Evaluation of the Removal of Selected Phthalic Acid Esters (PAEs) in Municipal Wastewater Treatment Plants Supported by Constructed Wetlands.

Phthalic acid esters (PAEs) have a negative impact on living organisms in the environment, therefore, are among the group of Endocrine Disrupting Compounds (ECDs). Unfortunately, conventional methods used in municipal wastewater treatment plants (MWWTPs) are not designed to eliminate PAEs. For this reason, the development of cheap and simple but very effective techniques for the removal of such residues from wastewater is crucial. The main aim of this study was the evaluation of the removal of six selected PAEs: diethyl phthalate (DEP), di-n-octyl phthalate (DOP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), bis(2-ethylhexyl) phthalate (DEHP) and dimethyl phthalate (DMP), in real MWWTPs supported by constructed wetlands (MWWTP-CW system). For the first time, the possibility of using three new plants for this purpose, Cyperus papyrus (papyrus), Lysimachia nemorum (yellow pimpernel) and Euonymus europaeus (European spindle), has been presented. For determining the target PAEs in wastewater samples, a method of SPE (Solid-Phase Extraction)-GC-MS(SIM) was developed and validated, and for plant materials, a method of UAE (Ultrasound-Assisted Extraction)-SPE-GC-MS(SIM) was proposed. The obtained data showed that the application of the MWWTP-CW system allows a significant increase in the removal of DEP, DBP, BBP and DEHP from the wastewater stream. Euonymus europaeus was the most effective among the tested plant species for the uptake of analytes (8938 ng × g-1 dry weight), thus, this plant was found to be optimal for supporting conventional MWWTPs.

Extraction of phthalic acid esters from soft drinks and infusions by dispersive liquid-liquid microextraction based on the solidification of the floating organic drop using a menthol-based natural deep eutectic solvent.

In this work, a natural deep eutectic solvent (NADES) consisting of L-menthol and acetic acid in a 1:1 molar ratio has been applied as extraction solvent for the dispersive liquid-liquid microextraction based on the solidification of the floating organic drop (DLLME-SFO) of a group of nine phthalic acid esters (dipropyl phthalate, DPP; butyl benzyl phthalate, BBP; dibutyl phthalate, DBP; dicyclohexyl phthalate, DCHP; diisopentyl phthalate, DIPP; di-n-pentyl phthalate, DNPP; di(2-ethylhexyl) phthalate, DEHP; diisononyl phthalate, DINP; and diisodecyl phthalate, DIDP) from three common infusions (camomile, pennyroyal mint, and linden teas) and three soft drinks (green tea, tonic, and lime and lemon drink), using dihexyl phthalate (DHP) and di-n-octyl phthalate (DNOP) as internal standards. After the DLLME-SFO procedure, analyses were carried out by high-performance liquid chromatography with UV detection. Method calibration showed good linearity for all the analytes and matrices, with determination coefficients (R2) higher than 0.9910. Relative recovery values were between 71 and 125 %, with relative standard deviation values in the range 1-22 % for the six types of samples, while the limits of quantification of the method were in the range 4.3-51.1 µg/L for infusions and in the range 3.5-33.3 µg/L for soft drinks. Several samples purchased in different local supermarkets were analysed, finding DPP, DBP, DIPP, DEHP and DINP, although only DPP, DBP and DEHP could be quantified in some of them.

Simple method for determining phthalate diesters and their metabolites in seafood species using QuEChERS extraction and liquid chromatography-high resolution mass spectrometry.

In this article we describe a new and simple analytical method based on the Quick, Easy, Cheap, Effective, Rugged and Safe technique followed by dispersive solid-phase extraction clean-up with C18 and Lipifiltr® and LC-HRMS for simultaneously extracting six phthalate diesters and six of their metabolites (phthalate monoesters) from highly consumed seafood species. The method was validated for seafood with high and low lipid contents. Apparent recoveries were up to 79% for all compounds. Matrix effect values ranged from -8 to -48% for all compounds in both types of matrices. Method limits of detection were 1-25 ng g-1 dry weight (d.w.) for most compounds. Five seafood species were analysed using this method, and several phthalate diesters and monoesters were successfully quantified. Phthalate diesters were found at concentrations of up to 982 ng g-1 (d.w.) and phthalate monoesters were found at concentrations of up to 178 ng g-1 (d.w.).

