Determination Of Phthalic Acid Esters Research Articles

Fast and reliable determination of phthalic acid esters in soil and lettuce samples based on QuEChERS GC–MS/MS

Phthalates are commonly used as plasticizers, and solvents in industry and households. We propose an application of the QuEChERS method for the determination of six PAEs in the soil and lettuce (roots and leaves) by GC–MS/MS. The QuEChERS method validation procedure was performed and good linearity (>0.997), recovery (97.2–99.1 %), very low detection limits (0.09–0.43 ng/g), and satisfactory inter- and intraday precision (∼4%) were obtained confirming that QuEChERS GC–MS/MS applied for PAEs determination in the environmental samples is a cheap and environmentally friendly method. In general, the higher the number of carbon atoms in PAEs, the higher the percentage noted in the lettuce roots. At higher PAEs concentration (60 ng/g) the main bis(2-ethylhexyl) phthalate (DEHP) sink were roots whereas at lower concentrations (30 ng/g) most of DEHP was noted in lettuce leaves implying that the fate of PAEs was governed not by the chemical structure of PAEs but rather partitioning (logKow).

Determination of phthalic acid esters (PAEs) along with probabilistic health risk assessment in fruit juice samples in Tehran, Iran.

In the present study, magnetic solid phase extraction (MSPE) method and gas chromatography-mass spectrometry (GC/MS) technique were used to measure 6 PAE in fruit juice samples. The mean of total phthalic acid esters (ƩPAEs) in all samples was 3.55 ± 0.66µg/L. The mean concentration of DEHP (bis(2-ethylhexyl) phthalate) in samples was 0.82 ± 0.31µg/L, which was lower than the mentioned United States Environmental Protection Agency (USEPA) standard level in drinking water (6μg/L for DEHP). The pineapple juice samples (4.44 ± 0.57µg/L) and mango juice samples (2.77 ± 0. 1µg/L) had maximum and minimum mean levels of ƩPAEs, respectively. Also, results showed that brand B (3.76 ± 0.87µg/L) and samples in the time of expiration date (3.64 ± 0.72µg/L) had the highest PAE levels. The rank order Chronic Daily Intake (95%) values for adults were DEHP ([Formula: see text]) > butylbenzyl phthalates (BBP) ([Formula: see text]) > diethyl phthalate (DEP) ([Formula: see text]) and for children were DEHP ([Formula: see text]) > BBP (9.07E-04) > DEP ([Formula: see text]), which were below the tolerable daily intake (TDI) value. The noncancer risk of PAEs based on the target hazard quotient (THQ) was acceptable (< 1). The results exhibited that the Incremental Lifetime Cancer Risk (ILCR) was below the permissible limit (< [Formula: see text]). Therefore, the risk of carcinogenicity and noncarcinogenicity of PAEs in juices does not have adverse effects on human health.

Optimization of micro-QuEChERS extraction coupled with gas chromatography-mass spectrometry for the fast determination of phthalic acid esters in mussel samples.

In this study, a new miniaturized version of the analytical method based on the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) technique using Florisil in the cleanup step for extracting six phthalic acid esters (PAEs) in mussel samples was developed by using a design of experiments. For this purpose, 1.5 mL of ultrapure water and later, 1.5 mL of acetonitrile were added to 0.1 g of the lyophilized sample, followed by 0.3 g of a commercial extraction salt packet (magnesium sulfate, sodium chloride, sodium citrate dihydrate, and sodium hydrogencitrate sesquihydrate). The recovered extract was purified using 0.1 g of Florisil. The final extract was evaporated and reconstituted in 1 mL of hexane. The six phthalates were determined by a GC-MS (SIM) system. The whole method was validated at two concentration levels. Recoveries ranged from 79% to 108%. Reproducibility in terms of coefficients of variation was between 4.9% and 12.1%. The limits of quantification of the whole method were between 0.53 and 38.0 μg per kg dry weight. Five mussel samples coming from the Galician Rías were analysed using this method. Except for three of the five samples where DnOP (di-n-octyl phthalate) was below the limit of quantification, all PAEs were found in concentrations that ranged between 1.99 and 372.7 μg per kg dry weight.

