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In an attempt to enhance the adsorptive properties while addressing the limitations associated with powdered nature, zeolitic imidazolate framework (ZIF-67)-derived cobalt-doped nanoporous carbon (Co-NPC) was incorporated into chitosan and then shaped like hollow fiber by a simple casting method. Further modification with polyaniline (PANI) was also performed to improve extraction efficacy. The applicability of the modified hollow fibers was then investigated by packing them into a cartridge and utilizing them for conducting hollow fibers-packed in-cartridge micro solid-phase extraction (HF-IC µ-SPE) of parabens including methylparaben (MP), ethylparaben (EP), and propylparaben (PP) from human breast milk samples. Factors affecting extraction performance were studied using central composite design (CCD). Under the optimal conditions, good linearity was achieved within the range of 0.5-500 μg L -1 with the determination coefficient (R 2 ) higher than 0.9901. All analytical parameters were obtained by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. In this regard, the limits of detection values (LODs) were 0.5 to 1.0 μg L -1 . Intra- and inter-assay precision RSDs % were lower than 7.9 % and 8.4 %, respectively. Relative recoveries of breast milk samples were found in the range of 88.0-109.5 %. Accordingly, the novel nanocomposite sorbent based on PANI@Co-NPC/Chitosan hollow fiber was found to be an efficient, simple, and cost-effective packing material for HF-IC µ-SPE. It can also be offered as a promising alternative adsorbent to coated conventional hollow fiber., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

An eco-friendly method for the determination of sweeteners (aspartame, acesulfame-K) and preservatives (benzoic acid, sorbic acid, methylparaben, ethylparaben) in functional beverages and flavoured waters using thin film microextraction (TFME) and high-performance liquid chromatography with UV detection (HPLC-UV) was proposed. A series of fourteen green and renewable solidified natural deep eutectic solvents (NADESs) were prepared and tested as 'eutectosorbents' in TFME for the first time. In the proposed method, the NADES containing acetylcholine chloride and 1-docosanol at a 1:3 molar ratio was finally chosen to coat a support. Four factors, i.e., the mass of the NADES, pH of the samples, extraction time, and desorption time, were tested in the central composite design to select the optimal TFME conditions. Limits of detection were equal to 0.022 µg mL -1 for aspartame, 0.020 µg mL -1 for acesulfame-K, 0.018 µg mL -1 for benzoic acid, 0.026 µg mL -1 for sorbic acid, 0.013 µg mL -1 for methylparaben, and 0.011 µg mL -1 for ethylparaben. Satisfactory extraction recoveries between 82% and 96% were achieved with RSDs lower than 6.1% (intra-day) and 7.4% (inter-day). The proposed 'eutectosorbent' presented good stability that enabled effective extractions for 16 cycles with recovery of at least 77%. The proposed NADES-TFME/HPLC-UV method is highly sensitive and selective. However, the use of a solid NADES as a sorbent, synthesized without by-products, without the need for purification, and with good stability on a support with the possibility of reusability increases the ecological benefit of this method. The greenness aspect of the method was evaluated using the Complex modified Green Analytical Procedure Index protocol and is equal to 84/100.

Gas flow-assisted dispersive liquid-phase microextraction based on deep eutectic solvent was used to determine parabens in personal care products such as mouthwash, lidocaine gel, aloe vera gel, and skin tonic. A homemade extraction device was innovated, in which by passing the stream of gas bubbles through the deep eutectic solvent a thin layer of the extraction phase is coated on the surface of the bubbles. The extraction is finally achieved when the bubbles are going up through the sample. The single-factor experiments and response surface methodology were applied to optimize the independent variables. The linear range of the method was 0.5 to 1000 µg L -1 , the coefficient of determination for the goal analytes was higher than 0.9989, the instrumental limit of detections were in the range 0.2-0.3 μg L -1 , and the instrumental limit of quantifications were in the range 0.5-1.1 μg L -1 , the relative standard deviations were <5.2% for repeatability and <11.2% for intermediate precision, and the enrichment factors were 66 to 87 obtained under the optimized conditions. A spiking approach by means of standard material was used to estimate accuracy. The relative recoveries were in the range 95.8-105.2%. By using mentioned strategies, the organic waste and energy consumption reduced, toxic reagents replaced with safer ones, and operator safety enhanced. Accordingly, these benefits have been simultaneously attained and, the proposed method was one step closer to automation and sustainable analytical chemistry., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Although parabens are useful due to their antiseptic properties, their widespread use has caused concerns regarding their potential toxicological effects. In this study, a novel magnetic solid-phase extraction combined with ultra-high-performance liquid chromatography-tandem mass spectrometry (MSPE-UHPLC-MS/MS) was developed, based on ordered magnetic mesoporous carbon (MMC), for paraben analysis. The MMC was prepared by soft-template synthesis, with a unique pore structure and a highly specific surface response, indicating potential as an excellent adsorbent. Several parameters affecting the paraben extraction efficiency were investigated and a novel method for paraben analysis in serum and urine samples using MSPE-UHPLCMS/MS was developed. The concentrations of methylparaben, ethylparaben, isopropylparaben, and propylparaben in these samples were 0.0380-4.36, 0.460-9.65, 0.0118-0.770, and 0.0363-0.641 μg/L, respectively, whereas isobutylparaben and butylparaben were not detected. Furthermore, satisfactory recoveries of 76.4-121% with relative standard deviations (n = 5) of 1.9-8.6% were obtained. Therefore, the developed MSPE-UHPLC-MS/MS method was efficient, highly sensitive, and reliable for analysing parabens in complex biological samples., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Although Australia is the largest exporter of faba bean globally, there is limited information available on the levels of bioactive compounds found in current commercial faba bean varieties grown in this country. This study profiled the phenolic acid and flavonoid composition of 10 Australian faba bean varieties, grown at two different locations. Phenolic profiling by HPLC-DAD revealed the most abundant flavonoid to be catechin, followed by rutin. For the phenolic acids, syringic acid was found in high concentrations (72.4-122.5 mg/kg), while protocatechuic, vanillic, p -hydroxybenzoic, chlorogenic, p -coumaric, and trans-ferulic acid were all found in low concentrations. The content of most individual phenolics varied significantly with the variety, while some effect of the growing location was also observed. This information could be used by food processors and plant breeders to maximise the potential health benefits of Australian-grown faba bean.

An improved fabric-phase sorptive extraction (FPSE) protocol has been developed and validated herein for the simple, fast, sensitive and green determination of seven parabens-methyl paraben, ethyl paraben, propyl paraben, butyl paraben, isopropyl paraben, isobutyl paraben and benzyl paraben-in human urine samples by HPLC-DAD. The mobile phase consisted of ammonium acetate (0.05 m) and acetonitrile, while total analysis time was 13.2 min. Sol-gel poly (tetrahydrofuran) coated FPSE membrane resulted in optimum extraction sensitivity for the seven parabens. The novel FPSE medium as well as the improved and faster sample preparation procedure resulted in lower limit of detection and quantitation values in comparison with previously reported methods. The separation was carried out using an RP-HPLC method with a Spherisorb C 18 column and a flow rate of 1.4 ml/min. The validation of the analytical method was carried out by means of linearity, precision, accuracy, selectivity, sensitivity and robustness. For all seven parabens, the limits of detection and quantitation were 0.003 and 0.01 μg/ml, respectively. Relative recovery rates were between 86.3 and 104%, while RSD values were <12.6 and 19.3% for within- and between-day repeatability, respectively. The method was subsequently applied to real human urine samples., (© 2020 John Wiley & Sons, Ltd.)

