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1.
Int J Biol Macromol ; 155: 1019-1029, 2020 Jul 15.
Article in English | MEDLINE | ID: mdl-31715227

ABSTRACT

Recently, the presence of endocrine disrupting compounds in the environment has emerged as a global and ubiquitous problem. In this study, a novel synthesis of magnetically carbon nanotube modified with biological polymeric was successfully prepared. The effect of different parameters on the Bisphenol A (BPA) adsorption was studied. A prediction model for BPA adsorption was extended based on the Central Composite Design. Also, the prepared biopolymeric nanotubes were characterized by FT-IR, XRD, TEM, FE-SEM. The surface morphology of nanocomposite was observed, increased carbon nano tube size, and the levels after surface deposition were completely covered by chitosan proteins. The results of our experiments showed that optimum adsorption conditions was achieved at t = 76 min, BPA concentration 6.5 mg/L, adsorbent dosage 1 g/L and pH = 6.2.The data obtained in this study followed the Langmuir isotherm model and the pseudo-second order model. The maximum monolayer adsorption capacity of nanocomposite for BPA was 46.2 mg/g at 20 °C. This study showed that the adsorption of BPA onto nanocomposite was spontaneous and thermodynamically desirable.


Subject(s)
Benzhydryl Compounds/isolation & purification , Chitosan/chemistry , Endocrine Disruptors/isolation & purification , Estrogens, Non-Steroidal/isolation & purification , Nanotubes, Carbon/chemistry , Phenols/isolation & purification , Water Pollutants, Chemical/isolation & purification , Water Purification/methods , Adsorption , Benzhydryl Compounds/chemistry , Endocrine Disruptors/chemistry , Estrogens, Non-Steroidal/chemistry , Humans , Kinetics , Magnetics , Phenols/chemistry , Water Pollutants, Chemical/chemistry
2.
Toxins (Basel) ; 11(11)2019 11 18.
Article in English | MEDLINE | ID: mdl-31752226

ABSTRACT

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin and constitutes a potential health threat to humans and livestock. This study aimed to explore the potential of albite modified by the cationic surfactant cetylpyridinium chloride (CPC) as ZEN adsorbent. The organoalbite (OA) was characterized by SEM analysis, XRD analysis, FTIR spectroscopy, thermal analysis, and BET gas sorption measurement. In vitro adsorption of ZEN by OA was carried out by simulating the pH conditions of the gastrointestinal tract. The characterization results showed that the surface of OA changed from hydrophilic to hydrophobic after modification. Adsorption kinetic studies showed that ZEN adsorption behavior of OA occurred by chemisorption. The equilibrium adsorption data fitted well with the Langmuir isotherm, indicating that the adsorption process of ZEN by OA was monolayer. The maximum adsorption capacity (qm) values of OA for ZEN were 10.580 and 9.287 mg/g at pH 7 and pH 3, respectively. In addition, OA had a low desorption rate (about 2%), and co-existing amino acids (i.e., Lys and Met), vitamins (i.e., VB1 and VE), and minerals (i.e., Fe2+ and Ca2+) did not affect the removal of ZEN. These results demonstrate that OA could be a promising mycotoxin adsorbent for removing the hydrophobic, weakly polar ZEN.


Subject(s)
Cetylpyridinium/chemistry , Estrogens, Non-Steroidal/chemistry , Zearalenone/chemistry , Adsorption , Estrogens, Non-Steroidal/isolation & purification , Kinetics , Microscopy, Electron, Scanning , Spectroscopy, Fourier Transform Infrared , X-Ray Diffraction , Zearalenone/isolation & purification
3.
Talanta ; 178: 441-448, 2018 Feb 01.
Article in English | MEDLINE | ID: mdl-29136846

ABSTRACT

Bisphenols (BPs) are a family of chemicals with known endocrine disrupting activity. Bisphenol A (BPA) is the most representative prototype of this group of chemicals. Recently, the use of BPA, a prototype of endocrine disruptors, has been reduced and replaced with structural analogs due to its negative effects on both the environment and consumers. In this work, a new method is presented for the determination of seven BPs, with estrogenic activity in ready-to-eat plastic packaged baby foods. The procedure involves the isolation of the analytes using solid-liquid phase extraction with acetonitrile followed by a clean-up step with a mixture of dispersive-SPE sorbents (C18 and PSA) and magnesium sulphate, to reduce matrix effect from proteins, sugars and lipids. Extraction parameters were optimized using multivariate optimization methods. The compounds were detected and quantified by gas chromatography tandem mass spectrometry (GC-MS/MS). The limits of quantification were between 0.1 and 1.2ngg-1 for the studied analytes. The method was validated using matrix-matched calibration and recovery assays with spiked samples. Recovery rates were between 91% and 110% and % RSD was lower than 13% in all cases. The method has been successfully applied for the determination of these endocrine disrupting chemicals (EDCs) in samples of a novel type of food consumed by pre-schoolers. This is the first study to analyze EDCs in plastic packaged foods consumed by this target group.


