Organophosphate and phthalate esters in standard reference material 2585 organic contaminants in house dust

The levels of 22 phthalate diesters (phthalates) and organophosphate triesters (organophosphates) have been investigated in standard reference material 2585 (SRM 2585) “organic contaminants in house dust.” Ultrasonic-assisted solvent extraction and solid-phase extraction on a Florisil adsorbent were used as the extraction and cleanup steps combined with analysis using gas chromatography–tandem mass spectrometry in positive ion chemical ionization mode. Seven phthalates were detected in the concentration range 1–570 μg/g. Di(2-ethylhexyl) phthalate was the major phthalate present at 570 μg/g. Ten organophosphates were detected in SRM 2585. Tris(2-butoxyethyl) phosphate was the predominant organophosphate at 82 μg/g, and nine organophosphates were determined at concentrations ranging from 0.19 to 2.3 μg/g. Five organophosphates were below the method detection limit, of which two were in level with the procedural blank. The applied extraction and cleanup method was evaluated for the analysis of SRM 2585. The extraction yield was ≥99%, except for tris(2-chloroethyl) phosphate (97%) and diethyl phthalate (98.5%). The problem of calibration curvature is addressed, and it is shown that the use of deuterated standards improves the analysis. The concentrations of ten organophosphate esters were determined in SRM 2585, and seven of these were compared with existing data. To our knowledge, this is the first report of the levels of the seven phthalates esters in SRM 2585 “organic contaminants in house dust.”     

Determination of synthetic musk compounds in indoor house dust by gas chromatography–ion trap mass spectrometry

A new method for the simultaneous determination of 11 synthetic musks and one fragrance compound in house dust was developed. The nitro musks included musk ketone (MK, 4-tert-butyl-3,5-dinitro-2,6-dimethylacetophenone), musk xylene (MX, 1-tert-butyl-3,5-dimethyl-2,4,6-trinitrobenzene), musk ambrette (1-tert-butyl-2-methoxy-4-methyl-3,5-dinitrobenzene) and musk moskene (1,1,3,3,5-pentamethyl-4,6-dinitroindane). The polycyclic musk compounds were 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(γ)-2-benzopyran (HHCB), 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN), 4-acetyl-1,1-dimethyl-6-tert-butylindane, 6-acetyl-1,1,2,3,3,5-hexamethylindane, 5-acetyl-1,1,2,6-tetramethyl-3-isopropylindane, 6,7-dihydro-1,1,2,3,3-pentamethyl-4(5H)-indanon. The one macrocyclic musk was 1,4-dioxacycloheptadecane-5,17-dione. The bicyclic hydrocarbon fragrance compound (1,2,3,4,5,6,7,8-octahydro-2,3,8,8-tetramethylnaphthalen-2yl)ethan-1-one (OTNE) and HHCB-lactone (4,6,6,7,8,8-hexamethyl-1H,3H,4H,6H,7H, 8H-indeno[5,6-c]pyran-1-one), a degradation product of HHCB, were also analysed. NIST SRM 2781 (domestic sludge) and SRM 2585 (organic contaminants in house dust) were analysed for these target compounds. The method was applied for the analysis of 49 paired samples collected using two vacuum sampling methods: a sample of fresh or "active" dust (FD) collected using a Pullman-Holt vacuum sampler, and a household dust (HD) sample taken from the participants' vacuum cleaners. Method detection limits and recoveries ranged from 12 to 48?ng/g and 54 to 117?%, respectively. AHTN, HHCB, OTNE and HHCB-lactone were detected in all samples, with median concentrations of 552, 676, 252 and 453?ng/g for FD samples, respectively; and 405, 992, 212 and 492?ng/g for HD samples, respectively. MX and MK were detected with high frequencies but with much lower concentrations. The two sampling methods produced comparable results for the target analytes. Widely scattered concentration levels were observed for target analytes from this set of 49 house dust samples, suggesting a wide variability in Canadian household exposure to synthetic musks.     

