Analysis of endocrine disrupting alkylphenols, chlorophenols and bisphenol-A using hollow fiber-protected liquid-phase microextraction coupled with injection port-derivatization gas chromatography–mass spectrometry

Bisphenol A alters sexual dimorphism and gene expression in marine medaka Oryzias melastigma

Bisphenol A (BPA) is an endocrine disruptor that is present in freshwater and marine environments. However, conclusive evidence for the toxicity of chronic BPA exposure to marine fishes remains lacking. Therefore, we investigated the influence of BPA on male marine medaka (Oryzias melastigma). BPA exposure induced formation of testis-ova at 2610 µg/L, and male-type anal fins became more female type in a concentration-dependent manner. Some males with female-type anal fins had normal testes, indicating that anal fin shape is more sensitive to BPA. Gonadal soma-derived factor (gsdf) expression decreased after BPA exposure in the 746 and 2610 µg/L exposure groups, although the changes were not statistically significant. Additionally, liver vitellogenin (vtg) expression increased in a dose-dependent manner and was significantly higher in all exposure groups. vtg and gsdf are likely to be useful biomarkers for the impact of estrogenic endocrine disrupters in O. melastigma.

Determination of UV Filters in Waste Sludge Using QuEChERS Method Followed by In-Port Derivatization Coupled with GC-MS/MS

UV filters (UVFs) are widely used in personal care and in industrial products for protection against photodegradation. In recent years, their potential toxicological and environmental effects have received growing attention. Due to their excessive use, their residue levels in the environment are gradually increasing and they tend to accumulate on biological wastewater treatment sludge. The utilization of sludge as fertilizer could be one of the main routes of UVF contamination in the environment. Therefore, the development of a reliable and sensitive method of analyzing their trace level residues in waste sludge samples is of great importance. The success of the method largely depends on the sample preparation technique in such complex matrices. This study presents a rapid, sensitive and green analysis method for eight UVFs in sludge samples, selected for their rather low no-observed-effect concentrations (NOEC). For this purpose, the QuEChERS methodology was coupled with in-port derivatization for subsequent detection of the targeted UVFs via GC−MS/MS. The analysis time was substantially shortened using this method, and reagent utilization was also reduced. The method was validated in the sludge samples, and high recovery (66−123%) and low RSD values (<25.6%) were obtained. In addition, major contributing uncertainty sources and expanded uncertainties were determined.

Performance of a dual-chamber microbial fuel cell as a biosensor for in situ monitoring Bisphenol A in wastewater

This research explores the possibilities of a dual-chamber microbial fuel cell as a biosensor to measure Bisphenol A (BPA) in wastewater. BPA is an organic compound and is considered to be an endocrine disruptor, affecting exposed organisms, the environment, and human health. The performance of the microbial fuel cells (MFCs) was first controlled with specific operational conditions (pH, temperature, fuel feeding rate, and organic loading rate) to obtain the best accuracy of the sensor signal. After that, BPA concentrations varying from 50 to 1000 μg L^-1 were examined under the biosensor's cell voltage generation. The outcome illustrates that MFC generates the most power under the best possible conditions of neutral pH, 300 mg L^-1 of COD, R 1000 Ω, and ambient temperature. In general, adding BPA improved the biosensor's cell voltage generation. A slight linear trend between voltage output generation and BPA concentration was observed with R² 0.96, which indicated that BPA in this particular concentration range did not real harm to the MFC's electrogenic bacteria. Scanning electron microscope (SEM) images revealed a better cover biofilm after BPA injection on the surface electrode compared to it without BPA. These results confirmed that electroactive biofilm-based MFCs can serve to detect BPA found in wastewaters.

Recent Advances in Electrochemical Sensors and Biosensors for Detecting Bisphenol A

In recent years, several studies have focused on environmental pollutants. Bisphenol A (BPA) is one prominent industrial raw material, and its extensive utilization and release into the environment constitute an environmental hazard. BPA is considered as to be an endocrine disruptor which mimics hormones, and has a direct relationship to the development and growth of animal and human reproductive systems. Moreover, intensive exposure to the compound is related to prostate and breast cancer, infertility, obesity, and diabetes. Hence, accurate and reliable determination techniques are crucial for preventing human exposure to BPA. Experts in the field have published general electrochemical procedures for detecting BPA. The present timely review critically evaluates diverse chemically modified electrodes using various substances that have been reported in numerous studies in the recent decade for use in electrochemical sensors and biosensors to detect BPA. Additionally, the essential contributions of these substances for the design of electrochemical sensors are presented. It has been predicted that chemically modified electrode-based sensing systems will be possible options for the monitoring of detrimental pollutants.