A visual, rapid, and sensitive micro-solid phase extraction method was developed for the detection of p-hydroxybenzoic acid using molecularly imprinted chitosan microspheres based on deep eutectic solvents, both as a functional monomer and template. The parameters were optimized by using the response surface methodology strategy. The extraction capacity of p-hydroxybenzoic acid from pear rind under the optimized conditions using response surface methodology was 46.32 mg/g, when the pH of the extract solution (2), extraction time (35 min), extraction temperature (30°C), and adsorbent dosage (2 mg). The molecularly imprinted chitosan microspheres produced higher selectivity and extraction capacity than the traditional materials., (© 2020 Wiley-VCH GmbH.)

Two new compounds, named ordosacid A ( 5 ) and ordosacid B ( 6 ), along with four known compounds: 3,4-dihydroxybenzaldehyde ( 1 ), p -hydroxybenzoic acid ( 2 ), p -hydroxycinnamic acid ( 3 ) and o -hydroxycinnamic acid ( 4 ), were isolated from the ethyl acetate extract of Artemisia ordosica Krasch. The structures of new compounds were elucidated on the basis of spectroscopic methods including UV, IR, ESI-MS, 1D NMR, 2D NMR, HR-ESI-MS and modified Mosher's method.

In sample pre-treatment, millifluidic electromembrane platforms have been developed to extract and pre-concentrate target molecules with good clean-up that minimize matrix effects. Optimal operation conditions are normally determined experimentally, repeating the extractions at different conditions and determining the efficiencies by an analytical technique. To shorten and simplify the optimization protocol, millifluidic platforms have been electrically characterized by impedance spectroscopy. The magnitude of the resistance of the electromembrane has been found very predictive of the migration capacity and extraction efficiency of three different parabens on real time. The optimal conditions (4 V of applied potential) (Electromembrane extraction low voltage) have been successfully applied in the extraction of parabens from urine samples, that not only improves the extraction efficiency (100% for all compounds) but also provides a very low current intensity (7 µA), which is very important in electromembrane to minimize electrolysis phenomena. The possibility to optimize one of the most critical and important parameters such as the voltage with a simple electrical model may accelerate the production of application-specific millifluidic electromembrane platforms in a short development time. The results showed that millifluidic electromembrane extraction based low voltage has a future potential as a simple, selective, and time-efficient sample preparation technique allowing a simple battery as power supply., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A novel magnetic organic porous polymer (denoted as Fe 3 O 4 @PC-POP) was developed for magnetic solid-phase extraction (MSPE) of two gastric cancer biomarkers (P-cresol and 4-hydroxybenzoic acid) from urine samples prior to high-performance liquid chromatographic analysis. The adsorbent was characterized by scanning electron microscope, transmission electron microscope, FTIR, powder X-ray diffraction, and other techniques. The result of dynamic light scattering shows that the particle size of the adsorbent is mainly distributed around 400 nm. Based on the design concept of the Fe 3 O 4 @PC-POP, the proposed material can effectively capture the target analytes through electrostatic and hydrophobic interaction mechanism. Furthermore, the enrichment conditions were optimized by the response surface method, and the method was utilized for the determination of P-cresol and 4-hydroxybenzoic acid in real urine samples from health and gastric cancer patients with high enrichment factors (34.8 times for P-cresol and 38.7 times for 4-hydroxybenzoic acid), low limit of detection (0.9-5.0 μg L -1 ), wide linear ranges (3.0-1000 μg L -1 ), satisfactory relative standard deviation (2.5%-8.5%), and apparent recoveries (85.3-112% for healthy people's and 86.0-112% for gastric cancer patients' urine samples). This study provides a guided principle for design of the versatile polymer with specific capturing of the target compounds from complex biological samples. Graphical abstract.

For a wide variety of hydrophilic interaction chromatography stationary phases, a repeatable partial equilibration was demonstrated in gradient elution after purging with as little as 12 column volumes of mobile phase. Relative standard deviations of retention time of on average ~0.15% could be obtained after 1 or 2 conditioning (blank) runs. The equilibration period must be kept strictly constant, otherwise selectivity changes occur, but this is not problematic on modern instruments. Partial equilibration was largely independent of stationary phase or gradient slope. Alternatively, full column equilibration is favoured for stationary phases that do not trap extensive water layers, and for materials with a wider pore size that have a lower surface area. Temperatures somewhat above ambient also shorten the equilibration time. Some stationary phases under optimum conditions can achieve full column equilibration using purging with ~12 column volumes, which is useful for rapid set-up of isocratic separations or for conventional gradient analysis., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest in this work., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In this work, a novel, rapid, and simple analytical method was proposed for the detection of parabens in milk sample by gas chromatography coupled with mass spectrometry. At the same time, milk sample was pretreated by magnetic solid phase extraction, which detected up to five parabens. A series of important parameters of magnetic solid phase extraction were investigated and optimized, such as pH value of loading buffer, amount of material, adsorption time, ionic strength, eluting solvents, and eluting time. Under the optimized conditions, the corresponding values were more than 0.9991, limits of detection and the limit of quantification were 0.1 and 0.5 ng/mL, respectively. In addition, the recoveries were achieved in range of 95-105%, the liner range were within 0.1-600 ng/mL, and the relative standard deviations were even lower than 5%., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

In the current study, MMWCNTs@MIL-101(Cr) (Fe 3 O 4 /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., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Bar adsorptive microextraction using polyimide (PI) particles as the extraction phase followed by thermal desorption and gas chromatography-mass spectrometry (BAμE/TD-GC-MS) was developed to detect parabens in condiments, such as soy sauce, vinegar, and cooking wine. The PI particles were prepared by pneumatic spray combined with the immersion-precipitation phase transformation method. The prepared particles have highly porous surfaces, on which the 10-60 nm open nanopores are closely packed. Particles between 250-500 μm were then sieved out and used as extraction phase for BAμE. In contrast to the smooth and dense surface of the conventional PI phase transformation bar, the macroscopic rough surface of the PI particle bar and its microscopic porous particle surfaces provided larger extraction interfaces and more surface adsorption sites, both of which enhanced the extraction mass flux. With an extraction time of 2 min, the absolute recoveries of parabens by the PI particle bar were 1.9˜2.7 times those obtained by the conventional PI phase transformation bar. The intrabatch and interbatch precisions of the PI particle bars were less than 4.6% and 7.5%, respectively, and the PI particle bar exhibited a long lifetime of more than 50 extraction/desorption cycles. To realize rapid determination of parabens, the extraction time was fixed at 2 min. The analytical performance for standard water samples showed wide linearity (0.14-50 μg/L) with good correlation coefficients (r > 0.9980), good precision (RSD < 5.6%), appropriate detection limits (0.005-0.008 μg/L), and high enrichment factors (305-626). For the analysis of parabens in diluted condiments, the relative recoveries were between 86.1% and 109.0% with RSDs ranging from 0.1%-8.7%., (Copyright © 2019 Elsevier B.V. All rights reserved.)