Subject(s)
Benzhydryl Compounds/analysis , Chemical Fractionation/methods , Food Packaging , Gas Chromatography-Mass Spectrometry/methods , Infant Food/analysis , Phenols/analysis , Plastics , Tandem Mass Spectrometry/methods , Acetonitriles/chemistry , Benzhydryl Compounds/isolation & purification , Endocrine Disruptors/analysis , Endocrine Disruptors/isolation & purification , Estrogens, Non-Steroidal/analysis , Estrogens, Non-Steroidal/isolation & purification , Food Contamination/analysis , Humans , Infant , Limit of Detection , Linear Models , Magnesium Sulfate/chemistry , Phenols/isolation & purification , Sodium Chloride/chemistry , Solvents/chemistry , Time Factors , Water/chemistry
4.
Article in English | MEDLINE | ID: mdl-27249165

ABSTRACT

Electrochemical polymerization of luminol molecularly imprinted polymer on carboxyl graphene (MIP/CG) was developed as stir bar sorptive extraction (SBSE) coating for selective pre-concentration and specific recognition of bisphenol A (BPA), hexoestrol and diethylstilbestrol in milk samples. Luminol was employed as monomer and BPA as the template to prepare MIP under 0-0.6V electro-polymerization. Carboxyl graphene was modified on pencil lead as the substrate to increase extraction capacity. The preparation and extraction conditions affecting the extraction efficiency were optimized. Under the optimized conditions, a good linearity of three estrogens was obtained in the range of 4-1000ngmL(-1). The average recoveries at the three spiked levels of the three estrogens ranged from 83.4% to 96.3% with the relative standard deviations (RSD)≤7.1%. The limits of detection were in the range of 0.36-1.09ngmL(-1). The developed method with low cost, high selectivity and good reproducibility can be potentially applied for determining trace estrogens in complex food samples.


Subject(s)
Estrogens, Non-Steroidal/isolation & purification , Food Analysis/methods , Luminol/chemistry , Milk/chemistry , Molecular Imprinting/methods , Polymers/chemistry , Adsorption , Animals , Benzhydryl Compounds/isolation & purification , Diethylstilbestrol/isolation & purification , Electroplating/methods , Graphite/chemistry , Hexestrol/isolation & purification , Limit of Detection , Phenols/isolation & purification , Polymerization , Solid Phase Extraction/methods
5.
Anal Chim Acta ; 853: 342-350, 2015 Jan 01.
Article in English | MEDLINE | ID: mdl-25467478

ABSTRACT

A novel 8-electrode array as stir bar was designed for selective extraction of trace level exogenous estrogens from food samples, followed by liquid desorption and HPLC-photodiode array detection. The array consisted of 8 screen-printed electrodes and each electrode was modified with Fe3O4@meso-/macroporous TiO2 microspheres and molecularly imprinted film (m-TiMIF). The fabrication of the imprinted film coating was very simple without organic solvents and chemical grafting. Both bisphenol A (BPA) and diethylstilbestrol (DES) were employed as templates in m-TiMIF fabrication in order to enrich both targets simultaneously. Interestingly, the imprinted stir bar array showed higher extraction capacity and selectivity for BPA and DES than the non-imprinted counterpart. Meanwhile, it exhibited fast adsorption and desorption kinetics due to increased mass transport in the ultra-thin film. Importantly, the m-TiMIF coating was robust enough for at least 20 uses without obvious alteration in extraction performance. The main parameters affecting the extraction efficiency, including stir speeding, sample pH, ionic strength, extraction time, desorption solvent and time, were optimized. Under optimal experimental conditions, the limits of detection (S/N=3) of the developed method were 0.28 and 0.47 µg L(-1) for BPA and DES respectively, with enrichment factors of 32.6 and 52.8-fold. The linear ranges were 3.0-1500 µg L(-1) and 4.0-1500 µg L(-1) for BPA and DES, respectively. The m-TiMIF-coating conferred better recovery and selectivity, compared with the commercial stir bar coating. The new method was successfully applied to assess BPA and DES in pork and chicken samples with satisfactory recovery.