Development and validation of GC-MS/MS method useful in diagnosing intestinal dysbiosis

Dysbiosis is a disorder of the bacterial flora of the human digestive tract. It is usually diagnosed clinically by direct detection of an abnormal pattern of the intestinal microbiota. The intermediate diagnosis based on determining the content of microflora metabolites, considered as chemical markers of this disorder, is still rarely used. This is, among others, due to the variety of properties of compounds recognised as dysbiosis markers and as a consequence, the use of different methods for their analysis. To the best of our knowledge, there is still no analytical procedure that would allow unambiguous determination of all compounds in one procedure. In the present study, we have established a detailed method for the quantitative analysis of hydrocinnamic, citramalic, p-hydroxybenzeneacetic, tartaric, hippuric, 4-hydroxybenzoic, indoxylsulfuric, tricarballylic, 3,4-dihydroxyhydrocinnamic and benzoic acids along with DL-arabitol that employs the direct derivatization of compounds in a small volume of urine sample followed by gas chromatography - tandem mass spectrometry (GC-MS/MS). To show that the optimised method is a useful tool for chemical diagnosis of dysbiosis, it was applied for determination of the dysbiosis markers in the authentic urine samples.

Adenine-functionalized polypropylene glycol: A novel stationary phase for gas chromatography offering good inertness for acids and bases combined with a unique selectivity

This work presents the investigation of utilizing adenine-functionalized polypropylene glycol (APPG) for capillary gas chromatographic separations. The statically coated APPG column (0.25 mm i.d.) showed moderate polarity and high column efficiencies of 4660 plates/m and 4376 plates/m determined by n-octanol and naphthalene, respectively. Remarkably, the APPG column baseline resolved all the components of the Grob test mixture and displayed good peak shapes for some stringent analytes that are prone to peak tailing or severe adsorption. Also, it achieved complete separation of dimethylaniline isomers, which are difficult to be resolved due to their high resemblance in structures and properties. The above results demonstrate the high selectivity and inertness of the APPG column and its distinct advantages over the polypropylene glycol (PPG) column and commercial polyethylene glycol (PEG) column. In addition, its separation performance has good repeatability with the RSD values on retention times below 0.05% for run-to-run, 0.11-0.12% for day-to-day and 1.7-1.9% for column-to-column, respectively. Further, the APPG column was applied to determination of isomer impurities in commercial dimethylaniline products and to determination of the additives of anilines and phenols in a hair-dye product, proving its great potential for practical GC analysis.

Organophosphorus flame retardants and persistent, bioaccumulative, and toxic contaminants in Arctic seawaters: On-board passive sampling coupled with target and non-target analysis

Organic pollutants in the Arctic seas have been of concern to many researchers; however, the vast dynamic marine water poses challenges to their comprehensive monitoring within appropriate spatial and temporal scales in the Arctic. In this study, on-board passive sampling of organic pollutants using a self-developed device coupled with triolein-embedded cellulose acetate membranes (TECAMs) was performed during an Arctic cruise. The TECAM extracts were used for target analysis of organophosphorus flame retardants (PFRs), and non-target screening of persistent, bioaccumulative, and toxic (PBT) contaminants using two-dimensional gas chromatography with time-of-flight mass spectrometry (GC × GC-TOFMS). Sixteen chemicals were screened out as PBT contaminants from the 1500 features in the non-target analysis and further identified. Consequently, two chlorinated PFRs (tris(chloroisopropyl)phosphate and tris(1,3-dichloroisopropyl)phosphate) and four PBT contaminants (4-tert-butylphenol, 2-isopropylnaphthalene, 1,1,3-trimethyl-3-phenylindane, and 1-phenylnonan-1-one) were accurately quantified, with the temporally and spatially integrated concentrations ranging from 0.83 ng L^-1 to 20.82 ng L^-1 in the seawaters. Sources and transport of the contaminants were studied, and ocean current transport (West Spitsbergen Current, WSC) and local sources (human settlement, Arctic oil exploitation, and petroleum fuel emissions) were found to contribute to the presence of the different contaminants. Finally, annual transport fluxes of the contaminants from the North Atlantic to the Arctic Ocean by WSC were estimated, and the results indicate that their hazard to the Arctic should be concerned.