Targeted and untargeted gas chromatography-mass spectrometry analysis of honey samples for determination of migrants from plastic packages.

Plastic food packages usually contain additives which may migrate from the package into the food and then be ingested by the consumer, representing a risk for their health. In this study, targeted and untargeted analysis by gas chromatography-mass spectrometry (GC-MS) is proposed to monitor any contaminants of this type in honey. The application of dispersive liquid-liquid microextraction (DLLME) as a preconcentration technique allowed very low detection limits to be reached for all the substances. Fifteen target compounds, including styrene, phthalates, fatty acids, alkylphenols and bisphenol A, were quantified. Untargeted analyses were also carried out, allowing other migrants in the honey samples to be identified, such as two phthalates, four acids, three esters, one aldehyde, one hydrocarbon and two alkyl phenol compounds. The proposed method was seen to be a useful approach for the quantification and identification of potential migrants from plastics in challenging samples such as honey.

Enhanced microextraction of endocrine disrupting chemicals adsorbed on airborne fine particulate matter with gas chromatography-tandem mass spectrometric analysis.

A novel double-microextraction approach, combining dispersive liquid-liquid microextraction (DLLME) and vortex-assisted micro-solid-phase extraction (VA-µ-SPE) was developed. The procedure was applied to extract endocrine disrupting chemicals (EDCs) consisting of three phthalate esters (PEs) and bisphenol A (BPA) associated with PM2.5 (airborne particulate matter with aerodynamic diameter ≤ 2.5 µm). Gas chromatography-tandem mass spectrometry (GC-MS/MS) was used for determination of the analytes. These analytes were first ultrasonically desorbed from PM2.5 in a 10% acetone aqueous solution. DLLME was used to first preconcentrate the analytes; the sample solution, still in the same vial, was then subjected to VA-µ-SPE. The synergistic effects provided by the combination of the microextraction techniques provided advantages such as high enrichment factors and good cleanup performance. Various extraction parameters such as type and volume of extractant solvent (for DLLME), and type of sorbent, extraction time, desorption solvent, volume of desorption solvent and desorption time (for µ-SPE) were evaluated. Multi-walled carbon nanotubes were found to be the most suitable sorbent. This procedure achieved good precision with intra- and inter-day relative standard deviations of between 1.93 and 9.95%. Good linearity ranges (0.3-100 ng/mL and 0.5-100 ng/mL, depending on analytes), and limits of detection (LODs) of between 0.07 and 0.15 ng/mL were obtained. The method was used to determine the levels of PEs and BPA in ambient air, with concentrations ranging between below the limits of quantification and 0.48 ng/m3. DLLME-VA-µ-SPE-GC-MS/MS was demonstrated to be suitable for the determination of these EDCs present in PM2.5.

Monitoring Phthalates in Table and Fortified Wines by Headspace Solid-Phase Microextraction Combined with Gas Chromatography-Mass Spectrometry Analysis.

Phthalates are a class of endocrine disruptors extensively used in plastic production as plasticizers, and as a result, they can be found in foods as a result of their migration ability. The occurrence of phthalates was monitored in 20 Portuguese wines using a simple, reliable, and environmentally friendly analytical method, headspace solid-phase microextraction combined with gas chromatography-mass spectrometry. Satisfactory figures of merit of method, linearity (correlation coefficient of ≥0.992), recovery (80.3-107.6%), precision (relative standard deviation of <13%), and limits of detection (0.03-0.11 µg/L) and quantification (0.09-0.36 µg/L) were achieved. Dibutyl phthalate and di-n-octyl phthalate were found in measurable quantities in table and fortified wines. The obtained results revealed that these wines do not represent any concern for human exposure, because their concentrations were lower than the tolerable daily intakes established by the European Food Safety Authority.

Graphene oxide/ layered double hydroxides@ sulfonated polyaniline: A sorbent for ultrasonic assisted dispersive solid phase extraction of phthalates in distilled herbal beverages.