Subject(s)
Analytic Sample Preparation Methods/instrumentation , Benzhydryl Compounds/isolation & purification , Diethylstilbestrol/isolation & purification , Estrogens, Non-Steroidal/isolation & purification , Meat/analysis , Molecular Imprinting , Phenols/isolation & purification , Solid Phase Extraction/instrumentation , Adsorption , Benzhydryl Compounds/analysis , Benzhydryl Compounds/chemistry , Diethylstilbestrol/analysis , Diethylstilbestrol/chemistry , Electrodes , Estrogens, Non-Steroidal/analysis , Estrogens, Non-Steroidal/chemistry , Food Contamination/analysis , Limit of Detection , Microspheres , Phenols/analysis , Phenols/chemistry , Porosity , Reproducibility of Results , Titanium/chemistry
6.
Article in English | MEDLINE | ID: mdl-25421274

ABSTRACT

A sensitive and selective GC-MS method was developed and used to analyse human milk samples for both free and total bisphenol A (BPA). Total BPA was detected in 72 of the 278 human milk samples (25.9%) at concentrations from < 0.036 to 2.5 ng g(-1) with a geometric mean (GM) of 0.13 ng g(-1) and median of 0.11 ng g(-1), while free BPA was detected in fewer samples, 46 of the 278 samples (16.5%) at concentrations ranging from < 0.036 to 2.3 ng g(-1) with a GM of 0.11 ng g(-1) and median of 0.10 ng g(-1). Ratios of [free BPA]/[total BPA] for the positive samples ranged from 7.9% to 100% with a GM of 57.2% and median of 70.3%. Concentrations of free and total BPA in most samples were low with 0.39 and 0.65 ng g(-1) at the 95th percentile for free and total BPA, respectively, and they are also lower than those reported in other countries. Based on the low frequency of detection of free BPA in human milk samples, in general, dietary exposure to BPA for Canadian breast-fed infants is expected to be somewhat lower compared with exposure among formula-fed infants.


Subject(s)
Benzhydryl Compounds/isolation & purification , Environmental Pollutants/isolation & purification , Estrogens, Non-Steroidal/isolation & purification , Gas Chromatography-Mass Spectrometry/methods , Infant Formula/chemistry , Milk, Human/chemistry , Phenols/isolation & purification , Adult , Breast Feeding , Canada , Female , Humans , Infant , Infant, Newborn , Lactation/physiology , Sensitivity and Specificity
7.
J Chromatogr A ; 1368: 18-25, 2014 Nov 14.
Article in English | MEDLINE | ID: mdl-25441340

ABSTRACT

A modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method based on the dispersive solid-phase extraction (dSPE) combined with high performance liquid chromatography (HPLC) was developed for the determination of non-steroidal estrogens in water samples. In this study, graphene oxide-based silica microspheres (SiO2@GO) were used as dSPE material for the preconcentration of analytes. HPLC was used for the separation and detection. This was the first time that the synthesized SiO2@GO microspheres were used as stationary phases for the off-line preconcentration of the non-steroidal estrogens in dSPE. dSPE parameters, such as sample pH, volume and type of eluent were optimized. Application of the developed method to analyze spiked lake, reservoir and tap water samples resulted in good recoveries values ranging from 70 to 106% with relative standard deviation values lower than 7.0% in all cases. Limits of detection were in the range of 0.2-6.1 µg/L. The combined data obtained in this study recommended that the proposed method is very fast, simple, repeatable and accurate for the detection of non-steroidal estrogens. Furthermore, the SiO2@GO microspheres application could potentially be expanded to extract and pre-concentrate other compounds in various matrices.


Subject(s)
Estrogens, Non-Steroidal/isolation & purification , Graphite/chemistry , Microspheres , Solid Phase Extraction/methods , Chromatography, High Pressure Liquid/methods , Oxides/chemistry , Temperature , Water/chemistry
8.
Talanta ; 120: 255-61, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24468367

ABSTRACT

Improving the site accessibility of molecularly imprinted polymer (MIP) is one of the biggest challenges for application of MIP in solid-phase extraction (SPE). Hierarchically imprinted mesoporous silica polymer was prepared with semicovalently bond imprinting methods based on MCM-41 and SBA-15 mesostructures, aiming to improve the site accessibility of MIP and increase the efficiency of molecularly imprinted-SPE. Characterization and performance tests of the obtained products revealed that molecularly imprinted SBA-15 (MIP-SBA-15) not only retained the mesoporous structure of SBA-15, but also displayed excellent selectivity of MIP to the target molecule. As the MIP-SBA-15 were adopted as the adsorbents of solid-phase extraction for detecting bisphenol A in spiked water samples, the recoveries of spiked samples more than 87%, which reveals that the molecularly imprinted SBA-15 were efficient SPE adsorbents for bisphenol A.