Analysis of 16 phthalic acid esters in food simulants from plastic food contact materials by LC‐ESI‐MS/MS

An RP LC‐ESI‐MS/MS method for the determination of the migration of 16 primary phthalic acid esters from plastic samples has been developed using distilled water, 3% acetic acid, 10% alcohol, and olive oil as food simulants. Detection limits were 1.6–18.5 μg/kg in distilled water, 1.4–17.3 μg/kg in 3% acetic acid, 1.4–19.2 μg/kg in 10% alcohol, and 31.9–390.8 μg/kg in olive oil. The RSDs were in the range of 0.07–11.28%. The real plastic products inspection showed that only few analyzed samples were phthalates contaminated. Bis‐2‐ethylhexyl ester and dibutyl phthalate were the common items migrated from the plastic products into food and feeds, but the migration concentrations were far below the limits set by European Union (1.5 mg/kg for bis‐2‐ethylhexyl ester and 0.3 mg/kg for dibutyl phthalate).     

固相萃取-气相色谱/质谱法同时测定化妆品中的邻苯二甲酸酯和对羟基苯甲酸酯

采用超声协助甲醇提取、固相萃取净化、气相色谱/选择离子质谱联用法,同时测定化妆品中8种邻苯二甲酸酯和4种对羟基苯甲酸酯。该方法线性范围广、重现性好、快速简便、干扰小。样品的加标回收率为80%～100%;含量检测的相对标准偏差小于10%;方法的检出限为0.1~5.0 μg/kg。用该方法对15种实际样品中的12种残留物进行定量检测,结果表明除了一种样品中不含待测物外,其余样品均检测到3~7种待测物。其中以对羟基苯甲酸甲酯、对羟基苯甲酸丙酯、邻苯二甲酸丙酯、邻苯二甲酸环己酯和邻苯二甲酸乙基庚基酯为主。     

Simultaneous screening and determination eight phthalates in plastic products for food use by sonication-assisted extraction/GC-MS methods

Studies on determination of eight kinds of phthalates, e.g. di-ethyl phthalate (DEP), di-propyl phthalate (DPP), di-isobutyl phthalate (DIBP), di-butyl phthalate (DBP), benzyl butyl phthalate (BBP), di-cyclohexyl phthalate (DCHP), di-(2-ethylhexyl) phthalate (DEHP), di-octyl phthalate (DOP), in 25 kinds of plastic products for food use, including packaging bags, packaging film, containers, boxes for microwave oven use, sucking tubes, spoons, cups, plates, etc. by gas chromatography in combination with mass spectrometry detector (GC-MS) in electronic ionisation mode (EI) with selected-ion monitoring (SIM) acquisition method (GC-MS (EI-SIM)) have been carried out. Methods have been developed for both qualitative and quantitative analysis of phthalates. Extraction, clean-up and analysis procedure have been optimized. Determination of samples were performed after frozen in liquid nitrogen and sonication-assisted extraction with hexane, clean-up with LC-C18 SPE and analyzed by GC-MS methods. The base peak (m/z = 149) of all the phthalates was selected for the screening studies. The characteristic ions, 121, 177, 222 for DEP; 191, 209 for DPP; 57, 223 for DIBP; 104 for DBP; 91, 132, 206 for BBP; 55, 167 for DCHP; 113, 167, 279 for DEHP; 279 for DOP were chosen for quantitative studies. These techniques are possible to detect phthalates at the level of 10.0 μg/kg. Overall recoveries were 82-106% with R.S.D. values at 3.8-10.2%. Only one of the 25 examined samples was free from phthalates. The rest 24 samples were found to contain at least three or more of these phthalates. The predominant phthalate detected in the studied samples was DEHP.     