Occurrence of selected endocrine disrupting compounds in Iberian coastal areas and assessment of the environmental risk

The spatial and temporal distribution of selected endocrine disrupting compounds (4-tert-octylphenol, 4-n-octylphenol, 4-n-nonylphenol, nonylphenol, and bisphenol A) in two coastal areas of the Iberian Peninsula (Ria de Vigo and Mar Menor lagoon) were evaluated for the first time. Seawater and sediment samples collected during spring and autumn of 2015 were analysed using greener extraction techniques and liquid chromatography-tandem mass spectrometry. The presence of branched isomers (4-tert-octylphenol and nonylphenol) and bisphenol A in almost all seawater and sediment samples demonstrated their importance as pollutants in the frame of water policy, while no concentrations of linear isomers (4-n-octylphenol and 4-n-nonylphenol) were found. Higher seawater levels were observed in Mar Menor lagoon, especially in spring, associated with wastewater treatment plant effluents and nautical, agricultural and industrial activities. Similar sediment concentrations were measured in both studied areas, being nonylphenol levels five times higher than those measured for the other EDCs. Experimental sediment-water partition coefficients showed a moderate sorption of target compounds to sediments. Risk quotients for water compartment evidenced a moderate risk posed by nonylphenol, considering the worst-case scenario. For sediments, moderate risk related to 4-tert-octylphenol and high risk to nonylphenol were estimated.

Study of possible association between endometriosis and phthalate and bisphenol A by biomarkers analysis

Endocrine disrupting chemicals (EDCs) such as phthalates and bisphenol A (BPA) are substances that may interfere with the actions of endogenous hormones and may be associated with estrogen-related diseases such as endometriosis. This paper describes a case-control study to evaluate the relationship between endometriosis and phthalates and BPA exposure, through biomarkers analysis in urine. The biomarkers of exposure analyzed were metabolites mono-methyl phthalate, mono-isobutyl phthalate (MiBP), mono-butyl phthalate, mono-cyclohexyl phthalate, mono-(ethylhexyl) phthalate, mono-isononyl phthalate, mono-octyl phthalate (MOP), mono-benzyl phthalate and BPA. Urine samples were collected from women aged 18-45 years old. The Study group (n = 30) and Control group (n = 22) were composed of women using as criteria confirmation of endometriosis by videolaparoscopy surgery with histological diagnosis and the absence of the disease, respectively. The analytical method used liquid phase microextraction with determination by gas chromatography coupled to mass spectrometry. The concentrations of biomarkers were adjusted by the creatinine concentration in urine samples of the two groups. The values obtained for the Study Group were compared with the values obtained for the Control Group. The chi-square test and Odds Ratio were used to compare dichotomized phthalate metabolites and BPA metabolite by endometriosis. All nine metabolites were found in different concentrations in the urine samples in both groups The phthalate metabolites that had the highest concentrations, were MOP and MiBP, in which the values of 670 μg g^-1 and 560 μg g^-1, respectively. The relationship between endometriosis and the all grouped metabolites was evaluated, but was not statistically significant with a 95% CI [X² (df = 1) = 1.471; p = 0.225]. However, odds ratio (95% confidence interval - CI) for MiBP, which was found at relatively high concentrations in the samples, by endometriosis was 1.929 (0.507-7.332). The food habits and gynecologic history were evaluated and no difference was found between groups. Although no evidences of causal link was found, this study contributes to show that other analysis must be done for evaluating the association between endometriosis and compounds suspected of being EDC.