In this study, the ultrasonic-assisted dispersive solid phase extraction (UA-d-SPE) method coupled to gas chromatography-mass spectrometry (GC-MS) was applied for the analysis of phthalate esters in drinking water and distilled herbal beverages (Rosa, Mentha, Cichorium). A new nanocomposite based on layered double hydroxide supported on graphene oxide was synthesized and modified by sulfonated polyaniline via a simple one-pot in-situ polymerization method. The structure and morphology of the nanocomposite was confirmed by means of complementary techniques: Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and transmission electron microscopy. The effects of key parameters including adsorbent mass, type and amount of back extraction solvent, extraction and desorption time, pH of the solution and ionic strength were optimized and good precision and sensitivity were achieved. Under the optimum conditions, the limits of detection were between 0.06-0.3 ng mL-1 in aqueous solutions. The hybrid nanomaterial exhibited good adsorption ability toward phthalates in drinking water and distilled herbal beverages. The relative standard deviations (RSD%) for beverage samples varied from 0.1% to 9.9% (n = 3). The relative recoveries varied from 54.5% to 112.6%.

Recent advances in Baijiu analysis by chromatography based technology-A review.

Baijiu, a conventional fermented beverage with thousands history, plays a crucial part in physical health of people and social culture in China. The application of high-throughput screening and confirmation of flavor components in the field of authenticity identification and potential function has attracted more and more attention and interest of researchers. With more attention to health, pesticides residues, phthalates, biogenic amines and other hazardous substances remained in Baijiu have also become the quality parameters concerned by consumers. This review aims to present updated and critical overview on the substances analysis of Baijiu by means of hyphenated chromatographic techniques based on various pretreatment approaches in recent years. Subsequently, the advance and main direction of Baijiu composition analysis were evaluated and prospected.

Magnetic solid-phase extraction based on magnetic carbon particles from coffee grounds for determining phthalic acid esters in plastic bottled water.

Newly developed magnetic carbon particles prepared from coffee grounds were used as the sorbent for the magnetic solid-phase extraction of eight phthalic acid esters (PAEs) from plastic bottled water prior to their analysis by GC-MS. The method, which uses coffee-ground particles coated with iron oxide, was validated, and exhibited linearities for the eight PAEs, with coefficients of determination above 0.998 in the 0.005 to 0.1 mg/L concentration range. Limits of detection and limits of quantification of 0.00003 to 0.002 mg/L and 0.0001 to 0.005 mg/L, respectively, were achieved, with recoveries (%) ranging between 77% and 120%, and relative standard deviations for intra- and interday precisions below 16.3% at three fortification levels. No PAE residues were detected when the developed and validated method was applied to 10 real plastic bottled water samples. Taken together, the developed magnetic solid-phase extraction method is a useful tool for monitoring phthalate esters in aqueous samples. PRACTICAL APPLICATION: The development of a new, inexpensive, and efficient magnetic sorption material derived from spent coffee grounds, and its ability to determine phthalate esters in aqueous solutions was described by GC-MS/MS. The developed magnetic solid-phase extraction method is a useful tool for monitoring phthalate esters in aqueous samples.

In situ growth of covalent organic framework on titanium fiber for headspace solid-phase microextraction of 11 phthalate esters in vegetables.

Vegetables are easily contaminated by phthalate esters (PAEs) from the environment, agricultural films and fertilizers, affecting human health. In this paper, titanium dioxide (TiO2) nanotube arrays were prepared by electrochemical anodic oxidation on the surface of titanium wire. Covalent organic framework of TpBD was in situ bonded to the titanium wire via TiO2 nanotube arrays using monomers of 1,3,5-trimethylphloroglucinol (Tp) and benzidine (BD). The fabricated TpBD-TiO2 coated titanium wire was used as the solid-phase microextraction fiber to extract 11 PAEs in vegetable samples. Coupled with gas chromatography-tandem mass spectrometry (GC-MS/MS), the limits of detection for PAEs were from 0.001 (di-n-butyl phthalate) to 0.430 (butyl benzyl phthalate) µg/L (S/N = 3) and enrichment factors were between 226 (dimethyl phthalate) and 2154 (di-n-butyl phthalate). Our fabricated TpBD-TiO2 fiber can be used at least 150 times without significant loss of extraction efficiency (<4.8%). Quantitative determination of PAEs in vegetable samples (tomato, lettuce, cucumber) was achieved by standard addition.