Determination of phthalate esters in bottled water using dispersive liquid–liquid microextraction coupled with GC–MS

Dispersive liquid–liquid microextraction method was developed for the determination of the amount of phthalate esters in bottled drinking water samples and dispersive liquid–liquid microextraction samples were analyzed by GC–MS. Various experimental conditions influencing the extraction were optimized. Under the optimized conditions, very good linearity was observed for all analytes in a range between 0.05 and 150 μg/L with coefficient of determination (R²) between 0.995 and 0.999. The LODs based on S/N = 3 were 0.005–0.22 μg/L. The reproducibility of dispersive liquid–liquid microextraction was evaluated. The RSDs were 1.3–5.2% (n = 3). The concentrations of phthalates were determined in bottled samples available in half shell. To understand the leaching profile of these phthalates from bottled water, bottles were exposed to direct sunlight during summer (temperature from 34–57°C) and sampled at different intervals. Result showed that the proposed dispersive liquid–liquid microextraction is suitable for rapid determination of phthalates in bottled water and di‐n‐butyl, butyl benzyl, and bis‐2‐ethylhexyl phthalate compounds leaching from bottles up to 36 h. Thereafter, degradation of phthalates was observed.     

A novel quantitation method for phthalates in air using a combined thermal desorption/gas chromatography/mass spectrometry application

In this study, a novel quantitation method was developed to facilitate the simple and effective sampling and analysis of phthalates in air based on a sorbent tube-thermal desorption-gas chromatography-mass spectrometry system combination. The performance of the thermal desorption-based analysis was assessed using three different sorbent combinations [1]: quartz wool (QW) [2], glass wool (GW), and [3] quartz wool plus Tenax TA (QWTN) in terms of relative recovery in reference to a direct injection method. There was no significant difference in the average recovery rate for seven target phthalates based on sorbent tube type (QW, 70.2 ± 4.28; GW, 73.2 ± 8.8; and QWTN, 72.5 ± 5.02%). However, the recovery rate of phthalates in each sorbent tube type was distingusihed by physicochemical properties of the target compound (e.g., molecular weight and boiling point). The recovery rate of the QW tube was high for dimethyl phthalate and diethyl phthalate compared to other sorbent tubes, while that of the GW tube exhibited greater values for dibutyl phthalate, benzyl butyl phthalate, di(2-ethylhexyl) adipate, di(2-ethylhexyl) phthalate, and di-n-octyl phthalate. The simple sorbent tube-thermal desorption approach is feasible for the quantitation of seven phthalates present at 0.45–24.5 ng m⁻³ levels in actual air samples (20 L).     

Pitfalls and Solutions for the Trace Determination of Phthalates in Water Samples

A method based on liquid-liquid extraction (LLE) and automated large volume injection (LVI)-GC-MS analysis was developed for the trace determination of phthalate di-esters in water samples at sub-g L^–1 (ppb) levels. Strategies applied to reduce contamination include (i) careful selection of tools, glassware and solvents, (ii) systematic blank checks of the chromatographic system, glassware and solvents and (iii) frequent verifications of blanks during sequences. Background levels could be reduced to those present in the extraction solvent. For phthalates not present in the extraction solvent the limits of quantitation (LOQ) are 6 ng L^–1 for di-methyl phthalate (DMP), 3 ng L^–1 for benzylbutyl phthalate (BzBP) and 45 ng L^–1 for the isomeric phthalate mixtures di-isononyl phthalate (DiNP) and di-isodecyl phthalate (DiDP). For the other phthalates, the LOQ was set at twice the blank (extraction solvent) level and are 20 ng L^–1 for di-ethyl phthalate (DEP), 60 ng L^–1 for di-isobutyl phthalate (DiBP), 80 ng L^–1 for di-n-butyl phthalate (DBP) and 30 ng L^–1 for bis-(2-ethylhexyl) phthalate (DEHP).Dedicated to Professor K. Jinno on the occasion of his 60^th birthday     

Determination of phthalates and adipate in bottled water by headspace solid-phase microextraction and gas chromatography/mass spectrometry

