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1.
Article in English | MEDLINE | ID: mdl-34666891

ABSTRACT

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.


Subject(s)
Cosmetics/chemistry , Liquid Phase Microextraction/methods , Parabens/analysis , Parabens/isolation & purification , Chromatography, High Pressure Liquid , Green Chemistry Technology , Limit of Detection , Linear Models , Parabens/chemistry , Reproducibility of Results , Solvents/chemistry
2.
Molecules ; 26(15)2021 Jul 30.
Article in English | MEDLINE | ID: mdl-34361795

ABSTRACT

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.


Subject(s)
Antioxidants/chemistry , Crops, Agricultural/chemistry , Flavonoids/chemistry , Vicia faba/chemistry , Antioxidants/classification , Antioxidants/isolation & purification , Australia , Catechin/chemistry , Catechin/isolation & purification , Chlorogenic Acid/chemistry , Chlorogenic Acid/isolation & purification , Chromatography, High Pressure Liquid/methods , Coumaric Acids/chemistry , Coumaric Acids/isolation & purification , Crops, Agricultural/growth & development , Crops, Agricultural/metabolism , Flavonoids/classification , Flavonoids/isolation & purification , Gallic Acid/analogs & derivatives , Gallic Acid/chemistry , Gallic Acid/isolation & purification , Humans , Hydroxybenzoates/chemistry , Hydroxybenzoates/isolation & purification , Parabens/chemistry , Parabens/isolation & purification , Rutin/chemistry , Rutin/isolation & purification , Vanillic Acid/chemistry , Vanillic Acid/isolation & purification , Vicia faba/growth & development , Vicia faba/metabolism
3.
Article in English | MEDLINE | ID: mdl-34325307

ABSTRACT

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.


Subject(s)
Chromatography, High Pressure Liquid/methods , Parabens/analysis , Solid Phase Extraction/methods , Tandem Mass Spectrometry/methods , Breast Neoplasms , Carbon/chemistry , Female , Humans , Limit of Detection , Linear Models , Magnets/chemistry , Parabens/chemistry , Parabens/isolation & purification , Reproducibility of Results
4.
J Sep Sci ; 44(2): 549-556, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33191605

ABSTRACT

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.


Subject(s)
Chitosan/chemistry , Microspheres , Molecular Imprinting , Parabens/isolation & purification , Pyrus/chemistry , Solid Phase Extraction , Adsorption , Hydrogen-Ion Concentration , Parabens/chemistry , Particle Size , Solvents/chemistry , Temperature
5.
Biomed Chromatogr ; 35(2): e4974, 2021 Feb.
Article in English | MEDLINE | ID: mdl-32893361

ABSTRACT

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 C18 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.


Subject(s)
Chemical Fractionation/methods , Chromatography, High Pressure Liquid/methods , Parabens/analysis , Humans , Limit of Detection , Linear Models , Parabens/chemistry , Parabens/isolation & purification , Reproducibility of Results , Textiles
6.
J Chromatogr A ; 1625: 461270, 2020 Aug 16.
Article in English | MEDLINE | ID: mdl-32709322

ABSTRACT

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.


Subject(s)
Electric Impedance , Membranes, Artificial , Microfluidics/instrumentation , Models, Theoretical , Parabens/isolation & purification , Adult , Electrolysis , Female , Humans , Limit of Detection , Reproducibility of Results , Rheology , Solutions
7.
Mikrochim Acta ; 187(7): 388, 2020 06 15.
Article in English | MEDLINE | ID: mdl-32542460

ABSTRACT

A novel magnetic organic porous polymer (denoted as Fe3O4@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 Fe3O4@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.