Subject(s)
Benzhydryl Compounds/isolation & purification , Molecular Imprinting/methods , Phenols/isolation & purification , Silicon Dioxide/chemistry , Solid Phase Extraction/methods , Water Pollutants, Chemical/isolation & purification , Adsorption , Chromatography, High Pressure Liquid , Estrogens, Non-Steroidal/isolation & purification , Porosity , Water/analysis
9.
J Chromatogr A ; 1307: 41-8, 2013 Sep 13.
Article in English | MEDLINE | ID: mdl-23921262

ABSTRACT

A simple and cost-effective pre-treatment procedure was developed for six resorcylic acid lactones (RALs) in feed using dispersive solid phase extraction (dSPE) with multi-walled carbon nanotubes (MWCNTs). The sample was analysed after purification by ultra-high performance liquid chromatography-negative electrospray ionisation tandem mass spectrometry (UHPLC-ESI-MS/MS). After extraction with acetonitrile/water (80:20, v/v) and dilution with water, a dSPE procedure was carried out with MWCNTs. The pH value of the extract, the extraction time for MWCNTs, the type and amount of MWCNTs and the type of eluent were optimised to increase the sample throughput and the sensitivity. The samples were quantified using the internal standard zearalenone-D6. The absolute recoveries of the target compounds from feed samples were most efficient when using 100mg of MWCNTs with an outer diameter of less than 8nm and a length of 10-30µm, and ethyl acetate was shown to be the most suitable solvent for desorbing the target compounds from the MWCNTs. The mean recoveries from fortified swine mixed feed samples ranged from 95.3% to 107.2% and had relative standard deviations lower than 10%; the limits of detection and quantification for RALs were in the ranges of 0.20-0.29µg/kg and 0.54-0.78µg/kg, respectively.


Subject(s)
Chromatography, Liquid/methods , Estrogens, Non-Steroidal/analysis , Solid Phase Extraction/methods , Tandem Mass Spectrometry/methods , Zearalenone/analogs & derivatives , Zearalenone/analysis , Zeranol/analogs & derivatives , Acetates/chemistry , Acetonitriles/chemistry , Animal Feed/analysis , Estrogens, Non-Steroidal/chemistry , Estrogens, Non-Steroidal/isolation & purification , Hydrogen-Ion Concentration , Limit of Detection , Linear Models , Nanotubes, Carbon/chemistry , Reproducibility of Results , Zearalenone/chemistry , Zearalenone/isolation & purification , Zeranol/analysis , Zeranol/chemistry , Zeranol/isolation & purification
10.
Water Sci Technol ; 68(3): 567-74, 2013.
Article in English | MEDLINE | ID: mdl-23925184

ABSTRACT

Wastewater treatment plant (WWTP) effluents are considered to be a major source for the release in the aquatic environment of endocrine-disrupting compounds (EDCs). Ozone has proved to be a suitable solution for polishing secondary domestic effluents. In this work, the performance of a full-scale ozonation plant was investigated in order to assess the removal efficiency of four target EDCs: nonylphenol, nonylphenol monoethoxylate, nonylphenol diethoxylate and bisphenol A. The studied system was the tertiary treatment stage of a municipal WWTP which receives an important industrial (textile) load. Chemical analyses showed that the considered substances occurred with a significant variability, typical of real wastewaters; based on this, ozonation performance was carefully evaluated and it appeared to be negatively affected by flow-rate increase (during rainy days, with consequent contact time reduction). Moreover, EDCs' measured removal efficiency was lower than what could be predicted based on literature data, because of the relatively high residual content of biorefractory compounds still present after biological treatment.