This work describes a new, fast and sensitive method for the simultaneous determination of seven paraben residues including methyl paraben (MPB), ethyl paraben (EPB), propyl paraben (PPB), isopropyl paraben (iPPB), butyl paraben (BPB), isobutyl paraben (iBPB) and benzyl paraben (BzPB) in human whole blood, plasma and urine. The analytes were extracted from the biological matrices by an innovative technique, fabric phase sorptive extraction (FPSE) and subsequently analyzed by high-performance liquid chromatography (HPLC) coupled with photo diode array detector (PDA). The separation was carried out with a Spherisorb C18 column using methanol and phosphate buffer as mobile phases. Ketoprofen was used as the internal standard (IS). The analytical method has been validated according to the International Guidelines in terms of calibration curves for each biological matrix, precision (intra and inter day), trueness, selectivity, LODs, LOQs and ruggedness. Subsequently, the performance of the analytical method was evaluated on real biological samples. The proposed innovative method allows simultaneous analysis of seven paraben residues in three different biological matrices, including whole blood, plasma and urine and therefore it is easily applicable to monitor these substances in different biological samples. Furthermore, extraction technique used in this work is fast, easy to use and in accordance with the modern green analytical chemistry (GAC) principles., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In the present study, an electrospun composite of polyamide-graphene oxide-polypyrrole was synthesized. The characterization of the synthesized material was accomplished using field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FT-IR). FESEM images showed uniform and beadles nanofibers. The composite was employed as a novel sorbent for spin-column micro solid phase extraction to determine parabens in milk samples. Addition of graphene oxide and polypyrrole into the polymeric network of polyamide significantly improves the extraction efficiency of the electrospun sorbent due to providing the possibility of various interactions with the target analytes such as hydrogen bonding, hydrophobic and π-π stacking. All effective parameters on the efficiency of both adsorption and desorption steps were optimized. These parameters were pH of sample solution (5.0), sorbent amount (20 mg), type and volume of desorption solvent (200 μL of methanol), number of cycles (7 and 14) and centrifugation speed (600 and 500 rpm) of both adsorption and desorption steps. Under the optimal conditions, the calibration plots were linear within the range of 10-1000, 15-1000, and 20-1000 ng mL -1 for methyl paraben, ethyl paraben and propyl paraben, respectively. Limits of detection were obtained lower than 7.0 ng mL -1 by HPLC-UV. Intra- and inter-assay relative standard deviations were less than 8.6% and 5.8%, respectively. Finally, the method was successfully applied for determination of parabens in some milk samples and good recoveries were obtained within the range of 81.7-97.8%. The results demonstrated good efficiency of the synthesized electrospun composite nanofibers as the packing material for spin-column micro solid phase extraction., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Magnetic hydroxyapatite nanoparticles (γ-Fe 2 O 3 @HAP) are shown to be a viable sorbent for the preconcentration and adsorption of parabens (specifically of methyl-, ethyl-, propyl-, butyl-, pentyl-, phenyl- and benzylparaben). The average diameter of the magnetic γ-Fe 2 O 3 @HAP nanoadsorbents is 25 nm. The effects of amount of nanoadsorbent, pH value and time of adsorption on the adsorption efficiency were studied by chemometry and optimized using a Box-Behnken design, and the respective response surface equations were derived. The loaded magnetic nanoadsorbent can be removed from the aqueous sample by applying an external magnetic field. Following extraction with acetonitrile, the parabens were quantified by gas chromatography with mass spectrometric detection. Under optimum condition, the limit of detection (LOD) and adsorption efficiencies of the method are in the range from 5 to 10 μg L -1 and 95-106%, respectively. The preconcentration factors range from 320 to 350. The results demonstrate that this nanoadsorbent can be applied to the removal of parabens from different water, soil, beverage and urine samples. Graphical abstract Schematic representation of ultrasound-assisted solid-phase extraction of parabens from environmental and biological samples by γ-Fe 2 O 3 @HAP nanoadsorbent as a new and effective method with high reproducibility and reusability.

A novel supramolecular solvent (SUPRAS) based on hexafluoroisopropanol (HFIP)/Brij-35 was proposed for liquid-phase microextraction (LPME) of parabens in water samples, pharmaceuticals and personal care products. Brij-35 is a cost-effective and non-toxic non-ionic surfactant, but it has a high cloud point (>100 °C). HFIP, with the features of strong hydrogen-bond donor, high density and powerful hydrophobicity, was used as the cloud point-reducing agent and self-assembling and density-regulating solvent of Brij-35. Upon adding HFIP into the Brij-35 aqueous solution, the cloud point of Brij-35 was decreased to below room temperature, and the SUPRAS was formed in the bottom over a wide range of HFIP and Brij-35 concentrations at room temperature. The SUPRAS was composed of Brij-35, HFIP and water, having a density larger than water, and it showed a large spherical structure of positive micellar aggregates (2-8 μm). The HFIP/ Brij-35 SUPRAS-based LPME procedure was non-thermodependent and could be performed at room temperature with centrifugation using normal centrifuge tubes, being very simple. In the extraction of six parabens, the HFIP/ Brij-35 SUPRAS-based LPME method showed short extraction time (3.3 min), low solvent consumption (0.3 mL), and large enrichment factor (26-193). The method of HFIP/ Brij-35 SUPRAS-based LPME with HPLC-DAD gave good linearity for the quantification of parabens with correlation coefficients larger than 0.9990. The limits of detection based on a signal-to-noise ratio of 3 were from 0.042 to 0.167 μg L -1 . The recoveries for the spiked real samples were in the range of 90.2-112.4% with relative standard deviation less than 8.9%. Except for tap water, one or several paraben (s) were detected in all the other real samples., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Analyzing of tumor markers has become an important means for cancer diagnosis and prevention. In this study, a novel solid phase extraction based on porous magnetic cyclodextrin polymer (MA-CD) was developed and used for detection of trace small molecule gastric tumor markers in urine samples. The adsorption properties of the magnetic cyclodextrin polymer were tested. Through experiments of the solid phase extraction (SPE) at the different condition, the optimal condition was selected to test the two tumor markers by High-performance-liquid chromatography -Diode array detector (HPLC-DAD). The analytical performance of the method showed good accuracy (88.82%-104.34%) and precision (< 3.55%), appropriated detection limits (1.016 and 5.714 μg L -1 ) and linear ranges (0.6-24.0 μg L -1 ) with convenient determination coefficients (> 0.9994). The results demonstrated that the developed approach is efficient, low-cost for gastric tumor markers detection., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Preparation of stir bar extraction (SBSE) device with high physical and chemical stability is important and challenging by date. A novel poly (ether ether ketone) (PEEK) tube with excellent mechanical property and chemical stability was firstly used as jacket of metal bar for preparation of stir bar. By employing covalent modification method, the inherent chemical resistant problem of PEEK which restricts the modification of sorbents was well solved. After functionalization, plenty of benzoic acid groups were formed onto the PEEK jacket. Metal organic frameworks of aluminium-based Materials of Institute Lavoisier-68 (MIL-68) was in situ immobilized onto the PEEK surface (MIL-68@PEEK) by the bonding with benzoic acid groups. Afterwards, a facile dumbbell-shaped structure was designed for reducing the friction between sorbents and bottom of container. Due to superior property of the PEEK jacket and the covalent modification method, the MIL-68 modified PEEK jacket SBSE device showed good robustness. After coupling with HPLC-MS/MS, the MIL-68@PEEK-based SBSE device was used to analyse of three parabens including methyl paraben, ethyl paraben and propyl paraben. The method had low limit detection up to 1 pg mL -1 with good linearity (R 2  ≥ 0.9978) and good reproducibility (relative standard deviation ≤ 9.74%). The method has been applied to the detection of parabens in cosmetics and rabbit plasma after painted with cosmetics with recoveries between 73.25% and 104.23%., (Copyright © 2018 Elsevier B.V. All rights reserved.)