Subject(s)
Biomarkers, Tumor/urine , Cresols/urine , Magnetite Nanoparticles/chemistry , Parabens/analysis , Polymers/chemistry , Stomach Neoplasms/urine , Adsorption , Biomarkers, Tumor/chemistry , Biomarkers, Tumor/isolation & purification , Chromatography, High Pressure Liquid , Cresols/chemistry , Cresols/isolation & purification , Humans , Limit of Detection , Parabens/chemistry , Parabens/isolation & purification , Piperazines/chemistry , Porosity , Solid Phase Extraction/methods
8.
Nat Prod Res ; 34(21): 3061-3065, 2020 Nov.
Article in English | MEDLINE | ID: mdl-31084212

ABSTRACT

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.


Subject(s)
Artemisia/chemistry , Biological Products/chemistry , Artemisia/metabolism , Biological Products/isolation & purification , China , Coumaric Acids , Magnetic Resonance Spectroscopy , Molecular Structure , Parabens/chemistry , Parabens/isolation & purification , Plant Extracts/chemistry , Propionates/chemistry , Propionates/isolation & purification , Secondary Metabolism , Spectrometry, Mass, Electrospray Ionization , Spectrophotometry, Ultraviolet
9.
J Chromatogr A ; 1612: 460655, 2020 Feb 08.
Article in English | MEDLINE | ID: mdl-31679709

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.


Subject(s)
Chromatography, High Pressure Liquid/methods , Hydrophobic and Hydrophilic Interactions , Nortriptyline/analysis , Nortriptyline/isolation & purification , Parabens/analysis , Parabens/isolation & purification , Temperature , Uridine/analysis , Uridine/isolation & purification
10.
J Sep Sci ; 43(4): 766-773, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31746547

ABSTRACT

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%.


Subject(s)
Food Preservatives/isolation & purification , Ionic Liquids/chemistry , Magnetics/methods , Milk/chemistry , Parabens/isolation & purification , Solid Phase Extraction/methods , Adsorption , Animals , Cattle , Food Preservatives/chemistry , Gas Chromatography-Mass Spectrometry , Limit of Detection , Magnetics/instrumentation , Microspheres , Parabens/chemistry , Solid Phase Extraction/instrumentation
11.
J Chromatogr A ; 1608: 460426, 2019 Dec 20.
Article in English | MEDLINE | ID: mdl-31416622

ABSTRACT

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


Subject(s)
Cosmetics/analysis , Parabens/isolation & purification , Phthalic Acids/isolation & purification , Solid Phase Extraction/methods , Solid Phase Microextraction/methods , Water Pollutants, Chemical/isolation & purification , Adsorption , Chromatography, High Pressure Liquid/methods , Ferrosoferric Oxide/chemistry , Metal-Organic Frameworks/chemistry , Nanotubes, Carbon/chemistry , Parabens/analysis , Phthalic Acids/analysis , Solid Phase Extraction/instrumentation , Solid Phase Microextraction/instrumentation , Water Pollutants, Chemical/analysis
12.
Mikrochim Acta ; 186(9): 622, 2019 08 13.
Article in English | MEDLINE | ID: mdl-31410577

ABSTRACT

Magnetic hydroxyapatite nanoparticles (γ-Fe2O3@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-Fe2O3@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-Fe2O3@HAP nanoadsorbent as a new and effective method with high reproducibility and reusability.


Subject(s)
Durapatite/chemistry , Environment , Ferric Compounds/chemistry , Nanoparticles/chemistry , Parabens/isolation & purification , Solid Phase Extraction/methods , Ultrasonic Waves , Adsorption , Humans , Limit of Detection , Parabens/chemistry , Urinalysis
13.
Article in English | MEDLINE | ID: mdl-31299363

ABSTRACT

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.


Subject(s)
Chromatography, High Pressure Liquid/methods , Parabens/analysis , Parabens/isolation & purification , Plasma/chemistry , Solid Phase Extraction/methods , Urine/chemistry , Chromatography, High Pressure Liquid/instrumentation , Humans , Limit of Detection , Parabens/metabolism , Preservatives, Pharmaceutical/analysis , Preservatives, Pharmaceutical/isolation & purification , Preservatives, Pharmaceutical/metabolism
14.
J Chromatogr A ; 1601: 71-78, 2019 Sep 13.
Article in English | MEDLINE | ID: mdl-31133426

ABSTRACT

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%.