Hollow fiber-solid phase microextraction of phthalate esters from bottled water followed by flash evaporation gas chromatography-flame ionization detection.

A solid phase microextraction coupled with flash evaporation gas chromatography method was applied to the determination of phthalate esters (PAEs). Polysulfone (PSF) hollow fiber at 1 cm length was employed as extraction element to adsorb PAEs directly. Predominant parameters including stirring velocity, salt concentration, extraction time and extraction temperature were optimized. PSF fiber with absorbed PAEs was put into a small sample cup. The extracted analytes were thermally desorbed at 300 °C in a pyrolyzer, and then entered into a column for separation. The linearity of the method was satisfactory over a concentration range of 2-1000 µg/L with the correlation coefficients r>0.99 for all analytes except dimethoxyethyl phthalate. The relative standard deviations for peak areas were below 9.5% (n = 6). The developed technique achieved high enrichment factors (280-9930 times) and low limits of detection (0.001-0.130 µg/L). The recoveries over the range of 87.0-117.7% were obtained by analyzing real spiked samples. The results demonstrated that this was a simple, environmentally friendly and accurate method for the determination of PAEs in bottled water samples.

Improved purified terephthalic acid wastewater treatment using combined UAFB-SBR system: At mesophilic and ambient temperature.

In this study, a combined UAFB-SBR process was introduced to improve the treatment efficiency of PTA wastewater. The techno-economic feasibility of the process was evaluated in terms of organic removal efficiencies under mesophilic (37 °C) and ambient temperature (15-25 °C) during the long-term run. The lab-scale study revealed that all organic compounds present in the PTA wastewater could be efficiently removed under both mesophilic and ambient temperature, and p-toluic acid is probably the critical pollutant regulating the overall process performance in anaerobic stage, which should be seriously considered. The Miseq Sequencing results suggested that, along with the system temperature variation from mesophilic to ambient temperature, greater effects on bacterial community than archaeal community were detected in the UAFB reactor, while only slight variations were observed in the SBR reactor. Further taxonomy analysis demonstrated that within the UAFB reactor, the syntrophic partnership of Syntrophorhabdus, Syntrophus and Desulfovibrio with hydrogenotrophic methanogens were the main impetus for aromatic organics reduction. In the meanwhile, the intensively identified Thauera and Azoarcus groups were speculated of important roles in the aerobic degradation of aromatic compounds.

A miniature stainless steel net dumbbell-shaped stir-bar for the extraction of phthalate esters in instant noodle and rice soup samples.

This work reports the development of a very-simple-to-construct stir-bar extraction device so called "a dumbbell-shaped stainless steel stir-bar." The extraction device was assembled from a rolled up stainless steel net filled with an XAD-2 sorbent and a metal rod to allow the use of a magnetic stirrer during extraction. The dumbbell-shaped stainless steel stir-bar was used to extract diethyl phthalate (DEP), dibutyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP) before analysis by a gas chromatograph equipped with an electron capture detector (GD-ECD). Under the optimal conditions, the developed method provided a good linearity from 10.0 to 1,000.0 ng mL-1 for all three compounds. Limits of detection and limits of quantification were 9.37 ± 0.29 ng mL-1 and 31.22 ± 0.95 ng mL-1 for DEP, 5.73 ± 0.31 ng mL-1 and 19.1 ± 1.0 ng mL-1 for DBP and 3.30 ± 0.06 ng mL-1 and 11.0 ± 0.19 ng mL-1 for DEHP, respectively. Good recoveries in the range of 81.89 ± 0.17 to 109.5 ± 2.0% were achieved when the method was used to extract phthalate esters in five instant noodle and two rice soup samples.

Development and investigation of a QuEChERS-based method for determination of phthalate metabolites in human milk.