Determination of phthalic acid esters and di(2-ethylhexyl) adipate in coffee obtained from capsules

In this work, the ammonium formate version of the QuEChERS method has been applied for the first time to the extraction of a group of nine phthalic acid esters and one adipate from three types of coffee (maximum intensity, intermediate intensity and decaffeinated) prepared from coffee capsules, using gas chromatography coupled to mass spectrometry for analytes separation and determination. Matrix-matched calibration showed good linearity with determination coefficients (R2) higher than 0.9983 for all analytes and matrices. In general, matrix effect assessment revealed a medium effect of signal suppression, while mean relative recovery values were in the range 70–120% with relative standard deviation values ≤19% for most analytes. Several samples of each type of coffee obtained from capsules made of different materials were also analysed, finding concentrations of DBP, DEHA and DEHP in the range 29.3–734 ng/capsule, below the tolerable daily intake established for some of them.

Determination of phthalate acid esters (PAEs) in bottled water distributed in tehran: a health risk assessment study

ABSTRACT In this study, the levels of six PAEs [bis (2-ethylhexyl) phthalate (DEHP), butyl benzyl phthalate (BBP), dibutyl phthalate (DBP), diethyl phthalate (DEP), dimethyl phthalate (DMP) and di-n-octyl phthalate (DNOP)] were determined from four types of bottled water)non-carbonated, mineral, carbonated and carbonated flavoured) using MSPE method (magnetic solid phase extraction) and GC/MS technique (gas chromatography/mass spectrometry). The mean concentration of total PAEs was 6.11 ± 1.43 µg/L. The mean concentration of DEHP was 2.22 ± 0.76 µg/L and was lower than the United States Environmental Protection Agency (USEPA) standard level in drinking water (6 μg/L for DEHP). The highest mean level of total PAE was observed in carbonated water (7.43 ± 2.03 μg/L) and the lowest mean level of total PAE was observed in non-carbonated water (5.15 ± 0.41 μg/L). The Monte Carlo method was applied to calculate the Target Hazard Quotient (THQ), Chronic Daily Intake (CDI), and Incremental Life Cancer Risk (ILCR) indexes. In all samples, the rank order of the estimated THQ values based on the 95% percentile was DEHP (4.77E-4) > DBP (2.25E-5) > BBP (1.99E-5) > DEP (2.75E-6) and there would be unlikely non-carcinogenic risks for consumers (THQ<1). The incremental lifetime cancer risk assessment revealed that phthalate esters (DEHP) in evaluated bottled water samples did not pose a serious concern to humans.

Determination of phthalic acid esters and di(2-ethylhexyl) adipate in fish and squid using the ammonium formate version of the QuEChERS method combined with gas chromatography mass spectrometry

In the present study, the ammonium formate version of the QuEChERS method, considered highly advantageous in relation to instrument maintenance and other issues, was applied for the first time to extract a group of twelve phthalic acid esters (PAEs, i.e. dipropyl phthalate, DPP; diisobutyl phthalate, DIBP; dibutyl phthalate, DBP; diisopentyl phthalate, DIPP; di-n-pentyl phthalate, DNPP; dihexyl phthalate, DHP; butyl benzyl phthalate, BBP; dicyclohexyl phthalate, DCHP; di(2-ethylhexyl) phthalate, DEHP; di-n-octyl phthalate, DNOP; diisononyl phthalate, DINP; and diisodecyl phthalate, DIDP) and one adipate (di(2-ethylhexyl) adipate, DEHA) from two species of fish (Scomber colias and Katsuwonus pelamis) and one of squid (Loligo gahi). The method was validated in terms of linearity, trueness and matrix effects. Determination coefficients (R2) for matrix-matched calibration curves were higher than 0.99 in all cases, being the lowest calibration levels in the range 0.5–10 ng/g. Mean recovery values were between 70 and 117% with relative standard deviation values ≤20%. Matrix effects were soft (between −20 and +20%) for most analytes and matrices, except in squid samples, which was mostly medium with a moderate ion suppression. The analysis of 10 samples of each type showed the presence of DIBP, DBP and DEHP at concentrations up to 44.2 ± 2.1 ng/g of wet weight in some of the samples and species, still not representing concerning values when considering the daily intake of such species of seafood in the human diet (tolerable daily intake -TDI- values were not exceeded). Results demonstrated that the ammonium formate version of the QuEChERS method can be applied with success for the extraction and determination of the selected PAEs and DEHA in fish and squid samples.