Subject(s)
Condiments/analysis , Food Analysis/methods , Parabens/analysis , Parabens/isolation & purification , Resins, Synthetic/chemistry , Adsorption , Gas Chromatography-Mass Spectrometry , Limit of Detection , Porosity
15.
J Chromatogr A ; 1599: 25-34, 2019 Aug 16.
Article in English | MEDLINE | ID: mdl-30987787

ABSTRACT

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.


Subject(s)
Food Analysis/methods , Graphite/chemistry , Milk/chemistry , Nanofibers/chemistry , Nylons/chemistry , Parabens/isolation & purification , Polymers/chemistry , Pyrroles/chemistry , Adsorption , Animals , Chromatography, High Pressure Liquid , Parabens/analysis , Solid Phase Microextraction , Solvents/chemistry , Spectroscopy, Fourier Transform Infrared
16.
J Chromatogr A ; 1591: 33-43, 2019 Apr 26.
Article in English | MEDLINE | ID: mdl-30660441

ABSTRACT

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.


Subject(s)
Liquid Phase Microextraction/methods , Parabens/isolation & purification , Polyethylene Glycols/chemistry , Propanols/chemistry , Solvents/chemistry , Analysis of Variance , Chromatography, High Pressure Liquid , Hydrophobic and Hydrophilic Interactions , Parabens/analysis , Pharmaceutical Preparations/analysis , Phase Transition , Reference Standards , Reproducibility of Results , Water/chemistry , Water Pollutants, Chemical/analysis
17.
Talanta ; 191: 133-140, 2019 Jan 01.
Article in English | MEDLINE | ID: mdl-30262042

ABSTRACT

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.


Subject(s)
Cresols/urine , Magnets/chemistry , Parabens/analysis , Solid Phase Extraction/methods , Stomach Neoplasms/diagnosis , Urinalysis/methods , beta-Cyclodextrins/chemistry , Adsorption , Biomarkers, Tumor/isolation & purification , Biomarkers, Tumor/urine , Cresols/isolation & purification , Early Detection of Cancer , Humans , Hydrogen-Ion Concentration , Kinetics , Limit of Detection , Parabens/isolation & purification , Porosity , Stomach Neoplasms/urine
18.
J Sep Sci ; 41(15): 3105-3112, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29873179

ABSTRACT

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.


Subject(s)
Acetic Anhydrides/chemistry , Liquid Phase Microextraction , Parabens/isolation & purification , Xylenes/chemistry , Air , Cosmetics/chemistry , Food Contamination/analysis , Occupational Health , Parabens/chemistry , Water/chemistry , Water Pollutants, Chemical/chemistry
19.
J Chromatogr A ; 1564: 102-109, 2018 Aug 24.
Article in English | MEDLINE | ID: mdl-29907412

ABSTRACT

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.


Subject(s)
Magnetics , Nanotubes, Carbon/chemistry , Parabens/isolation & purification , Solid Phase Extraction/methods , Urine/chemistry , Water/chemistry , Acetylation , Adsorption , Calibration , Gas Chromatography-Mass Spectrometry , Humans , Limit of Detection , Reproducibility of Results , Solvents/chemistry
20.
Anal Chim Acta ; 1025: 124-133, 2018 Sep 26.
Article in English | MEDLINE | ID: mdl-29801601

ABSTRACT

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 (R2 ≥ 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%.


Subject(s)
Chemical Fractionation/methods , Ketones/chemistry , Metal-Organic Frameworks/chemistry , Parabens/analysis , Polyethylene Glycols/chemistry , Tandem Mass Spectrometry/methods , Adsorption , Animals , Benzophenones , Chromatography, High Pressure Liquid/methods , Cosmetics/analysis , Limit of Detection , Parabens/isolation & purification , Plasma/chemistry , Polymers , Rabbits , Reproducibility of Results
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