This study describes the use of a magnetic multi-walled carbon nanotube composite for the preconcentration of nine parabens (methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, phenyl and benzylparaben) from water and urine samples after in situ acetylation. The enriched extracts were obtained by dispersive magnetic solid phase extraction (DMSPE) and analysed by gas chromatography with mass spectrometry (GC-MS). Several parameters affecting the adsorption (extraction time, magnetic material mass and ionic strength) and desorption (desorption solvent nature and volume, and desorption time) DMSPE steps were investigated. Matrix-matched calibration was recommended for quantification of the samples. Linearities in the 0.5-150 ng mL -1 range were obtained, depending on the compound. Under the optimal experimental conditions, the limits of detection ranged between 0.03 and 2.0 ng mL -1 , depending on the sample matrix and the paraben congener. None of the samples analysed contained the above mentioned parabens. The method was validated with two water samples (harbour and wastewater treatment plant) and two urine samples spiked at two concentration levels. Recoveries in the 81-119% range were obtained., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Simultaneous derivatization and air-assisted liquid-liquid microextraction using an organic that is solvent lighter than water has been developed for the extraction of some parabens in different samples with the aid of a newly designed device for collecting the extractant. For this purpose, the sample solution is transferred into a glass test tube and a few microliters of acetic anhydride (as a derivatization agent) and p-xylene (as an extraction solvent) are added to the solution. After performing the procedure, the homemade device consists of an inverse funnel with a capillary tube placed into the tube. In this step, the collected extraction solvent and a part of the aqueous solution are transferred into the device and the organic phase indwells in the capillary tube of the device. Under the optimal conditions, limits of detection and quantification for the analytes were obtained in the ranges of 0.90-2.7 and 3.0-6.1 ng/mL, respectively. The enrichment and enhancement factors were in the ranges of 370-430 and 489-660, respectively. The method precision, expressed as the relative standard deviation, was within the range of 4-6% (n = 6) and 4-9% (n = 4) for intra- and interday precisions, respectively. The proposed method was successfully used for the determination of methyl-, ethyl-, and propyl parabens in cosmetic, hygiene and food samples, and personal care products., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

An analytical method is presented for the determination of paraben preservatives in semisolid cream samples by matrix solid-phase dispersion combined with supramolecular solvent-based microextraction. Due to the oily and sticky nature of the sample matrix, parabens were first extracted from the samples by matrix solid-phase dispersion using silica as sorbent material with a clean-up performed with tetrahydrofuran in the elution step. The eluate (500 μL), 1-decanol (120 μL), and water (4.4 mL) were then mixed in a polyethylene pipette to form supramolecular solvent. Finally, the analytes in the supramolecular solvent were separated and determined by liquid chromatography with ultraviolet detection. Under optimal extraction conditions, the extraction recoveries of the studied compounds were obtained in the range of 63-83%. The limits of detection for the analytes were between 0.03 and 0.04 μg/g. The precision of the method varied between 4.0-6.7 (intraday) and 6.2-7.9% (interday). Finally, the optimized procedure was applied to the determination of the target preservatives in a variety of cream samples (diaper rash, skin allergy, face and hand moisturizing) with satisfactory recoveries (86-102%)., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Personal care products (PCPs) are ubiquitous in aquatic environments owing to the continuous discharge of domestic wastewater from highly urbanized regions. These PCPs can be adsorbed by fish and thereafter usually enter the bile of the fish through biliary excretion. In this study, a sensitive method based on a combination of hybrid solvent precipitation and dispersive solid phase extraction (d-SPE) purification was developed to simultaneously extract and detect 24 PCPs, namely, 16 biocides, 4 synthetic musks, and 4 benzotriazoles, from fish bile. Hybrid precipitation on solid phase extraction (SPE) tubes was applied to remove phospholipids and proteins, and a d-SPE procedure was used for further purification. The extraction solvents for the hybrid precipitation/SPE tubes and d-SPE materials were optimized. The method performance for bile samples both with and without enzyme hydrolysis using β-glucuronidase/aryl-sulfatase were validated. The 24 PCPs in fish bile were spiked with standard concentrations of 10 ng/mL, 20 ng/mL, 100 ng/mL, and 200 ng/mL to evaluate recoveries, which ranged from 70 to 120% for 16, 16, 22, and 21 analytes with hydrolysis, respectively, and 70-120% for 14, 15, 23, and 23 analytes without hydrolysis, respectively. The quantification limits for target PCPs were in the range 0.26-7.38 ng/mL [excluding musk xylene (MX) and musk ketone (MK)] and 0.20-9.48 ng/mL (excluding MX and MK) for bile samples with and without enzyme hydrolysis, respectively. After enzyme hydrolysis, 12 PCPs were detected in bile from fish collected from the Yangtze River, with a maximum detected concentration of 460 ng/mL, for triclosan (TCS). The hydrolysis reaction indicated that high percentages of glucuronide and sulfate metabolites for some PCPs, i.e. four parabens and TCS, existed in the bile., (Copyright © 2018 Elsevier B.V. All rights reserved.)

In this work, magnetic carbon material derived from pomelo peels (MCMPs) was conveniently fabricated utilizing one-pot synthesis method and employed as adsorbent of magnetic solid-phase extraction (MSPE). Several characterized measures including infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and vibrating sample magnetometer were used to investigate the morphology, spectroscopic and magnetic properties of prepared adsorbent. Apolar parabens and polar fluoroquinolones (FQs) were used to investigate the extraction performance of MCMPs. Under the optimized extraction conditions, the MCMPs displayed satisfactory extraction performance for target analytes. At the same time, the MCMPs/MSPE was combined with HPLC-DAD for the sensitive determination of parabens and FQs in real-life water samples. Results showed that the limits of detection (S/N = 3) for parabens and FQs were in the ranges of 0.011-0.053 μg/L and 0.012-0.46 μg/L, respectively. The spiked recoveries were in the range of 76.6-116% for parabens and 80.2-114% for FQs with good repeatability (relative standard deviations less than 10%). In comparison to reported methods, the developed MCMPs/MSPE-HPLC-DAD showed some merits including low-cost, simplicity, satisfactory sensitivity and green non-pollution., (Copyright © 2018 Elsevier B.V. All rights reserved.)

In order to exploit the rich reservoir of marine cold-adapted bacteria as a source of bioactive metabolites, ethyl acetate crude extracts of thirteen polar marine bacteria were tested for their antiproliferative activity on A549 lung epithelial cancer cells. The crude extract from Pseudoalteromonas haloplanktis TAC125 was the most active in inhibiting cell proliferation. Extensive bioassay-guided purification and mass spectrometric characterization allowed the identification of 4-hydroxybenzoic acid (4-HBA) as the molecule responsible for this bioactivity. We further demonstrate that 4-HBA inhibits A549 cancer cell proliferation with an IC 50 value ≤ 1 μg ml -1 , and that the effect is specific, since the other two HBA isomers (i.e. 2-HBA and 3-HBA) were unable to inhibit cell proliferation. The effect of 4-HBA is also selective since treatment of normal lung epithelial cells (WI-38) with 4-HBA did not affect cell viability. Finally, we show that 4-HBA is able to activate, at the gene and protein levels, a specific cell death signaling pathway named pyroptosis. Accordingly, the treatment of A549 cells with 4-HBA induces the transcription of (amongst others) caspase-1, IL1β, and IL18 encoding genes. Studies needed for the elucidation of mode of action of 4-HBA will be instrumental in depicting novel details of pyroptosis.