Fast and Reliable Determination of Phthalic Acid Esters in the Blood of Marine Turtles by Means of Solid Phase Extraction Coupled with Gas Chromatography-Ion Trap/Mass Spectrometry.

The presence of phthalic acid esters (PAEs) in marine environments is an important issue. These chemicals are able to affect marine organisms, particularly marine turtles, and to act as endocrine disrupters. In this paper, for the first time, a simple and reproducible analytical method based on solid-phase extraction (SPE) coupled with gas chromatography—ion trap/mass spectrometry (GC-IT/MS) was developed for the extraction of phthalates from the blood of marine turtles. The extraction was obtained by using C18 phthalates-free as the stationary phase. In order to individuate the best working conditions for the extraction, the adsorption isotherms and breakthrough curves were studied. The overall analytical methodology was validated in terms of limit of detection (LOD, 0.08–0.6 ng mL−1), limit of quantification (LOQ, 0.4–0.8 ng mL−1), and correlation coefficients (>0.9933). By using this procedure, percentage recoveries ranging from 89 to 103% were achieved. The precision parameters (intra-day and inter-day) were studied, and the obtained values were smaller than 12.5%. These data confirm the goodness of the proposed analytical methodology, which is applied to real samples.

Surface blocking of azolla modified copper electrode for trace determination of phthalic acid esters as the molecular barricades by differential pulse voltammetry: response surface modelling optimized biosensor.

In this work, a sensitive and efficient voltammetric biosensor was introduced for differential pulse voltammetric (DPV) determination of some phthalic acid esters (PAEs) including dibutyl phthalate (DBP), dimethyl phthalate (DMP), di(2-ethylhexyl)phthalate (DEHP) and dicyclohexyl phthalate (DCHP) in aqueous solutions. Briefly, the surface of a copper electrode was modified by azolla paste prepared using azolla powder and electroencephalography gel (EEG). The modified surface was characterized by electrochemical impedance spectroscopy (EIS), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), Brunauer–Emmett–Teller (BET) analysis and energy dispersive X-ray (EDX) methods. Determination of PAEs was conducted based on their blocking effect on the electrode surface for ferrous ion oxidation. The central composite design (CCD) was conducted to optimize the effects of four experimental parameters including the concentration of Fe2+ ions (CFe2+) and supporting electrolyte (Csup. elec), solution pH and modifier/gel mass ratio on the decrease in the anodic peak current of ferrous ions as the response. Predicted optimal conditions (CFe2+= 319 μM, Csup. elec= 0.125 M, pH = 7.52 and modifier/gel mass ratio = 0.19) were validated by experimental checking which resulted in an error of 1.453%. At the optimum conditions, linear relationships were found between the DPV responses and PAEs concentrations and the limit of detection (LOD) and limit of quantification (LOQ) values were in the ranges of 0.2–0.4 μg L−1 and 0.5–1.0 μg L−1, respectively. Good recovery percentages ranging from 97.3 to 100.3% with RSD < 3.2% suggested the proposed method for efficient, accurate and quick determination of PAEs in real water samples.