The performance of three fibres for the headspace solid-phase microextraction (SPME) of di-2-ethylhexyl adipate (DEHA) and eight phthalates in water was investigated systematically under different extraction conditions. Good responses on the 65 microm polydimethylsiloxane/divinylbenzene (PDMS/DVB) SPME fibre were observed for DEHA and all phthalates. The polydimethylsiloxane (PDMS) SPME fibre had very poor responses for the lighter and slightly polar phthalates, dimethyl phthalate (DMP) and diethyl phthalate (DEP), while the divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) SPME fibre had very poor responses for the heavier and non-polar adipate and phthalates. The salt (NaCl) was found to increase the partitioning of DMP, DEP, diisobutyl phthalate (DiBP), di-n-butyl phthalate, and benzyl butyl phthalate (BBP) from water into the headspace, while partitioning of heavier adipate and phthalates from water into headspace was suppressed when the concentration of NaCl was above 10%. The automated headspace SPME methods were developed and validated under two different salting conditions (30% NaCl for DMP, DEP and BBP, and 10% for DEHA, DiBP, DBP, di-n-hexyl phthalate (DHP), di-2-ethylhexyl phthalate (DEHP), and di-n-octyl phthalate (DOP)). Linearity with R(2) values better than 0.9949 was observed for DEHA and eight phthalates over the range from 0.1 to 20 microg L(-1). Method detection limits ranged from 0.003 microg L(-1) for DOP to 0.085 microg L(-1) for BBP. Good repeatability was observed for DEHA and most phthalates with relative standard deviation (RSD) values less than 10%. The methods were used to analyse bottled water samples for DEHA and eight phthalates. DMP, DHP, BBP, DEHA and DOP were not detected in any samples. Concentrations of the other phthalates were low (around sub-ppb) except for DBP in the water from a polycarbonate bottle at 1.72 microg L(-1).     

Determination of phthalates in beverages using multiwalled carbon nanotubes dispersive solid‐phase extraction before HPLC–MS

A microdispersive solid‐phase extraction method has been developed using multiwalled carbon nanotubes of 110–170 nm diameter and 5–9 μm length for the extraction of a group of nine phthalic acid esters (i.e., bis(2‐methoxyethyl) phthalate, bis‐2‐ethoxyethyl phthalate, dipropyl phthalate, butylbenzyl phthalate, bis‐2‐n‐butoxyethyl phthalate, bis‐isopentyl phthalate, bis‐n‐pentyl phthalate, dicyclohexyl phthalate, and di‐n‐octyl phthalate) from tap water as well as from different beverages commercialized in plastic bottles (mineral water, lemon‐ and apple‐flavored mineral water, and an isotonic drink). Determination was carried out by high‐performance liquid chromatography coupled to mass spectrometry. The extraction procedure was optimized following a step‐by‐step approach, being the optimum extraction conditions: 50 mL of each sample at pH 6.0, 80 mg of sorbent, and 25 mL of acetonitrile as elution solvent. To validate the methodology, matrix‐matched calibration and a recovery study were developed, obtaining determination coefficients >0.9906 and absolute recovery values between 70 and 117% (with relative standard deviations < 17%) in all cases. The limits of quantification of the method were between 0.173 and 1.45 μg/L. After the evaluation of the matrix effects, real samples were also analyzed, finding butylbenzyl phthalate in all samples (except in apple‐flavored mineral water), though at concentrations below its limit of quantification of the method.     

