption. The objective of this experiment was to determine the extent to which plastic containers (=“tanks”) used for mesocosms leach phthalates, and if there are significant differences between tank types and phthalate profiles. We investigated four tank types: fiberglass, polyethylene, poly-vinyl chloride, and polyethylene tanks containing an established aquatic community. We measured six common phthalate esters in water samples collected from each tank every 2weeks for 8weeks. There was a significant effect of tank type, time, and time x type interactions on phthalate ester concentrations. Di-(2-ethylhexyl) phthalate was the predominant congener measured in all samples. Fiberglass tanks had greater concentrations of dimethyl phthalate compared to other tank types (more than 600x larger concentration), but no other differences in phthalate profiles among tank types were evident. In addition, tanks with established communities had much higher concentrations of most phthalates at the 6 and 8week timepoints. Our study confirms that mesocosm tanks of different materials leach phthalates starting immediately after they are filled and continuing for at least 8weeks, but do so at different rates. Future ecotoxicity experiments should consider the potentially confounding effects of phthalates that may leach from tanks used in experimental mesocosms.

Micro-scale quantitation of ten phthalate esters in water samples and cosmetics using capillary liquid chromatography coupled to UV detection: effective strategies to reduce the production of organic waste

We have extracted ten phthalate esters (C1 to C8) using six different micro-scale methods for extraction, and then separated them by capillary liquid chromatography coupled to UV detection. The methods included liquid-liquid extraction, ultrasonic-assisted extraction, microwave-assisted extraction, dispersive liquid-liquidmicroextraction, dispersive liquid-liquid microextraction solidification of floating organic droplets, and cloud point extraction. The linear range of the analytes is from 0.5 to 50 μg mL−1, and the detection limits range from 0.02 to ~0.17 μg mL−1. The precision and accuracy of all intra- and inter-day analyses are <5.5%. We find that dispersive liquid-liquid microextraction solidification of floating organic droplet (DLLME-SFO) is the best method for quantification of most phthalate esters in water samples and cosmetics because of its low limit of detection and high extraction efficiencies.

Development of an ionic liquid‐based dispersive liquid–liquid micro‐extraction method for the determination of phthalate esters in water samples

Ionic liquid-based dispersive liquid-liquid micro-extraction (IL-DLLME) was coupled with high-performance liquid chromatography-ultraviolet (HPLC-UV) for the determination of four phthalate esters, including butyl benzyl phthalate, di-n-butyl phthalate, dicyclohexyl phthalate and bis(2-ethylhexyl) phthalate in water samples. The mixture of ionic liquid (IL) and dispersive solvent was rapidly injected into 10 mL aqueous sample. Then, IL phase was separated by centrifugation and was determined by high-performance liquid chromatography-ultraviolet. The factors influencing the extraction efficiency, such as type and volume of IL, disperse solvent, extraction time, centrifuging time and ionic strength, were investigated and optimized. Under the optimized conditions, the extraction recoveries by the proposed ionic liquid-based dispersive liquid-liquid micro-extraction for the four phthalates ranged from 83.0 to 91.7%. The relative standard deviations were between 7.8 and 15%. The limits of quantification for four phthalates were between 10.6 and 28.5 μg/L. The proposed method was successfully applied for the analysis of PAEs in tap, lake and treated wastewater samples.