Subject(s)
Benzhydryl Compounds/isolation & purification , Estrogens, Non-Steroidal/isolation & purification , Ozone/chemistry , Phenols/isolation & purification , Waste Disposal, Fluid/methods , Wastewater/chemistry , Benzhydryl Compounds/analysis , Benzhydryl Compounds/chemistry , Endocrine Disruptors/analysis , Endocrine Disruptors/chemistry , Endocrine Disruptors/isolation & purification , Estrogens, Non-Steroidal/analysis , Estrogens, Non-Steroidal/chemistry , Phenols/analysis , Phenols/chemistry , Water Pollutants, Chemical/analysis , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/isolation & purification , Water Purification/methods
11.
PLoS One ; 7(3): e33186, 2012.
Article in English | MEDLINE | ID: mdl-22427984

ABSTRACT

Single chain variable fragments (scFvs) against diethylstilbestrol (DES) were selected from the splenocytes of non-immunized mice by ribosome display technology. A naive library was constructed and engineered to allow in vitro transcription and translation using an E. coli lysate system. Alternating selection in solution and immobilization in microtiter wells was used to pan mRNA-ribosome-antibody (ARM) complexes. After seven rounds of ribosome display, the expression vector pTIG-TRX containing the selected specific scFv DNAs were transformed into Escherichia coli BL21 (DE3) for expression. Twenty-six positive clones were screened and five clones had high antibody affinity and specificity to DES as evidenced by indirect competitive ELISA. Sequence analysis showed that these five DES-specific scFvs had different amino acid sequences, but the CDRs were highly similar. Surface plasmon resonance (SPR) analysis was used to determine binding kinetics of one clone (30-1). The measured K(D) was 3.79 µM. These results indicate that ribosome display technology can be used to efficiently isolate hapten-specific antibody (Ab) fragments from a naive library; this study provides a methodological framework for the development of novel immunoassays for multiple environmental pollutants with low molecular weight detection using recombinant antibodies.


Subject(s)
Diethylstilbestrol/isolation & purification , Environmental Pollutants/isolation & purification , Estrogens, Non-Steroidal/isolation & purification , Immunoassay/methods , Macromolecular Substances/immunology , Amino Acid Sequence , Animals , Antibody Specificity , Base Sequence , Diethylstilbestrol/immunology , Electrophoresis, Agar Gel , Environmental Pollutants/immunology , Enzyme-Linked Immunosorbent Assay , Escherichia coli , Estrogens, Non-Steroidal/immunology , Female , Genetic Vectors , Mice , Molecular Sequence Data , Peptide Library , Ribosomes/immunology , Sequence Analysis, DNA , Single-Chain Antibodies/genetics , Single-Chain Antibodies/immunology , Spleen/cytology , Spleen/immunology , Surface Plasmon Resonance
12.
J Chromatogr A ; 1223: 1-8, 2012 Feb 03.
Article in English | MEDLINE | ID: mdl-22227360

ABSTRACT

A fast, simple, sensitive and green analytical chemistry method for the simultaneous determination of alkylphenols (4-tert-octylphenol, 4-octylphenol, 4-n-nonylphenol, nonylphenol) and bisphenol A in seawater was developed and validated. The procedure was based on a dispersive liquid-liquid microextraction (DLLME) of a small volume of seawater sample (30 mL) using only 100 µL of 1-octanol, combined with liquid chromatography-electrospray ionization tandem mass spectrometry in negative mode (LC-ESI-MS/MS). The matrix effect was studied and compensated using deuterated labelled standards as surrogate standards for the quantitation of target compounds. The analytical features of the proposed method were satisfactory: repeatability and intermediate precision were <10% and recoveries were around 84-104% for all compounds. Uncertainty assessment of measurement was estimated on the basis of an in-house validation according to EURACHEM/CITAC guide. Quantitation limits of the method (MQL) ranged between 0.005 and 0.03 µg L⁻¹, therefore the levels established in the Directive 2008/105/EC were achieved. The applicability of the proposed method was demonstrated analyzing seawater samples from different sites of A Coruña (Northwest of Spain). The analyses showed the presence of all compounds at levels between 0.035 (bisphenol A) and 0.14 µg L⁻¹ (nonylphenol).


Subject(s)
Liquid Phase Microextraction/methods , Phenols/analysis , Seawater/analysis , Spectrometry, Mass, Electrospray Ionization/methods , Water Pollutants, Chemical/analysis , Benzhydryl Compounds , Estrogens, Non-Steroidal/analysis , Estrogens, Non-Steroidal/isolation & purification , Phenols/isolation & purification , Reproducibility of Results , Sensitivity and Specificity , Spain , Tandem Mass Spectrometry/methods , Water Pollutants, Chemical/isolation & purification
13.
Anal Bioanal Chem ; 401(5): 1695-701, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21744235