A new polymeric ionic liquid-modified magnetic adsorbent (PIL-MA) was successfully fabricated and used to extract apolar and polar pollutants with magnetic solid-phase extraction (MSPE). The PIL-MA was prepared by simple free radical copolymerization of 1-vinylbenzyl-3-methylimidazolium hexafluorophosphate, divinylbenzene and silica-coated magnetite. Several characterized techniques including infrared spectroscopy, elemental analysis, scanning electron microscopy, transmission electron microscopy and magnetic measurement were used to characterize the PIL-MA. Parabens and aromatic amines were selected as test analytes to investigate the extraction performance of PIL-MA for apolar and strongly polar analytes, respectively. The extraction parameters including the amount of PIL-MA, adsorption time, desorption solvent and time, pH value and ionic strength were optimized thoroughly. At the same time, convenient and sensitive analytical methods for parabens and aromatic amines in real samples were developed by the combination of PIL-MA-MSPE and HPLC-DAD. Results well demonstrate that there are abundant active groups in the PIL-MA and multiply interactions including π-π, hydrophobic, hydrogen-bonding and dipole-dipole are involved in the extraction., (Copyright © 2017 Elsevier B.V. All rights reserved.)

An effective and solvent-less method for the rapid determination of four commonly detected parabens (methyl-, ethyl-, propyl- and butyl-) in human urine samples is described. This method employed ultrasound-assisted emulsification microextraction (USAEME) before identification and quantitation of the parabens via on-line acetylation gas chromatography-mass spectrometry (GC-MS). Urine samples were enzymatically de-conjugated with β-glucuronidase and then extracted by an optimal USAEME procedure for the measurement of total concentrations of target analytes. The optimal USAEME parameters for one mL of urine sample (containing 0.1-g of sodium chloride), according to the Box-Behnken design method, are thus described: extractant of 200-μL of ethyl acetate, and ultrasonication for 1.0min and centrifugation at 7000rpm (3min). The supernatant was collected and evaporated until dry. Then the residue was re-dissolved in methanol (100-μL), and the extract was subjected to on-line acetylation GC-MS analysis. The limits of quantitation (LOQs) were less than 0.06ng/mL. Precisions for both intra- and inter-day analysis were calculated, and were less than 8%. Mean extraction recovery (known as trueness) was between 83 and 101% on three concentration levels. In human urine, the total concentrations of the four selected parabens, according to preliminary results, range from 0.3 to 124.5ng/mL for male, and from 27.2 to 246.3ng/mL for female. Female urine samples showed higher concentrations for the target parabens, which may indicate higher exposure due to lifestyle. This method permits accurate and high-throughput analysis of parabens for epidemiological studies., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In the present work, magnetically assisted matrix solid phase dispersion (MA-MSPD) was used as an efficient solid phase extraction method. MA-MSPD followed by a dispersive liquid-liquid microextraction (DLLME) was applied for determination of parabens in breast milks. The analysis were performed using LC-UV and LC-MS/MS. Poly(indole-thiophene) coated magnetic graphene oxide (MGO@PIT) was synthesized, characterized and used as the sorbent. Na 2 SO 4 was used as the drying salt as well as matrix dispersing agent. Exact amounts of MGO@PIT and Na 2 SO 4 were added into 200μL volume of the milk and the mixture was gently blended to obtain a dry powder. The blend was dispersed into ultrapure water and stirred. Because of dissolving of the matrix dispersant in water, only the magnetic sorbent is remained into water which can be easily separated by a magnet. Next, the sorbent was eluted with a suitable solvent to desorb the analyte and the eluent was used as the disperser solvent for the subsequent DLLME. In this approach, the target analytes were directly adsorbed on the surface of the magnetic sorbent without any sample pretreatment. Compared with conventional MSPD, MA-MSPD increases the simplicity of the extraction procedure, decreases the extraction time and eliminates the column packing as well as its related drawbacks. The optimum extraction parameters were obtained as 50mg of MGO@PIT, 550mg of Na 2 SO 4 in 200μL of the milk sample, 1.0mL of methanol as the eluent solvent under fierce vortex for 2.0min and 100μL of 1-octanol as the extraction solvent. Under the optimal conditions, the extraction recoveries greater than 83% were obtained, and LOD and LOQ values were found 25ngmL -1 (about 0.5ngmL -1 by LC-MS/MS) and 50ngmL -1 using LC-UV, respectively. The calibration curves were in the range of 50-4000ngmL -1 with the determination coefficients (R 2 ) higher than 0.998. Relative standard deviations (RSD%) for intra- and inter-day precisions were less than 7.5% and 11.3%, respectively. The results confirmed that the proposed method is a rapid, feasible and convenient technique which makes it suitable for the analysis of parabens from breast milk samples., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The preparative separation of intermediately-eluting components in liquid-liquid chromatography is commonly performed with isocratic batch injections, a technique which often leads to low yield and/or purity as a result of peak overlap. Two-column trapping multiple dual mode centrifugal partition chromatography, an alternative discontinuous method for the separation of a mixture into three product fractions (early-, intermediately-, and late-eluting components) at full recovery, is presented in this work. A mathematical shortcut method based on equilibrium theory assumptions is derived for the determination of the key operating parameters (i.e., step durations and number of steps). The feasibility of the technique and the accompanying short-cut method is demonstrated by proof-of-concept experiments for the separation of two paraben model mixtures., (Copyright © 2017 Elsevier B.V. All rights reserved.)

A fast double-flow microfluidic based liquid phase microextraction (DF-µLPME) combined with a HPLC-UV procedure using diode array detection has been developed for the determination of the four most widely used parabens: Ethyl 4-hydroxybenzoate (EtP), Propyl 4-hydroxybenzoate (PrP), Butyl 4-hydroxybenzoate (BuP) and IsoButyl 4-hydroxybenzoate (iBuP) in water samples. Parabens have successfully been determined in environmental (lake and river water) samples with excellent clean up, high extraction efficiency and good enrichment factor using double-flow conditions. The microfluidic device consists of two micro-channels, which contain the acceptor and sample solution separated by a flat membrane (support liquid membrane). The sample (0.32mM HCl) and acceptor phase (5.6mM NaOH) are delivered to the µLPME at 10µLmin -1 and 1µLmin -1 flow rate, respectively. The extraction efficiencies are over 84% for all compounds in water samples with enrichment factors within the range of 9-11 and recoveries over 80%. The procedure provides very low detection limits between 1.6 and 3.5µgL -1 . The extraction time and the volume required for the extraction are 5min and 50µL, respectively; which are greatly lower compared to any previous extraction procedure for parabens analysis. In addition, this miniaturized DF- µLPME procedure significantly reduces costs compared to not only the existing methods for paraben detection, but also to the existing analytical techniques for sample preparation., (Copyright © 2017 Elsevier B.V. All rights reserved.)