Development of a solid-phase microextraction method for the determination of phthalic acid esters in water

Solid-phase microextraction method (SPME) coupled to GC/ECD has been developed and validated for the determination of phthalic acid esters (dimethyl-, diethyl-, di-n-butyl-, butylbenzyl-, di-2-ethylhexyl- and di-n-octyl phthalate) in water samples. Two types of coatings (PDMS, PA), altogether four different kinds of fibers have been investigated. Both parameters affecting the partition of analytes between a fiber coating and aqueous phase (i.e. extraction time, extraction temperature, agitation) and conditions of the thermal desorption in a GC injector were optimized. The final SPME method employing the polyacrylate fiber, extraction time 20 min, heating and stirring of the sample enabled the determination of all six phthalates in water samples. The method showed linear response over four orders of magnitude and the limits of quantification of the method ranged between 0.001 and 0.050 μg l⁻¹. The repeatability expressed as R.S.D. was in the range 4-10% for the spiking level 7 μg l⁻¹ of each analyte. The applicability of the developed SPME method was demonstrated for real water samples.     

Occurrence of endocrine-disrupting compounds in reclaimed water from Tianjin,China

Continuous disposal of endocrine-disrupting compounds (EDCs) into the environment can lead to serious human health problems and can affect plants and aquatic organisms. The determination of EDCs in water has become an increasingly important activity due to our increased knowledge about their toxicities, even at low concentration. The EDCs in water samples from the reclaimed water plant of Tianjin, northern China, were identified by gas chromatography (GC)–mass spectrometry (MS). Important and contrasting EDCs including estrone (E1), 17β-estradiol (E2), 17α-ethynylestradiol (EE2), 4-tert-octylphenol (OP), 4-nonylphenol (NP), bisphenol A (BPA), di-n-butyl phthalate (DnBP), diisobutyl phthalate (DIBP), and di(2-ethylhexyl)phthalate (DEHP) were selected as the target compounds. Concentrations of steroid hormones, alkylphenolic compounds and phthalates ranged from below the limit of detection (LOD) to 8.1 ng L⁻¹, from <LOD to 14.2 ng L⁻¹, and from 1.00 μg L⁻¹ to 23.8 μg L⁻¹, respectively. The average removal efficiencies for target EDCs varied from 30% to 82%. These results indicate that environmental endocrine disrupting compounds are not completely removed during reclaimed water treatment and may be carried over into the general aquatic environment.     

Simultaneous determination of 22 phthalate esters in polystyrene food‐contact materials by ultra‐performance convergence chromatography with tandem mass spectrometry

A method for the determination of 22 phthalate esters in polystyrene food‐contact materials has been established using ultraperformance convergence chromatography with tandem mass spectrometry. In this method, 22 phthalate esters were analyzed in <3.5 min on an ACQUITY Tours 1‐AA column by gradient elution. The mobile phase, the compensation solvent, the flow rate of mobile phase, column temperature, and automatic back pressure regulator pressure were optimized, respectively. There was a good linearity of 20 phthalate esters with a range of 0.05–10 mg/L, diisodecyl phthalate and diisononyl phthalate were 0.25–10 mg/L, and the correlation coefficients of all phthalates were higher than 0.99 and those of 16 phthalates were higher than 0.999. The limits of detection and the limits of quantification of 15 phthalates were 0.02 and 0.05 mg/kg, meanwhile diallyl phthalate, diisobutyl phthalate, dimethyl phthalate, di‐n‐butyl phthalate, and di(2‐ethylhexyl) phthalate were 0.05 and 0.10 mg/kg, and diisodecyl phthalate and diisononyl phthalate were 0.10 and 0.25 mg/kg. The spiked recoveries were in the range of 76.26–107.76%, and the relative standard deviations were in the range of 1.78–12.10%. Results support this method as an efficient alternative to apply for the simultaneous determination of 22 phthalate esters in common polystyrene food‐contact materials.     

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

Novel superparamagnetic chitosan-coated C₁₈-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 1,000 were 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.     