Novel generation of deep eutectic solvent as an acceptor phase in three-phase hollow fiber liquid phase microextraction for extraction and preconcentration of steroidal hormones from biological fluids

In this study, a novel generation of deep eutectic solvents (DESs) was used as an acceptor phase in three-phase hollow fiber liquid phase microextraction (HF-LPME) based on two immiscible organic phases. It was compared with other common DESs for extraction and preconcentration of dydrogesterone (DYD) and cyproterone acetate (CPA) from urine and plasma samples. The extracted analytes were analyzed by high performance liquid chromatography with UV-vis detector (HPLC-UV). This phosphonium based DES due to low volatility, low price and multifunctionality introduced itself as worthy next generation of acceptor phase in HF-LPME. The factors affected on extraction efficiency of the analytes were investigated and optimized. The performance of the proposed method was studied in terms of linear ranges (LRs from 1 to 500µgL^-1 with R² ≥ 0.9946), precision (RSD% ≤ 6.3) and limits of detection (LODs in the range of 0.5-2µgL^-1). Under the optimized conditions, preconcentration factors in the range of 187-428 were obtained. Finally, the method was applied to the analysis of DYD and CPA in human urine and plasma samples and desirable results were obtained.

Simultaneous determination of estrogenic odorant alkylphenols, chlorophenols, and their derivatives in water using online headspace solid phase microextraction coupled with gas chromatography-mass spectrometry

A simple online headspace solid-phase microextraction (HS-SPME) coupled with the gas chromatography-mass spectrometry (GC-MS) method was developed for simultaneous determination of trace amounts of nine estrogenic odorant alkylphenols and chlorophenols and their derivatives in water samples. The extraction conditions of HS-SPME were optimized including fiber selection, extraction temperature, extraction time, and salt concentration. Results showed that divinylbenzene/Carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber was the most appropriate one among the three selected commercial fibers, and the optimal extraction temperature, time, and salt concentration were 70 °C, 30 min, and 0.25 g/mL, respectively. The developed method was validated and showed good linearity (R (2) > 0.989), low limit of detection (LOD, 0.002-0.5 μg/L), and excellent recoveries (76-126 %) with low relative standard deviation (RSD, 0.7-12.9 %). The developed method was finally applied to two surface water samples and some of these target compounds were detected. All these detected compounds were below their odor thresholds, except for 2,4,6-TCAS and 2,4,6-TBAS wherein their concentrations were near their odor thresholds. However, in the two surface water samples, these detected compounds contributed to a certain amount of estrogenicity, which seemed to suggest that more attention should be paid to the issue of estrogenicity rather than to the odor problem.

Analytical methods for the endocrine disruptor compounds determination in environmental water samples

The potential risk of exposure to different xenobiotics, which can modulate the endocrine system and represent a treat for the wellness of an increasing number of people, has recently drawn the attention of international environmental and health agencies. Several agents, characterized by structural diversity, may interfer with the normal endocrine functions that regulate cell growth, homeostasis and development. Substances such as pesticides, herbicides, plasticizers, metals, etc. having endocrine activity (EDCs) are used in agriculture and industry and are also used as drugs for humans and animals. A difficulty in the analytical determination of these substances is the complexity of the matrix in which they are present. In fact, the samples most frequently analyzed consist of groundwater and surface water, including influent and effluent of wastewater treatment plants and drinking water. In this review, several sample pretreatment protocols, assays and different instrumental techniques recently used in the EDCs determination have been considered. This review concludes with a paragraph in which the most recent hyphenated-instrument techniques are treated, highlighting their sensitivity and selectivity for the analyses of environmental water samples.

Activated carbons impregnated with iron oxide nanoparticles for enhanced removal of bisphenol A and natural organic matter

The removal of bisphenol A (BPA) is important for the provision of safe drinking water, but its removal in the presence of natural organic matter (NOM) is challenging. Thus, the present study involved the fabrication and characterization of powdered activated carbons impregnated with iron oxide nanoparticles (IONPACs) with respect to the simultaneous removal of BPA and NOM. The number of Fe ions loaded into the PAC pores was optimized in terms of exposure time. Impregnation with iron oxide reduced the surface area and pore volume, but the pore size was maintained. IONPAC adsorbents had considerably greater sorption capabilities for BPA and NOM compared to native, bare PAC particles. The adsorption capacities of BPA and NOM were in the following sequence: bare PAC<hematite/PAC < magnetite/PAC < ferrihydrite/PAC. The enhanced removal by IONPACs was attributable to the surface coordination between the functional groups in the iron oxides (e.g., hydroxyl groups) and organics (e.g., phenolic/carboxyl groups). Iron oxide impregnation enabled the BPA uptake to be maintained in the presence of NOM, indicating that the hybrid adsorbent provided synergistic adsorption characteristics for BPA and NOM. Although the solution pH had a negligible impact on BPA uptake, the ionic strength showed a significant effect, particularly in the presence of divalent Ca ions.