Chromatographic Methods for the Determination of Phthalic Acid Esters in Different Samples

Phthalic acid esters or phthalates are synthetic chemical compounds which were introduced in the early 1920s. The widespread applications of phthalates lead to their ubiquity in the surroundings and also have posed a serious threat to living organisms including human beings. Therefore, determination of phthalates in different environmental matrices is imperative to know their potential impacts on various ecosystems and human health. The determination of phthalates in complex natural matrices requires extensive sampling, correct sample preparation, identification, confirmation and quantification using well-established analytical methods. The present work is an outcome of the extensive literature survey on extraction methods and chromatographic determination of phthalates in environmental, biological and other samples. The commonly used extraction methods are liquid–liquid extraction, solid phase extraction, solid–liquid extraction, solid phase micro-extraction, Soxhlet mediated extraction, supercritical CO2 extraction, etc. Apart from extraction methods, we have discussed chromatographic systems particularly gas chromatography, liquid chromatography, high-performance liquid chromatography or ultra high-performance liquid chromatography, etc. In analytical instruments, the commonly preferred detectors are mass spectrometry, tandem mass spectrometry, flame ionization detector, and time-of-flight mass spectrometry.

Magnetic Graphene Dispersive Solid-Phase Extraction for the Determination of Phthalic Acid Esters in Flavoring Essences by Gas Chromatography Tandem Mass Spectrometry.

In the present study, a sensitive, efficient and repeatable method for the simultaneous extraction and determination of 13 types of phthalic acid esters (PAEs) in flavoring essence samples using magnetic graphene solid-phase extraction coupled with gas chromatography tandem mass spectrometry was developed. Due to the unique structure of magnetic graphene, it has several advantages, such as large surface area and fast separation ability. This unique structure not only provided strong magnetic responsiveness for the separation but also prevented the self-aggregation of graphene. The large delocalized p-electron system of graphene can form strong π-stacking interactions with the benzene ring. Thus, graphene may be also a good candidate adsorbent for the adsorption of benzenoid-form compounds. Several magnetic soild-phase extraction parameters, such as elution solvents, amounts of sorbents, enrichment time and desorption time were optimized. The optimized procedures for this method were performed by ultrasonication using ethyl acetate as elution solvent for 5min. Under the optimal conditions, the developed method provided spiked recoveries of 75.0-105.3% with relative standard deviations of ~5.6% and limits of detection were 0.011-0.091mg/kg. Good linear relationships were observed with the coefficient of determination (R2)>0.993 for all the analytes. Finally, the validated method was successfully applied to the analysis of PAEs in real samples.

A novel temperature controlled switchable solvent based microextraction method: Application for the determination of phthalic acid esters in water samples

In this work, a novel temperature controlled switchable solvent based microextraction method has been developed for the extraction and preconcentration of four PAEs from water samples prior to GC–MS analysis. For the first time, the effect of temperature in the switching of extracting solvent has been studied and the application of cooling/heating processes instead of addition of chemicals in the switchable solvent based microextraction has been used for PAEs extraction. Several parameters including solvent type, solvent volume, temperature of dissolution, temperature of separation, and salt addition are optimized. A theoretical study also has been provided to reveal the effect of cooling/heating effects on the homogenization and separation of phases. The proposed method provided some advantages such as simplicity, using low volumes of inexpensive and less hazardous reagents, rapid extraction and reduced analysis time. For the developed method, LODs and LOQs were obtained in the ranges of 0.03–0.06 and 0.1–0.2 µgL−1 respectively. Also, calibration curves were linear within the range of 0.2–100 µgL−1 for dimethyl phthalate and dibutyl phthalate, and 0.1–100 µgL−1 for diethyl phthalate and dioctyl phthalate. Enrichment factors were found to be in the range of 110.9–116.3. The proposed method was applied for the determination of PAEs in real water samples.