This study aims to identify special metabolites in polar extracts from Urochloa humidicola (synonym Brachiaria humidicola) that have allelopathic effects and induce secondary photosensitization in ruminants. The compounds were isolated and identified via chromatographic and spectroscopic techniques. The compounds 4-hydroxy-3-methoxy-benzoic acid, trans-4-hydroxycinnamic acid, and p-hydroxy-benzoic acid; the flavonols isorhamnetin-3-O-β-d-glucopyranoside and methyl quercetin-3-O-β-d-glucuronate; and kaempferitrin, quercetin-3-O-α-l-rhamnopyranoside, and tricin were identified in the extract from the leaves of Urochloa humidicola. Two furostanic saponins, namely, dioscin and 3-O-α-l-rhamnopyranosyl-(1-4)-[α-l-rhamnopyranosyl-(1-2)]-β-d-glucopyranosyl-penogenin, as well as catechin-7-O-β-d-glucopyranoside were identified in the methanolic extract obtained from the roots of this plant. This species features a range of metabolites that may be toxic for animals if used in food and may interfere with the growth medium, thereby inhibiting the development of other species.

This paper describes the synthesis, characterization and use of graphene supported on aminopropyl silica through covalent bonds (Si-G) as a sorbent for microextraction by packed sorbent (MEPS). Five parabens (methyl, ethyl, propyl, butyl and benzyl) present in water matrices were used as model compounds for this evaluation. The Si-G phase was compared to other sorbents used in MEPS (C18 and Strata™-X) and also with graphene supported on primary-secondary amine (PSA) silica, where Si-G showed better results. After this, the MEPS experimental parameters were optimized using the Si-G sorbent. The following variables were optimized through univariate experiments: pH (4,7 and 10), desorption solvent (ACN:MeOH (50:50), ACN:H 2 O (40:60), MeOH and ACN) and ionic strength (0, 10 and 20% of NaCl). A factorial design 2 6-2 was then employed to evaluate other variables, such as the sample volume, desorption volume, sampling cycles, wash cycles and desorption cycles, as well as the influence of NaCl% on the extraction performance. The optimized method achieved a linear range of 0.2-20μg/L for most parabens; weighted calibration models were employed during the linearity evaluation to reduce the absolute sum of the residue values and improve R 2 , which ranged from 0.9753 to 0.9849. The method's accuracy was 82.3-119.2%; precision, evaluated as the coefficient of variance for intraday and interday analysis, ranged from 1.5 to 19.2%. After evaluation of the figures of merit, the method was applied to the determination of parabens in water samples., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Methylparaben (MePB) is an organic compound employed mainly in the manufacture of different personal care products. However, it has been recently listed as a potential endocrine disrupter chemical. Therefore, the main objective of this work was to evaluate the degradation of MePB in aqueous solutions using heterogeneous photocatalysis with TiO 2 and hydrogen peroxide. In this way, effects of pH and the initial concentrations of catalyst, H 2 O 2 , and pollutant on treatment were analyzed. A face centered, central composite design was used for determination of the influence of each parameter in the process and the conditions under which the pollutant suffers the highest rates of degradation were selected. In general, results indicate that combination TiO 2 /H 2 O 2 /light irradiation leads to ∼90 % of substrate removal after 30 min of reaction and that hydroxyl free radicals are the main specie responsible for organic matter elimination. Finally, in terms of mineralization and biodegradability, experimental results indicated that part of the organic matter was transformed into CO 2 and water and the photo-treatment promoted an increase in samples biodegradability.

Polar and hydrophilic properties of hydroxybenzoic acids usually made them coelute with interferences in high performance liquid chromatography (HPLC) analysis. Then selective analysis of them was necessary. Herein, hollow porous ionic liquids composite polymers (PILs) based solid phase extraction (SPE) was firstly fabricated and coupled online with HPLC for selective analysis of hydroxybenzoic acids from complex matrices. Hollow porous PILs were firstly synthesized using Mobil Composition of Matter No. 48 (MCM-48) spheres as sacrificial support, 1-vinyl-3-methylimidazolium chloride (VMIM + Cl - ) as monomer, and ethylene glycol dimethacrylate (EGDMA) as cross-linker. Various parameters affecting synthesis, adsorption and desorption behaviors were investigated and optimized. Steady-state adsorption studies showed the resulting hollow porous PILs exhibited high adsorption capacity, fast adsorption kinetics, and excellent specific adsorption. Subsequently, the application of online SPE system was studied by selective analysis of protocatechuic acid (PCA), 4-hydroxybenzoic acid (4-HBA), and vanillic acid (VA) from Pollen Typha angustifolia. The obtained limit of detection (LOD) varied from 0.002 to 0.01μg/mL, the linear range (0.05-5.0μg/mL) was wide with correlation coefficient (R) from 0.9982 to 0.9994, and the average recoveries at three spiking levels ranged from 82.7 to 102.4%, with column-to-column relative standard deviation (RSD) below 8.1%. The proposed online method showed good accuracy, precision, specificity and convenience, which opened up a universal and efficient route for selective analysis of hydroxybenzoic acids from complex samples., (Copyright © 2017 Elsevier B.V. All rights reserved.)

An ultrasound-assisted surfactant-enhanced emulsification micro-extraction (UASEME) procedure has been developed for pre-concentration of benzoic acid (BA) and paraben preservatives, including methylparaben, ethylparaben, propylparaben and butylparaben, prior to high-performance liquid chromatography-ultraviolet (HPLC-UV) analysis. Separations were performed on a Lichrospher RP-18 endcapped 5 µm, using an isocratic mobile phase of 40% acetonitile, at a flow rate of 1 mL min -1 The selected UASEME conditions comprised the use of 10 mL sample extract, 125 µL 1-octanol as extraction solvent and 0.05 mmol L -1 Tween 20 as emulsifier, 0.5% sodium chloride, ultrasonication time of 6 min and centrifugation time of 10 min. Method performance demonstrated wide linear range between 0.5 and 7,000 µg L -1 (R 2  > 0.9903) and limits of detection between 0.03 and 10 µg L -1 , which providing the enrichment factors of 15-184. The method precision (relative standard deviation) was <7%. The developed UASEME coupled with HPLC-UV has been successfully applied to determine four paraben preservatives in various sample matrices such as water, beverages and personal care products. The recoveries in the range of 70-138.1% were obtained. However, BA could not be determined in real sample extracts., (© The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

The research into the separation of drug enantiomers is closely related to the safety and efficiency of the drugs. The aim of this study was to develop a simple and validated HPLC method to analyze cetirizine enantiomers. In the case of liquid dosage forms, besides the active substance in large amounts there are usually also inactive ingredients such as methyl- and propylparaben. Unfortunately, these compounds can interfere with the analyte, inter alia during chiral separation of the analyte enantiomers. The proposed innovative two-step liquid-liquid extraction procedure allowed for the determination of cetirizine enantiomers (along with M and P parabens) also in liquid dosage forms. The main focus of this study was the chromatographic activity of cetirizine dihydrochloride on the proteinate-based chiral stationary phase. The chromatographic separation of cetirizine enantiomers was performed on an immobilized human serum albumin (HSA) column for the first time. Measurements were performed at a wavelength of 227 nm. Under optimal conditions, baseline separation of two enantiomers was obtained with 1.43 enantioseparation factor (α) and 1.82 resolution ( R s ). Finally, the proposed method was successfully applied to the selected pharmaceutical formulations.