ABSTRACT

A simple and rapid analytical method based on in-matrix ethyl chloroformate (ECF) derivatization has been developed for the quantitative determination of bisphenol-A (BPA) in milk and water samples. The samples containing BPA were derivatised with ECF in the presence of pyridine for 20 s at room temperature, and the non-polar derivative thus formed was extracted using polydimethylsiloxane solid-phase microextraction (SPME) fibres with thicknesses of 100 µm followed by analysis using gas chromatography-mass spectrometry. Three alkyl chloroformates (methyl, ethyl and isobutyl chloroformate) were tested for optimum derivatisation yields, and ECF has been found to be optimum for the derivatisation of BPA. Several parameters such as amount of ECF, pyridine and reaction time as well as SPME parameters were studied and optimised in the present work. The limit of detection for BPA in milk and water samples was found to be 0.1 and 0.01 µg L(-1), respectively, with a signal-to-noise ratio of 3:1. The limit of quantitation for BPA in milk and water was found to be 0.38 and 0.052 µg L(-1), respectively, with a signal-to-noise ratio of 10:1. In conclusion, the method developed was found to be rapid, reliable and cost-effective in comparison to silylation and highly suitable for the routine analysis of BPA by various food and environmental laboratories.


Subject(s)
Estrogens, Non-Steroidal/analysis , Formic Acid Esters/chemistry , Milk/chemistry , Phenols/analysis , Water/analysis , Air Pollutants, Occupational/analysis , Air Pollutants, Occupational/isolation & purification , Animals , Benzhydryl Compounds , Estrogens, Non-Steroidal/isolation & purification , Gas Chromatography-Mass Spectrometry/economics , Gas Chromatography-Mass Spectrometry/methods , Limit of Detection , Phenols/isolation & purification , Solid Phase Microextraction/economics , Solid Phase Microextraction/methods
14.
Anal Chim Acta ; 637(1-2): 47-54, 2009 Apr 01.
Article in English | MEDLINE | ID: mdl-19286011

ABSTRACT

The presence of zeranol (alpha-zearalanol) in urine samples due to natural contamination or illegal treatment is under debate within the European Union. The simultaneous determination of zeranol, its epimer taleranol (beta-zearalanol), zearalanone and the structurally related mycotoxin zearalenone with the corresponding alpha- and beta-zearalenol metabolites appears to be critical in deciding whether an illegal use has occurred. The aim of this study is to develop and validate a simple analytical procedure applicable to bovine and swine urine samples for the determination of all six resorcylic acid lactones. After an enzymatic deconjugation, the urine was subjected to a one-step cleanup on a commercially available immunoaffinity chromatography cartridge. The analytes were detected by liquid chromatography-negative-ion electrospray tandem mass spectrometry using deuterium-labelled internal standards. The method was validated as a quantitative confirmatory method according to European Commission Decision 2002/657/EC. The evaluated parameters were: linearity, specificity, precision (repeatability and intra-laboratory reproducibility), recovery, decision limit, detection capability and ruggedness. The decision limits (CCalpha) obtained, were between 0.56 and 0.68 microgL(-1); recovery above 66% for all the analytes. Repeatability was between 1.4 and 5.3% and within-laboratory reproducibility between 1.9 and 16.1% for the six resorcylic acid lactones.


Subject(s)
Chromatography, Affinity/methods , Chromatography, High Pressure Liquid/methods , Estrogens, Non-Steroidal/urine , Substance Abuse Detection/methods , Tandem Mass Spectrometry/methods , Zeranol/urine , Animals , Cattle , Estrogens, Non-Steroidal/isolation & purification , Reproducibility of Results , Swine , Zearalenone/isolation & purification , Zearalenone/urine , Zeranol/isolation & purification
15.
Chemosphere ; 70(1): 119-25, 2007 Nov.
Article in English | MEDLINE | ID: mdl-17675209

ABSTRACT

Endocrine disrupting chemicals (EDCs) can alter endocrine function in exposed animals. Such critical effects, combined with the ubiquity of EDCs in sewage effluent and potentially in tapwater, have led to concerns that they could be major physiological disruptors for wildlife and more controversially for humans. Although sewage effluent is known to be a rich source of EDCs, there is as yet no evidence for EDC uptake by invertebrates that live within the sewage treatment system. Here, we describe the use of an extraction method and GC-MS for the first time to determine levels of EDCs (e.g., dibutylphthalate, dioctylphthalate, bisphenol-A and 17beta-estradiol) in tissue samples from earthworms (Eisenia fetida) living in sewage percolating filter beds and garden soil. To the best of our knowledge, this is the first such use of these techniques to determine EDCs in tissue samples in any organism. We found significantly higher concentrations of these chemicals in the animals from sewage percolating filter beds. Our data suggest that earthworms can be used as bioindicators for EDCs in these substrates and that the animals accumulate these compounds to levels well above those reported for waste water. The potential transfer into the terrestrial food chain and effects on wildlife are discussed.