Determination of selected dichloroanilines and phthalates in lyophilised mussels samples with ultra-high performance liquid chromatography-tandem mass spectrometry after QuEChERS clean-up

ABSTRACT Mussels, a marine filter organism, constitute a food product and an established sentinel organism for marine pollution. An analytical method following a QuEChERS extraction and clean-up protocol has been developed for the determination of phthalic acid esters (PAE), including di-n-octyl phthalate (DnOP), di-(2-ethyl hexyl) phthalate (DEHP), butyl benzyl phthalate (BBP), di-methyl phthalate (DMP) and di-n-butyl phthalate (DnBP), as well as 3,4-dichloroaniline and 3,5-dichloroaniline in lyophilised mussels samples. A gradient elution program starting from 40% A (methanol-0.1% formic acid) – 60% B (H2O-0.1% formic acid) up to 100% A was applied, with a total duration of 15 min, at a flow rate of 200 μL min−1 using a 1.8 μm particle size C18 analytical column. All target analytes were detected with a triple quadrupole MS, using electrospray ionisation (ESI) in positive ionisation mode, in SRM mode under optimised conditions. Sample preparation consisted of lyophilisation of the mussels sample and grinding, followed by a QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) protocol. Among the different dispersants evaluated for sample clean-up effectiveness, primary secondary amine (PSA) was found to be the most efficient. Results indicated good chromatographic separation, fast sample preparation procedure, low LODs and LOQs, good trueness expressed as recovery and good precision as evaluated by RSD. In the mussels samples examined DEHP was the most abundant PAE, reaching a maximal concentration of 280 μg/kg of lyophilised weight whereas the levels of DnBP were at approximately 36% of the legal migration limit in foods determined by the EU.

Chemometrics-Assisted QuEChERS Method Coupled with HPLC-Diode Array Detection for the Determination of Phthalate Esters in Food-Grade Plastics

An effective method for the determination of four phthalate esters in plastic products for food usage was developed using the quick, easy, cheap, effective, rugged, and safe (QuEChERS) approach coupled with HPLC-diode array detection. Both the extraction and clean-up steps of the procedure were optimized using chemometrics methods. Under the optimized conditions, calibration model was linear from 10.0 to 500 μg/kg for benzyl butyl phthalate and from 5.0 to 500 µg/kg for dimethyl phthalate, dibutyl phthalate and diethylhexyl phthalate (R2 ≥ 0.9859). The limits of detection and of quantification were less than 3 and 7 μg/kg, respectively. The repeatability and intermediate precision of the proposed method (relative standard deviations) were ≤6.4 and ≤9.2%, respectively. The proposed method is easy, precise, and accurate, and applicable for the determination of phthalic acid esters in plastics for food use classified as polyethylene terephthalate and polystyrene.

Preparation and application of a magnetic plasticizer as a molecularly imprinted polymer adsorbing material for the determination of phthalic acid esters in aqueous samples.

A novel magnetic plasticizer molecularly imprinted polymer adsorbing material (MIP@mSiO2 -β-CD@Fe3 O4 ) was successfully synthesized for the determination of six phthalic acid esters in water, milk, and wine samples. The molecularly imprinted polymers were prepared via precipitation polymerization and a surface molecular imprinting technique, using a cyclodextrin-modified magnetic meso-porous material (mSiO2 -β-CD@Fe3 O4 ) as a magnetic supporter, dibutyl phthalate and butyl benzyl phthalate as the dual template molecules, methacrylic acid as the functional monomer, and ethyleneglycol dimethacrylate as the cross-linking agent. The polymers were characterized by scanning electron microscopy, IR spectroscopy, and X-ray powder diffraction. Thermogravimetric analysis and static and dynamic adsorption experiments were carried out to assay its stability and selectivity. Under optimal experimental conditions, a magnetic solid-phase extraction with MIP@mSiO2 -β-CD@Fe3 O4 coupled to gas chromatography and mass spectrometry method was successfully developed for the determination of phthalic acid esters. The established method achieved a good linear range of 0.10∼8.00μg/mL (R>0.99) and a low detection limit within the range of 1.0∼5.0μg/L. An average recovery rate of 80.2∼103% with relative standard deviation<6.7% was obtained upon the application of the developed method to detect phthalic acid esters in actual aqueous samples.