Phthalates are commonly used as plasticizers and are known as risk factors toward several conditions such as cancer, birth defects, and endocrine disruption. Biomonitoring of phthalates is necessary to assess the potentially harmful effects of long-term exposure. In this work, we have developed a novel QuEChERS method to determine eight phthalate metabolites-mono-(3-carboxypropyl) phthalate, mono-(2-ethyl-5-carboxypentyl) phthalate, mono-(2-ethyl-5-hydroxyhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, mono-n-butyl phthalate, mono-benzyl phthalate, mono-(carboxyloctyl) phthalate, and mono-(carboxynonyl) phthalate-in human milk. The extraction process was optimized by comparing three different QuEChERS methods, and a further purification step was used to eliminate interferential lipid. In this process, several factors, such as the pH based on QuEChERS additive salts, acid dissociation constant, and distribution coefficient of the analyte, were found to have a significant effect on the extraction efficiency of the QuEChERS method. Target compounds were determined using liquid chromatography-tandem mass spectrometry equipped with electrospray ionization in the multiple-reaction monitoring mode. The developed method was verified by evaluating the selectivity, linearity, lower limit of quantification, accuracy, precision, and recovery, and applied to monitor real milk samples from 26 people. It is expected that the established method can be utilized not only to monitor phthalate metabolites in biological samples but also to identify the correlation between phthalate concentrations observed for the mother and the newborn.

New low viscous hydrophobic deep eutectic solvents in vortex-assisted liquid-liquid microextraction for the determination of phthalate esters from food-contacted plastics.

In this work, a novel class of eight low viscosity hydrophobic deep eutectic solvents (DESs) has been designed and prepared from two kinds of quaternary ammonium salts and six kinds of water-insoluble fatty alcohols/acids. Several physical properties of these DESs, such as melting point, density and viscosity, have been determined to investigate their adaptability as solvents. Then, such DESs are used as extraction solvents in a vortex-assisted liquid-liquid microextraction for the extraction and preconcentration of phthalate esters (PEs) from water samples, and the content of PEs from food-contacted plastics is then determined by using gas chromatography. It is found that the analytic method developed in this work exhibits wide linear range of 5-1000 µg L-1, and the limit of detections for target analytes is as low as 1 µg L-1. Finally, the proposed method has been successfully used for the determination of PEs from food-contacted plastics.

A green and simple procedure based on deep eutectic solvents for the extraction of phthalates from beverages.

In this work, a green, inexpensive, simple and fast deep eutectic solvent (DES)-based dispersive liquid-liquid microextraction was evaluated, for the first time, for the extraction of phthalates (i.e. benzylbutyl phthalate, diisobutyl phthalate, diisopentyl phthalate, di-n-pentyl phthalate, di-(2-ethylhexyl) phthalate, di-n-octyl phthalate, diisononyl phthalate, diisodecyl phthalate) from different beverages. Separation and determination were achieved by high performance liquid chromatography-diode-array detection while confirmation was carried out by tandem mass spectrometry. The main factors affecting the extraction such as type and volume of DES and emulsifier, pH and ionic strength, were optimised. Choline chloride:phenol-based DES showed the best results. The methodology was validated for tea, apple-based beverage and pineapple juice. Recovery values ranged from 84 to 120% with relative standard deviation values lower than 11%. Limits of detection of the method were in the range 5.1-14.2 µg L-1 for tea, 5.3-17.8 µg L-1 for apple beverages and 5.9-15.6 µg L-1 for pineapple juices.

Preparation of magnetite/multiwalled carbon nanotubes/metal-organic framework composite for dispersive magnetic micro solid phase extraction of parabens and phthalate esters from water samples and various types of cream for their determination with liquid chromatography.

In the current study, MMWCNTs@MIL-101(Cr) (Fe3O4/multiwalled carbon nanotubes/MIL-101(Cr)) was synthesized and utilized as a new sorbent for the first time. It was employed successfully for the extraction of parabens and phthalate esters (PEs) from water and cream samples prior to their quantification with HPLC-DAD. The prepared metal-organic-framework (MOF) was characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX), EDX mapping, thermogravimetric analysis (TGA), vibrating-sample magnetometer (VSM) and X-ray powder diffraction (XRD). Three phthalate esters (dimethyl phthalate (DMP), diethyl phthalate (DEP), diallyl phthalate (DAP)) and two parabens (methylparaben (MP) and butylparaben (BP)) were chosen as model analytes. Several experimental factors affecting the extraction efficiency, including pH value, nanosorbent amount, sorption time, salt concentration, sample volume, type and volume of the eluent, and elution time were investigated. The optimization of the extraction method was carried out by response surface methodology (RSM) and desirability function (DF) approach. Under the opted conditions, the method was linear in the range of 0.1-1500 µg L-1 with coefficients of determination > 0.9991. The limits of detection of PEs and parabens were found in the range of 0.03-0.15 µg L-1 (S/N = 3). The relative standard deviations were less than 7.5% and the extraction recoveries ranged from 38.04 to 70.62%. The present method was simple, rapid, inexpensive and environmentally friendly and was successfully utilized for the determination of PEs and parabens in water samples and various types of cream samples with satisfactory results.