Subject(s)
Endocrine Disruptors/metabolism , Oligochaeta/metabolism , Sewage/analysis , Water Pollutants, Chemical/metabolism , Animals , Biofilms , Chromatography, Gel , Estrogens, Non-Steroidal/analysis , Estrogens, Non-Steroidal/isolation & purification , Hormones/analysis , Reference Standards , Soil/analysis
16.
Anal Bioanal Chem ; 385(7): 1155-61, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16628404

ABSTRACT

A molecularly imprinted polymer prepared using 1-allylpiperazine (1-ALPP) as the functional monomer, trimethyltrimethacrylate (TRIM) as the crosslinker and the zearalenone (ZON)-mimicking template cyclododecanyl-2,4-dihydroxybenzoate (CDHB) has been applied to the clean-up and preconcentration of this mycotoxin (zearalenone) and a related metabolite, alpha-zearalenol (alpha-ZOL), from cereal and swine feed sample extracts. The extraction of ZON and alpha-ZOL from the food samples was accomplished using pressurized liquid extraction (PLE) with MeOH/ACN (50:50, v/v) as the extraction solvent, at 50 degrees C and 1500 psi. The extracted samples were cleaned up and preconcentrated through the MIP cartridge and analyzed using HPLC with fluorescence detection (lambda (exc)=271/ lambda (em)=452 nm). The stationary phase was a polar endcapped C18 column, and ACN/MeOH/water 10/55/35 (v/v/v, 15 mM ammonium acetate) at a flow rate of 1.0 mL min(-1) was used as the mobile phase. The method was applied to the analysis of ZON and alpha-ZOL in wheat, corn, barley, rye, rice and swine feed samples fortified with 50, 100 and 400 ng g(-1) of both mycotoxins, and it gave recoveries of between 85 and 97% (RSD 2.1-6.7%, n=3) and 87-97% (RSD 2.3-5.6%, n=3) for alpha-ZOL and ZON, respectively. The method was validated using a corn reference material for ZON.


Subject(s)
Animal Feed/standards , Edible Grain/standards , Estrogens, Non-Steroidal/isolation & purification , Polymers , Zearalenone/isolation & purification , Zeranol/analogs & derivatives , Animals , Food Contamination , Methods , Molecular Conformation , Swine , Zeranol/isolation & purification
17.
Environ Sci Technol ; 39(16): 6246-50, 2005 Aug 15.
Article in English | MEDLINE | ID: mdl-16173588

ABSTRACT

The present study aimed to analyze the behavior of different activated carbons in the adsorption and removal of bisphenol A (2-2-bis-4-hydroxypheniyl propane) from aqueous solutions in order to identify the parameters that determine this process. Two commercial activated carbons and one prepared in our laboratory from almond shells were used; they were texturally and chemically characterized, obtaining the surface area, pore size distribution, mineral matter content, elemental analysis, oxygen surface groups, and pH of the point of zero charge (pH(PZC)), among other parameters. Adsorption isotherms of bisphenol A and adsorption capacities were obtained. The capacity of the carbons to remove bisphenol A was related to their characteristics. Thus, the adsorption of bisphenol A on activated carbon fundamentally depends on the chemical nature of the carbon surface and the pH of the solution. The most favorable experimental conditions for this process are those in which the net charge density of the carbon is zero and the bisphenol A is in molecular form. Under these conditions, the adsorbent-adsorbate interactions that govern the adsorption mechanism are enhanced. Influences of the mineral matter present in the carbon samples and the solution chemistry (pH and ionic strength) were also analyzed. The presence of mineral matter in carbons reduces their adsorption capacity because of the hydrophilic nature of the matter. The presence of electrolytes in the solution favor the adsorption process because of the screening effect produced between the positively charged carbon surface and the bisphenol A molecules, with a resulting increase in adsorbent-adsorbate interactions.