Determination of phthalic acid esters in water samples by hollow fiber liquid-phase microextraction prior to gas chromatography tandem mass spectrometry

A new hollow fiber liquid-phase microextraction (HF-LPME) method has been developed for the extraction of a group of phthalic acid esters (PAEs) of interest from different water samples prior to gas chromatography tandem mass spectrometry analysis. HF-LPME was carried out using 1-octanol as extraction solvent followed by a back extraction step with cyclohexane. The different parameters that affect HF-LPME such as sample pH, ionic strength, extraction time, stirring rate, extraction temperature and back extraction conditions were investigated. The optimized conditions involved the extraction of 10 mL of sample without pH adjustment or addition of salt during 75 min under a stirring of 850 rpm at 60 °C and subsequent desorption with 200 μL of cyclohexane for 10 min in an ultrasonic bath. The method was validated in terms of calibration and recovery studies using dibutyl phthalate-d4 as internal standard. The developed procedure gave satisfactory recovery (74–120%) and relative standard deviation values (<20%) for the studied PAEs in mineral, tap, pond and waste water samples.

Determination of phthalic acid esters in water samples using core-shell poly(dopamine) magnetic nanoparticles and gas chromatography tandem mass spectrometry

In this work, the first application of core-shell poly(dopamine) magnetic nanoparticles as sorbent for the extraction of a group of eleven phthalic acid esters of interest (i.e. diethyl phthalate (DEP), dipropyl phthalate (DPP), dibutyl phthalate (DBP), bis-isopentyl phthalate (DIPP), bis-n-pentyl phthalate (DNPP), benzylbutyl phthalate (BBP), dicyclohexyl phthalate (DCHP), di-(2-ethylhexyl) phthalate (DEHP), di-n-octyl phthalate (DNOP), diisononyl phthalate (DINP) and diisodecyl phthalate (DIDP)) and one adipate (bis (2-ethylhexyl) adipate, DEHA) from different water samples (Milli-Q, mineral, tap, pond and waste water) is proposed. Analysis were carried out by gas chromatography triple quadrupole tandem mass spectrometry. Parameters that affect the extraction performance were optimized following a step by step approach, being the optimum conditions the extraction of water at pH 6, with 60mg of sorbent and the elution with 6mL of dichloromethane. The methodology was validated for the five selected water samples using DBP-d4 as internal standard. Determination coefficients of matrix-matched calibration curves were above 0.9904 in all cases while relative recovery values ranged between 71 and 120%, with relative standard deviation values below 19%. The limits of quantification of the method ranged between 9 and 20ng/L. Matrix effects were found for most analytes and water samples. Real water samples were also analyzed, finding DEP and DBP at concentrations below 4.20 and 1.23μg/L, respectively, in mineral, tap and waste water. DCHP, DEHP and BBP were also found in some of the samples at concentrations below the LOQs of the method.

Development of a simple and valid method for the trace determination of phthalate esters in human plasma using dispersive liquid-liquid microextraction coupled with gas chromatography-mass spectrometry.

A new method was developed for the trace determination of phthalic acid esters in plasma using dispersive liquid-liquid microextraction and gas chromatography with mass spectrometry analysis. Plasma proteins were efficiently precipitated by trichloroacetic acid and then a mixture of chlorobenzene (as extraction solvent) and acetonitrile (as dispersive solvent) rapidly injected to clear supernatant using a syringe. After centrifuging, chlorobenzene sedimented at the bottom of the test tube. 1μL of this sedimented phase was injected into the gas chromatograph for phthalic acid esters analysis. Different factors affecting the extraction performance, such as the type of extraction and dispersive solvent, their volume, extraction time, and the effects of salt addition were investigated and optimized. Under the optimum conditions, the enrichment factors and extraction recoveries were satisfactory and ranged between 820-1020 and 91-97%, respectively. The linear range was wide (50-1000ng/mL) and limit of detection was very low (1.5-2.5ng/mL for all analytes). The relative standard deviations for analysis of 1μg/mL of the analytes were between 3.2-6.1%. Salt addition showed no significant effect on extraction recovery. Finally, the proposed method was successfully utilized for the extraction and determination of the phthalic acid esters in human plasma samples and satisfactory results were obtained.