Determination of phthalate esters in Chinese spirits using isotope dilution gas chromatography with tandem mass spectrometry

Phthalate esters are additives used in polyvinylchloride and are found as contaminants in many food products. An isotope dilution mass spectrometry technique has been developed for accurate analysis of 16 phthalate esters in Chinese spirits by adopting the 16 corresponding isotope‐labeled phthalate esters. The ethanol in the spirit sample was first removed by heating with a water bath at 100°C with a stream of nitrogen, after which the residue was extracted with n‐hexane twice. The phthalates collected were identified and quantified by gas chromatography with tandem mass spectrometry in multiple reaction monitoring mode. The spiking recoveries of 16 analytes ranged from 94.3 to 105.3% with relative standard deviation values of <6.5%. The detection limits for 16 analytes were <10.0 ng/g. The expanded relative uncertainties were from 3.0 to 14%. A survey was performed on Chinese spirits from the market. Six of the nine analyzed samples were contaminated by phthalates. Di‐n‐butyl phthalate and di‐2‐ethylhexyl phthalate showed higher detection frequency and concentrations. This isotope dilution gas chromatography with tandem mass spectrometry method is simple, rapid, accurate, and highly sensitive, which qualifies as a candidate reference method for the determination of phthalates in spirits.     

Simple and rapid determination of phthalates using microextraction by packed sorbent and gas chromatography with mass spectrometry quantification in cold drink and cosmetic samples

A simple and rapid method using microextraction by packed sorbent coupled with gas chromatography and mass spectrometry has been developed for the analysis of five phthalates, namely, diethyl phthalate, benzyl‐n‐butyl phthalate, dicyclohexyl phthalate, di‐n‐butyl phthalate, and di‐n‐propyl phthalate, in cold drink and cosmetic samples. The various parameters that influence the microextraction by packed sorbent performance such as extraction cycle (extract–discard), type and amount of solvent, washing solvent, and pH have been studied. The optimal conditions of microextraction using C₁₈ as the packed sorbent were 15 extraction cycles with water as washing solvent and 3 × 10 μL of ethyl acetate as the eluting solvent. Chromatographic separation was also optimized for injection temperature, flow rate, ion source, interface temperature, column temperature gradient and mass spectrometry was evaluated using the scan and selected ion monitoring data acquisition mode. Satisfactory results were obtained in terms of linearity with R² >0.9992 within the established concentration range. The limit of detection was 0.003–0.015 ng/mL, and the limit of quantification was 0.009–0.049 ng/mL. The recoveries were in the range of 92.35–98.90% for cold drink, 88.23–169.20% for perfume, and 88.90–184.40% for cream. Analysis by microextraction by packed sorbent promises to be a rapid method for the determination of these phthalates in cold drink and cosmetic samples, reducing the amount of sample, solvent, time and cost.     

Simultaneous determination of phthalates and adipates in human serum using gas chromatography–mass spectrometry with solid‐phase extraction

A gas chromatography–mass spectrometry assay was developed and validated for the simultaneous determination of phthalates and adipates in human serum. The phthalates and adipates studied were dimethyl phthalate, diethyl phthalate, dibutyl phthalate, benzylbutyl phthalate, di‐2‐ethylhexyl phthalate, di‐n‐octyl phthalate, diethyl adipate, dibutyl adipate, diisobutyl adipate, bis(2‐butoxyethyl) adipate and di‐2‐ethylhexyl adipate, with diisooctyl phthalate as internal standard. The extraction and cleaning up procedure was carried out with solid‐phase extraction cartridges containing dimethyl butylamine groups, which showed extraction efficiencies over 88% for each analyte and the internal standard. The calibration curves obtained were linear with correlation coefficients greater than 0.98. For all analytes, the assay gave CV% values for intra‐day precision from 4.9 to 13.3% and mean accuracy values from 91.4 to 108.4%, while inter‐day precision was 5.2–13.4% and mean accuracy 91.0–110.2%. The limits of detection for the assay of phthalates and adipates were in the range 0.7–4.5 ng/mL. The method is simple, sensitive and accurate, and allows for simultaneous determination of nanogram levels of phthalates and adipates in human serum. It was successfully applied to an investigation on the level of phthalates and adipates in a non‐occupationally exposed population.     