Development and validation of a liquid chromatography isotope dilution mass spectrometry method for the reliable quantification of alkylphenols in environmental water samples by isotope pattern deconvolution

We present here a new measurement method for the rapid extraction and accurate quantification of technical nonylphenol (NP) and 4-t-octylphenol (OP) in complex matrix water samples by UHPLC-ESI-MS/MS. The extraction of both compounds is achieved in 30min by means of hollow fiber liquid phase microextraction (HF-LPME) using 1-octanol as acceptor phase, which provides an enrichment (preconcentration) factor of 800. On the other hand we have developed a quantification method based on isotope dilution mass spectrometry (IDMS) and singly (13)C1-labeled compounds. To this end the minimal labeled (13)C1-4-(3,6-dimethyl-3-heptyl)-phenol and (13)C1-t-octylphenol isomers were synthesized, which coelute with the natural compounds and allows the compensation of the matrix effect. The quantification was carried out by using isotope pattern deconvolution (IPD), which permits to obtain the concentration of both compounds without the need to build any calibration graph, reducing the total analysis time. The combination of both extraction and determination techniques have allowed to validate for the first time a HF-LPME methodology at the required levels by legislation achieving limits of quantification of 0.1ngmL(-1) and recoveries within 97-109%. Due to the low cost of HF-LPME and total time consumption, this methodology is ready for implementation in routine analytical laboratories.

Recent advances in application of liquid-based micro-extraction: A review

Liquid-based micro-extraction is a novel “green” sample preparation technique using micro-litre levels of organic solvent to extract target analytes from various sample matrices for subsequent instrumental analysis. This technique developed rapidly from its introduction in the mid-1990s. Micro-extraction methods can be conveniently combined with a wide selection of instruments commonly used in a chemical laboratory; they significantly reduce analysis time and costs of solvents’ use and waste disposal. This review focuses on recent advances in several liquid-based micro-extraction methods, including single-drop micro-extraction, hollow fibre-liquid phase micro-extraction, and dispersive liquid-liquid micro-extraction. Examples of application of these methods to environmental, food, and biomedical analysis are listed.

Hollow fiber liquid-phase microextraction with in situ derivatization combined with gas chromatography-mass spectrometry for the determination of root exudate phenylamine compounds in hot pepper ( Capsicum annuum L.)

Hollow fiber liquid-phase microextraction (HF-LPME) with derivatization was developed for the determination of three root exudate phenylamine compounds in hot pepper ( Capsicum annuum L.) by gas chromatography-mass spectrometry (GC-MS). The performance and applicability of the proposed procedure were evaluated through the extraction of 1-naphthylamine (1-NA), diphenylamine (DPA), and N-phenyl-2- naphthaleneamine (N-P-2-NA) in a recirculating hydroponic solution of hot pepper. Parameters affecting the extraction efficiency were investigated. The calibration curves showed a good linearity in the range of 0.1-10 μg mL(-1). The limits of detection (S/N = 3) for the three compounds were 0.096, 0.074, and 0.057 μg mL(-1), respectively. The enrichment factors reached 174, 196, and 230 at the concentration of 5 μg mL(-1), and relative standard deviations (RSD) of 9.5, 8.6, and 7.8% and 8.4, 7.6, and 6.2% were obtained at concentrations of 2 and 5 μg mL(-1) for 1-NA, DPA, and N-P-2-NA, respectively. Recoveries ranging from 90.2 to 96.1% and RSDs below 9.1% were obtained when HF-LPME with in situ derivatization was applied to determine root exudate 1-NA, DPA, and N-P-2-NA after 15 and 30 days of culture solution, respectively.