Determination of phthalate acid esters (PAEs) in carbonated soft drinks with MSPE/GC–MS method

In this study, at first were prepared novel multi-walled carbon nanotubes modified with catalytic nanoparticles of iron oxide and silver (MWCNTs-Fe3O4/Ag) by mixing the magnetic particles. Due to their excellent absorption and desorption capability towards hydrophobic compounds, the magnetic MWCNTs were used as adsorbent of magnetic solid-phase extraction (MSPE) to extract phthalate acid esters (PAEs). Our results showed the highest concentration of phthalate esters of bis(2-ethylhexyl)phthalate (DEHP) which is much higher than the standard level in the four samples (6766.6, 9201, 9301.6, and 14,008 ng/L). Finally, the established MSPE-GC/MS method was successfully applied to the determination of PAEs from carbonated soft drinks and the MSPE-GC/MS method developed in current study provides a new option for the detection of PAEs from carbonated soft drinks with complex matrices.

Determination of PAEs by Integrative Coupling Method of Headspace in-Tube Microextraction and Reverse-Flow Micellar Electrokinetic Capillary Chromatography

An integrative coupling approach of headspace in-tube microextraction (HS-ITME) and reverse-flow micellar electrokinetic capillary chromatography (RF-MECC) was proposed for determination of phthalic acid esters (PAEs). In the novel method, by placing a capillary filled with background electrolyte (BGE) of RF-MECC in the HS above the sample solution, the PAEs were extracted into the acceptor phase in the capillary. Then, the extracts were separated and determined by RF-MECC. The influence of some essential BGE components such as sodium dodecyl sulfate (SDS) and organic modifier concentrations were investigated. Extraction parameters were also systematically investigated, including the extraction temperature, extraction time, salt concentration, and volume of the sample solution. Under the optimized conditions, enrichment factors for three PAEs were 169, 2534, and 1526, respectively. The proposed method provided a good linearity, low limits of detection, and good repeatability (RSDs below 5.44%, n = 5). This method was then utilized to analyze the three PAEs in tap water, seawater, and beverage samples. The results indicated that the developed method is an excellent alternative for the PAE routine analysis in the food field.

Determination of Phthalic Acid Esters in Seawater and Sediment by Solid-phase Microextraction and Gas Chromatography-Mass Spectrometry

Abstract Phthalic acid esters (PAEs), as the most important plasticizers, are widely used in the production of plastic products. The accurate analysis of PAEs in seawater and sediment would be of great significance in studying the transformation of PAEs and their ecological effects in marine environment. In this study, the method of gas chromatography-mass spectrum detector coupled with solid-phase microextraction was established to analyze the concentration of PAEs in seawater and sediment, and the experimental conditions, such as extraction time and extraction temperature, were optimized. Under the optimum conditions, the precision of this method was less than 10.0%, and the limits of detection were 0.04–0.32 ng L −1 and 0.12–1.6 μg kg −1 . Except dimethyl phthalate, the recovery of PAEs in seawater and sediment ranged from 68.0% to 114.0% and 76.4% to 105.0%, respectively. Moreover, the concentrations of PAEs measured by the method were 0.270–1.39 μg L −1 and 0.79–34.8 μg kg −1 in seawater and sediment samples of Changjiang River Estuary and its adjacent area, respectively. In conclusion, the analytical method is easy to operate and reduces the extraction volume of seawater. Thus, this method meets the requirements of the analysis of PAEs in coastal seawater and sediment.