Nanostructured gemini‐based supramolecular solvent coupled with ultrasound‐assisted back extraction as a preconcentration step before GC–MS

Liquid‐phase microextraction based on gemini‐based supramolecular solvent was successfully applied as a preconcentration step before gas chromatography with mass spectrometry. To eliminate the interferences of gemini surfactant, the analytes were back‐extracted into an immiscible organic solvent in the presence of ultrasonic sound waves. Three phthalate esters (di‐n‐butyl‐, butylbenzyl‐, bis(2‐ethylhexyl)‐, and di‐n‐octyl phthalatic esters) were used as target analytes. The effective parameters on extraction efficiency of the target analytes (i.e., the amount of surfactant and volume of propanol as major components making up the supramolecular solvent, ionic strength, hexane volume, and ultrasound time) were investigated and optimized by a one‐variable‐at‐a‐time method. Under the optimum conditions, the preconcentration factors of the analytes were in the range of 95–182. The linear dynamic range of 0.05–200.00 μg/L with a correlation of determination of (R ²) ≥ 0.9935 was obtained. The proposed method had an excellent limit of detection (S/N = 3) of 0.01 for di‐n‐octyl and 0.02 μg/L for butylbenzyl‐ and di‐n‐butyl‐phthalatic ester. Good relative recoveries in the range of 85.7–105.2% guaranteed the accuracy of the amount of phthalates distinguished in the nonspiked samples.     

Microwave‐assisted preparation of poly(ionic liquids)‐modified polystyrene magnetic nanospheres for phthalate esters extraction from beverages

The fabrication of novel poly(ionic liquids)‐modified polystyrene (PSt) magnetic nanospheres (PILs‐PMNPs) by a one‐pot miniemulsion copolymerization reaction was achieved through an efficient microwave‐assisted synthesis method. The morphology, structure, and magnetic behavior of the as‐prepared magnetic materials were characterized by using transmission electron microscopy, vibrating sample magnetometry, etc. The magnetic materials were utilized as sorbents for the extraction of phthalate esters (PAEs) from beverage samples followed by high‐performance ultrafast liquid chromatography analysis. Significant extraction parameters that could affect the extraction efficiencies were investigated particularly. Under optimum conditions, good linearity was obtained in the concentration range of 0.5–50 (dimethyl phthalate), 0.3–50 (diethyl phthalate), 0.2–50 (butyl benzyl phthalate), and 0.4–50 μg/L (di‐n‐butyl phthalate), with correlation coefficients R ² > 0.9989. Limits of detection were in the range 125–350 pg. The proposed method was successfully applied to determine PAEs from beverage samples with satisfactory recovery ranging from 77.8 to 102.1% and relative standard deviations ranging from 3.7 to 8.4%. Comparisons of extraction efficiency with PSt‐modified MNPs as sorbents were performed. The results demonstrated that PILs‐PMNPs possessed an excellent adsorption capability toward the trace PAE analytes.     

Coating of optical fiber with a smart thermosensitive polymer for the separation of phthalate esters by solid‐phase microextraction

A solid‐phase microextraction fiber was prepared by coating an optical fiber with a temperature‐sensitive polymer to determine phthalate esters. N‐Isopropylacrylamide and N,N′‐methylenebisacrylamide were used as the monomer and the cross linker, respectively. The fabricated fiber was characterized by FTIR spectroscopy, thermogravimetric analysis, and scanning electron microscopy. During extraction, important factors such as extraction time, pH, temperature, and ionic strength were optimized. The fabricated fiber, which is firm, inexpensive, stable, and efficient, is a vital material used in solid‐phase microextraction. Under optimum conditions, the calibration curve was linear and in the range of 1–20 μg/L (r² = 0.9747). The high extraction efficiency was obtained for phthalates with a detection limit of 0.12 μg/L. The fabricated fiber was successfully applied to the solid‐phase micro extraction of phthalates from water samples after its extraction, followed by gas chromatography with flame ionization detection.