An effective method for determining four commonly detected paraben preservatives (methyl, ethyl, propyl and butyl paraben) in marketed seafood is presented. This method employs matrix solid-phase dispersion (MSPD) before identification and quantification of the paraben preservatives via on-line acetylation gas chromatography-mass spectrometry (GC-MS). Parameters affecting the extraction efficiency of MSPD were optimized through a Box-Behnken design method. Under optimal condition, 0.5-g of freeze-dried seafood was mixed with 0.5-g of anhydrous sodium sulfate, and dispersed with 1.0-g of Florisil using vortex. After that, the blend was transferred to a glass column containing 1.5-g of silica gel+C18 (w/w, 9:1), which acted as clean-up co-sorbents. Then, target analytes were eluted with 12mL of acetonitrile. The extract was then derivatized on-line in the GC injection-port through reaction with acetic anhydride, and the identity and quantity of the target analytes were determined by the GC-MS system. The limits of quantitation (LOQs) were 0.2 to 1.0ng/g (dry weight). Preliminary results showed that the total concentrations of four selected parabens ranged from 16.7 to 44.7ng/g (dry weight)., (Copyright © 2016 Elsevier B.V. All rights reserved.)

In this work, phenyl-functionalized magnetic graphene/mesoporous silica composites (MG-mSiO2-Ph) were prepared and applied as restricted access matrix solid phase extraction (RAM-SPE) adsorbents to determine the parabens in commercially available retail cosmetics. MG-mSiO2-Ph composites were synthesized by a surfactant-mediated co-condensation reaction in which mesoporous silica with phenyl-functionalized pore-walls was coated on a magnetic graphene sheet. The obtained nano-composites were proven to be of sufficient quality for an ideal RAM-SPE adsorbent with a large specific surface area of 369m(2)g(-1), uniform mesopores of 2.8nm, and special phenyl-functionalized pore-walls. Parabens, such as methyl paraben, ethyl paraben and propyl paraben, were extracted from water-based skin toners using one step of the RAM-SPE and were then analysed by a HPLC-DAD system. The SPE conditions were optimized by studying the parameters, such as the adsorbent amount, elution solvent type, adsorption time and desorption time, that influence the extraction efficiency. For each analyte, there were good linearities of approximately 0.10-120μgmL(-1) with determination coefficients (R(2))>0.995. The sensitivity was as low as 0.01-0.025μgmL(-1) for the LOD, and the percent recoveries were 98.37-105.84%. The intra-day and inter-day RSDs were 1.44-6.11% (n=6) and 3.12-11.70% (n=6), respectively. The results indicated that this method with novel RAM-SPE adsorbents is sensitive and convenient. The results also offered an attractive alternative for the extraction and determination of paraben preservatives in a complex matrix, such as cosmetics., (Copyright © 2016 Elsevier B.V. All rights reserved.)

It has been proposed to remove all potential inhibitors and sulfuric acid in biomass hydrolysates generated from dilute-acid pretreatment of biomass, based on three steps of sugar purification process. This study focused on its first step in which furan and phenolic compounds were selectively removed from the simulated hydrolysates using activated charcoal. Batch adsorption experiments demonstrated that the affinity of activated charcoal for each component was highest in the order of vanillic acid, 4-hydroxybenzoic acid, furfural, acetic acid, sulfuric acid, and xylose. The affinity of activated charcoal for furan and phenolic compounds proved to be significantly higher than that of the other three components. Four separation strategies were conducted with a combination of batch adsorption and continuous fixed-bed column adsorption methods. It was observed that xylose loss was negligible with near complete removal of furan and phenolic compounds, when at least one fixed-bed column adsorption was implemented in the strategy., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

A new molecularly imprinted polymer modified with restricted access material (a hydrophilic external layer), (MIP-RAM) was synthesized via polymerization in situ in an open fused silica capillary. This stationary phase was used as sorbent for in-tube solid phase microextraction (in-tube SPME) to determine parabens in breast milk samples by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Scanning electron micrographs (SEM) illustrate MIP surface modification after glycerol dimethacrylate (hydrophilic monomer) incorporation. The interaction between parabens and MIP-RAM was investigated by Fourier-transform infrared (FTIR) spectroscopy. The Scatchard plot for MIP-RAM presented two linear parts with different slopes, illustrating binding sites with high- and low-affinity. Endogenous compounds exclusion from the MIP-RAM capillary was demonstrated by in-tube SPME/LC-UV assays carried out with blank milk samples. The in-tube SPME/UHPLC-MS/MS method presented linear range from 10 ng mL(-1) (LLOQ) to 400 ng mL(-1) with coefficients of determination higher than 0.99, inter-assay precision with coefficient of variation (CV) values ranging from 2 to 15%, and inter-assay accuracy with relative standard deviation (RSD) values ranging from -1% to 19%. Analytical validation parameters attested that in-tube SPME/UHPLC-MS/MS is an appropriate method to determine parabens in human milk samples to assess human exposure to these compounds. Analysis of breast milk samples from lactating women demonstrated that the proposed method is effective., (Copyright © 2016 Elsevier B.V. All rights reserved.)

A method for the extraction and determination of seven parabens, esters of 4-hydroxybenzoic acid, widely used as preservatives in personal care products, pharmaceuticals, etc., and two chlorinated derivatives (mono- and di-chloro methyl paraben) from mollusk samples was developed by combining matrix solid-phase dispersion (MSPD) and liquid chromatography-tandem mass spectrometry. MSPD parameters, such as solvent, solid support and clean-up sorbent, were optimized. Besides, since blank problems were observed for some parabens, these were investigated and blanks were tackled by precleaning all sorbents prior to use. Under final conditions, 0.5g of freeze-dried mollusk were dispersed with 1.2g of silica and packed into a cartridge containing 3g of C18, as on-line clean-up sorbent. This cartridge was eluted with 10mL of acetonitrile, evaporated and reconstituted in methanol for analysis. In the validation stage, successful linearity (R(2)>0.999), recoveries (between 71 and 117% for most analytes), precision (RSD lower than 21%) and limits of detection and quantification (LOD and LOQ, lower than 0.4 and 1.4ngg(-1) dry weight respectively) levels were achieved. Finally, the new methodology was applied to mussel, clam and cockle samples. Methyl paraben was above the LOQ in five of the six samples (not found in one clam sample) at concentrations up to 7ngg(-1) dry weight. Ethyl paraben was found above the LOQ in mussel and cockle samples at a concentration level around 0.3ngg(-1). n-Propyl paraben was only above the LOQ in one mussel sample., (Copyright © 2016 Elsevier B.V. All rights reserved.)