Simultaneous Determination of Eight Monoalkyl Phthalate Esters in Porcine Tissue by Solid-Phase Extraction and Liquid Chromatography-Tandem Mass Spectrometry.

An improved method for solid-phase extraction (SPE)-liquid chromatography-tandem mass spectrometry was developed to analyze eight monoalkyl phthalate esters (MPEs) in eight different kinds of porcine tissues. The tissue samples were processed using enzymatic deconjugation with ß-glucuronidase, followed by SPE with Oasis MAX cartridges. A pentafluorophenyl column was first used to solve the coeluting issues of MPE isomers. The limits of detection and recoveries were 0.01-0.6 ng/g and 62.5-123.7%, respectively. The intra- and interday precisions were less than 7.1 and 9.4%, respectively. The robust method was successfully applied for the investigation of MPEs in various porcine tissue samples collected from markets in Beijing, China. The occurrence of MPEs with total concentrations of 48.0-108 ng/g was detected, and monoethylhexyl phthalate was the predominant MPE (accounting for 30-57%) in all of the porcine tissue samples. The results will be helpful in assessing the potential risks of diets that include pork.

High-Throughput, Rapid Quantification of Phthalic Acid Esters and Alkylphenols in Fish Using a Coated Direct Inlet Probe Coupled with Atmospheric Pressure Chemical Ionization.

Intake of endocrine-disrupting chemicals (EDCs) by humans could disturb the metabolism of hormones, induce cancer, and damage the liver and other organs. Phthalate acid esters (PAEs) and alkylphenols (APs) are important EDCs and environmental contaminants. With the increasing use of plastics and nonionic surfactants worldwide, PAEs and APs have entered environmental water and accumulated in edible fish, which are finally consumed by humans. In this study, a coated direct inlet probe (CDIP) based on an atmospheric solid analysis probe, which can rapidly and simultaneously extract both PAEs and APs in fish, was developed. Twelve PAEs and APs were quantified by using a stable-isotope-labeled internal standard. Standard curves of the PAEs and APs having correlation coefficients of R2 ≥ 0.9837 were obtained. The limit of detection of the PAEs and APs was distributed from 0.01 to 40 ng g-1. The relative recovery of the method was 78-120% between low, medium, and high spiked levels. Combined with principal component analysis, PAE- and AP-contaminated Carassius auratus from different habitats could be identified. Multiple sample analysis mode allowed the extraction of up to 12 samples at once, and the total analysis time (including sample pretreatment, extraction, and analysis time) was less than 10 min per sample, which indicates that CDIP is useful for rapid quantitative analysis.

Removal of phthalic acid esters from sea buckthorn (Hippophae rhamnoides L.) pulp oil by steam distillation and molecular distillation.

Sea buckthorn (Hippophae rhamnoides L.) pulp oils (SPOs) are rich in a variety of beneficial bioactive ingredients. Nevertheless, SPOs would be exposed to plastic equipment during processing, resulted in increasing phthalates contents and edible risk, as well as affecting oil quality. For these reasons, the effects of two stages steam distillation (SD2) and two stages molecular distillation (MD2) on phthalic acid esters (PAEs) content were investigated and compared in the present work. Compared with SD2, MD2 showed higher removal rates of seven selected PAEs from the SPO. Even if the initial concentration of DBP and DEHP in R-SPO were 1.626 and 10.933 mg/kg respectively, the concentration of DBP and DINP could be reduced below the limit set by China government after treated with MD2. Besides that, there was no trans-fatty acids generated in SPO during the distillation process.