Subject(s)
Carbon/chemistry , Estrogens, Non-Steroidal/isolation & purification , Phenols/isolation & purification , Water Purification/methods , Adsorption , Benzhydryl Compounds , Estrogens, Non-Steroidal/chemistry , Hydrogen-Ion Concentration , Phenols/chemistry
18.
J Nat Prod ; 67(12): 2024-32, 2004 Dec.
Article in English | MEDLINE | ID: mdl-15620245

ABSTRACT

Estrogenicity-directed fractionation of a methanol extract of the strobiles of Humulus lupulus that had been extracted previously with supercritical CO(2), known as "spent hops", led to the isolation and identification of 22 compounds including 12 prenylated chalcones (1-8, 10-13), five prenylflavanones (14-17), 4-hydroxybenzaldehyde (18), sitosterol-3-O-beta-glucopyranoside (19), humulinone (20), and cohumulinone (21). In addition, the prenylated chalcone xanthohumol C (9a) was obtained as a 6:1 mixture along with its 1' ',2' '-dihydro derivative (9b). Three new chalcones (4, 11, 12) and four previously unreported constituents of hops (5, 6, 9b, 13) are reported. The structures of the new compounds were determined through a combination of spectrometric techniques including 1D and 2D NMR, HRESIMS, and ESIMS-MS. Full 1H NMR spin system analyses were performed to characterize the higher-order glucopyranosyl, prenyl, and chalcone B-ring spectra of the isolates. The principle estrogen 8-prenylnaringenin (15) from hops is an artifact formed along with its positional isomer 6-prenylnaringenin (16) through the spontaneous isomerization of the pro-estrogenic chalcone DMX (7).


Subject(s)
Estrogens, Non-Steroidal/isolation & purification , Flavonoids/isolation & purification , Humulus/chemistry , Alkaline Phosphatase/metabolism , Estrogens, Non-Steroidal/chemistry , Estrogens, Non-Steroidal/pharmacology , Flavonoids/chemistry , Flavonoids/pharmacology , Humans , Molecular Conformation , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Phytoestrogens , Tumor Cells, Cultured
19.
Chemosphere ; 55(6): 927-31, 2004 May.
Article in English | MEDLINE | ID: mdl-15041297

ABSTRACT

Fifteen trace impurities, including a novel cyclohexene derivative, have been identified and quantified in samples of an industrial grade of the oestrogen-active compound 4,4'-isopropylidene diphenol (bisphenol A). All of these compounds, like bisphenol A itself, possess phenolic hydroxyl groups para to other substituents and all thus might also have oestrogenic properties. Published studies on the endocrine disrupting properties of bisphenol A have not considered potentially active impurities but full assessment of the oestrogenicity of bisphenol A, as it is used commercially, will become possible when adequate supplies of these compounds are available through synthesis.


Subject(s)
Estrogens, Non-Steroidal/chemistry , Estrogens, Non-Steroidal/isolation & purification , Phenols/chemistry , Phenols/isolation & purification , Benzhydryl Compounds , Chromatography , Structure-Activity Relationship
20.
Phytochemistry ; 65(2): 233-41, 2004 Jan.
Article in English | MEDLINE | ID: mdl-14732284

ABSTRACT

During recent years, phytoestrogens have been receiving an increasing amount of interest, as several lines of evidence suggest a possible role in preventing a range of diseases, including the hormonally dependent cancers. In this context, various parts of the pomegranate fruit (Punica granatum; Punicaceae), e.g. seed oil, juice, fermented juice and peel extract, have been shown to exert suppressive effects on human breast cancer cells in vitro. On-line biochemical detection coupled to mass spectrometry (LC-BCD-MS) was applied to rapidly profile the estrogenic activity in the pomegranate peel extract. The crude mixture was separated by HPLC, after which the presence of biologically active compounds, known or unknown, was detected by means of an on-line beta-estrogen receptor (ER) bioassay. Chemical information, such as molecular weight and MS/MS fingerprint, was obtained in real time by directing part of the HPLC effluent towards a mass spectrometer. Using this approach in total three estrogenic compounds, i.e. luteolin, quercetin and kaempferol, were detected and identified by comparing the obtained molecular weights and negative ion APCI MS/MS spectra with the data of an estrogenic compound library. Although well known in literature and widely distributed in nature, the presence of these phytoestrogenic compounds in pomegranate peel extract was not reported previously. Compared to traditional screening approaches of complex mixtures, often characterized by a repeating cycle of HPLC fractionation and biological screening, LC-BCD-MS was shown to profoundly accelerate the time required for compound description and identification.


Subject(s)
Estrogens, Non-Steroidal/isolation & purification , Lythraceae/chemistry , Chromatography, High Pressure Liquid/instrumentation , Chromatography, High Pressure Liquid/methods , Flavonoids/isolation & purification , Glycosylation , Kaempferols/isolation & purification , Luteolin , Mass Spectrometry/methods , Plant Extracts/chemistry , Quercetin/isolation & purification
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