A silica-based surface magnetic molecularly imprinted polymer for the selective recognition of parabens was prepared using a facile and general method that combined atom-transfer radical polymerization with surface imprinting technique. The prepared magnetic molecularly imprinted polymer was characterized by transmission electron microscopy, Fourier transform infrared spectrometry and physical property measurement. The isothermal adsorption experiment and kinetics adsorption experiment investigated the adsorption property of magnetic molecularly imprinted polymer to template molecule. The four parabens including methylparaben, ethylparaben, propylparaben, and butylparaben were used to assess the rebinding selectivity. An extraction method, which used magnetic molecularly imprinted polymer as adsorbents coupled with high-performance liquid chromatography for the determination of the four parabens in fruit juice samples was developed. Under the optimal conditions, the limits of detections of the four parabens were 0.028, 0.026, 0.021, and 0.026 mg/L, respectively. The precision expressed as relative standard deviation ranging from 2.6 to 8.9% was obtained. In all three fortified levels, recoveries of parabens were in the range of 72.5-89.4%. The proposed method has been applied to different fruit juice samples including orange juice, grape juice, apple juice and peach juice, and satisfactory results were obtained., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Some plants secrete toxic nectar to appeal to most effective pollinators and deter non-pollinators or nectar thieves; however available information about ecological function of toxic nectar remains scarce. Elsholtzia rugulosa stands out as a plant with toxic nectar recorded in SW China. We focused on the functional significance of the phenolic compound that imparts toxic to the nectar of E. rugulosa. The effects of phenolic nectar were studied in three visitors of the flowers of the winter-blooming E. rugulosa Hemsl. (Lamiaceae) in SW China. The pollinating species Apis cerana Fabricius (Apidae; Asian honey bee) and two occasional visitors, Vespa velutina Lepeletier (Vespidae; yellow-legged Asian hornet) and Bombus eximius Smith (Apidae; a bumble bee) were tested for their preferences for low and high concentrations of 4-hydroxybenzoic acid in hexose and sucrose solutions. The pollinator is important for the plant, which is dependent on pollinator visits to attain a higher seed production and it is most likely that the combination of phenolic toxic nectar and the adaptation to phenolic nectar by A. cerana delivers an evolutionary advantage to both actors. The low and high concentrations of the phenolic acid were nearly totally refused by both occasional visitors V. velutina and B. eximius and were preferred by the pollinator A. cerana. E. rugulosa gains by having a much higher seed production and the pollinating honey bee by having an exclusive and reliable food source during the winter season at high altitudes in SW China. We found that the function of the toxic phenolic compound has dual roles by appealing to legitimate pollinators and deterring non-pollinators of E. rugulosa.

An accurate and sensitive method for the determination of selected EDCs in soil and compost from wastewater treatment plants is developed and validated. Five parabens, six benzophenone-UV filters and the antibacterials triclosan and triclocarban were selected as target analytes. The parameters for ultrasound-assisted extraction were thoroughly optimized. After extraction, the analytes were detected and quantified using ultra-high performance liquid chromatography tandem mass spectrometry. Ethylparaben (ring-(13)C6 labelled) and deuterated benzophenone (BP-d10) were used as internal standards. The method was validated using matrix-matched calibration and recovery assays with spiked samples. The limits of detection ranged from 0.03 to 0.40 ng g(-1) and the limits of quantification from 0.1 to 1.0 ng g(-1), while precision in terms of relative standard deviation was between 9% and 21%. Recovery rates ranged from 83% to 107%. The validated method was applied for the study of the behavior of the selected compounds in agricultural soils treated and un-treated with compost from WWTP. A lixiviation study was developed in both agricultural soil and treated soil and first order kinetic models of their disappearance at different depths are proposed. The application of organic composts in the soil leads to an increase of the disappearance rate of the studied compounds. The lixiviation study also shows the risk of pollution of groundwater aquifers after disposal or waste of these EDCs in agricultural soils is not high., (Copyright © 2015 Elsevier B.V. All rights reserved.)

A phytochemical study of Ficus thonningii has led to the isolation of two previously unreported compounds, thonningiiflavanonol A and thonningiiflavanonol B together with 16 known compounds: shuterin, naringenin, syringic acid, p-hydroxybenzoic acid, genistein, 5,7,3',4',5'-pentahydroxyflavanone, luteolin, methylparaben, aromadendrin, garbanzol, dihydroquercetin, 5,7,3'-trihydroxyflavanone, β-sitosterol, sitosterolglucoside, lupeol acetate, and taraxerol. Their structures were elucidated on the basis of spectroscopic data. The new compounds and extracts displayed potent antioxidant activity.

For the first time, an efficient and sensitive analytical method based on liquid chromatography-quadrupole linear ion trap-tandem mass spectrometry (LC-QqLIT-MS/MS) was developed for the simultaneous determination of four paraben-type preservatives and three benzophenone-type ultraviolet light filters in both plant (Sargassum fusiforme, porphyra, kelp) and animal (hairtail, yellow croaker, shrimp) seafood. The samples were extracted in methanol by pressurized liquid extraction (PLE), and the extracts were then cleaned up by mixed-mode cationic exchange (MCX) solid-phase extraction cartridges. Both isotope-labeled internal standards and matrix-matched calibration standards were used to alleviate and correct for the matrix effects, and the limits of quantification (LOQs) were 10.0μg kg(-1) for all target compounds. The average recoveries were in the range of 80.6-107.8% at three spiked concentration levels (10, 50 and 100μgkg(-1)) with relative standard deviations (RSDs) below 8.5%. The results suggest that very limited contamination of these seven emerging contaminants, mainly associated with PCPs, occurred in these common seafoods., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

The wild mushroom Leucopaxillus candidus (Bres.) Singer was studied for the first time to obtain information about its chemical composition, nutritional value and bioactivity. Free sugars, fatty acids, tocopherols, organic and phenolic acids were analysed by chromatographic techniques coupled to different detectors. L. candidus methanolic extract was tested regarding antioxidant potential (reducing power, radical scavenging activity and lipid peroxidation inhibition). L. candidus was shown to be an interesting species in terms of nutritional value, with high content in proteins and carbohydrates, but low fat levels, with the prevalence of polyunsaturated fatty acids. Mannitol was the most abundant free sugar and β-tocopherol was the main tocopherol isoform. Other compounds detected were oxalic and fumaric acids, p-hydroxybenzoic and cinnamic acids. The methanolic extract revealed antioxidant activity and did not show hepatoxicity in porcine liver primary cells. The present study provides new information about L. candidus.

Gynura bicolor (Compositae) is a popular vegetable in Asia and believed to confer a wide range of benefits including anti-cancer. Our previous findings showed that the ethyl acetate extract of G. bicolor possessed cytotoxicity and induced apoptotic and necrotic cell death in human colon carcinoma cells (HCT 116). A combination of column chromatography had been used to purify chemical constituents from the ethyl acetate and water extract of G. bicolor leaves. Eight chemical constituents 5-p-trans-coumaroylquinic acid (I), 4-hydroxybenzoic acid (II), rutin (III), kampferol-3-O-rutinoside (IV), 3,5-dicaffeoylquinic acid (V), kampferol-3-O-glucoside (VI), guanosine (VII) and chlorogenic acid (VIII) were isolated from G. bicolor grown in Malaysia. To our best knowledge, all chemical constituents were isolated for the first time from G. bicolor leaves except rutin (III). 3,5-dicaffeoylquinic acid (V), guanosine (VII) and chlorogenic acid (VIII) demonstrated selective cytotoxicity (selective index>3) against HCT 116 cancer cells compared to CCD-18Co human normal colon cells.

The effects of extracts from the mycelium of Lecanicilium lecaniiNo.169, Beauveria fellina No.7 and Beauveria bassianaNo.15 on the activity of 15-lpoxygenase (15-LO) recovered from rat reticulocytes was investigated. The activity of 15-LO was determined by oxidation of linolic acid. The extract from the mycelium of the fungal complex was shown to inhibit 15-LO (IC50 of 12 mcg/ml). The inhibitory effect of the combined extract on 15-LO was due to the substances recovered from Lecanicilium lecanii No.169. The extract fractions responsible for the activity were determined and the compounds containing the fractions were identified. They proved to be 10 - 4-hydroxybenzoic acid and 4-hydroxybenzyl alcohol and genistein, a flavonoid from fraction 11. The possible role of the inhibitory effect of the compounds on 15-LO in the antiatherosclerotic activity of the fungal extract is discussed.