Trends in analytical methodologies for the determination of alkylphenols and bisphenol A in water samples

Determination of nine bisphenol analogues in human urine by high-throughput solid-phase extraction and ultra-high performance liquid chromatography-tandem mass spectrometry analysis

Bisphenol analogues (BPs) are a class of typical environmental endocrine-disrupting chemicals (EDCs). This study aimed to establish a highly sensitive and high-throughput method utilizing 96-well solid-phase extraction (96-well SPE) in conjunction with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) employing multiple reaction monitoring (MRM), information-dependent acquisition (IDA), and enhanced product ion (EPI) scan modes for the identification and quantitative analysis of nine BPs in human urine. Urine samples were initially thawed to room temperature, followed by digestion using β-glucuronidase in an ammonium acetate buffer solution at 37 °C overnight. Subsequently, they were purified using 96-well SPE and finally analyzed by UHPLC-MS/MS. The limits of detection (LOD) for the nine BPs ranged from 0.05 μg∙kg-1 to 0.3 μg kg-1. Average recoveries fell within the range of 92.8 % to 111.7 %. Moreover, both the intra-day and inter-day precisions were satisfactory, with relative standard deviations (RSDs) ranging from 2.2 % to 6.7 % and 3.5 % to 6.3 %, respectively. The targets in the samples exhibited a perfect match, with a purity fit value exceeding 70 % from the self-built library. The analytical method developed in this study demonstrates high accuracy and sensitivity. In addition, the MRM-IDA-EPI mode can effectively identifies the target BPs and prevents false positive detection of analytes in the urine.

PPCPs in coastal wastewater treatment plant effluent and uptake by Pacific oysters (Crassostrea gigas): Findings from a laboratory experiment

Municipal wastewater treatment plant (WWTP) effluent is a primary source of pharmaceuticals and personal care products (PPCPs) to the marine environment, as most of these compounds are not fully removed during the treatment process. Continual discharge from WWTPs into coastal areas may act as a stressor by continually exposing organisms to a suite of PPCPs. To quantify organismal exposure to PPCP mixtures, we conducted a 12-week lab experiment that exposed Pacific oysters to effluent from two Oregon coastal WWTPs of different discharge capacities (permitted as <1 million gallons/day and >1 million gallons/day; or < or >3.785 million liters/day) at a dilution of 25 %. Composite samples of weekly collected effluent and a subset of freeze-dried oysters from experiment week 12 were analyzed for PPCPs. Though challenges with food availability inhibited our ability to confidently identify effects of the contaminants on growth and fitness, the experiment allowed us to examine uptake of contaminants from effluent into an estuarine bivalve of commercial importance. We detected 30 PPCPs and three alkylphenols in effluent and 13 PPCPs and four alkylphenols in oyster tissue, indicating high rates of release from secondary treatment and significant potential for marine organism exposure to and uptake of PPCPs in rural coastal areas.

Simultaneous determination of phthalates and bisphenols from plastic bottled water samples by dispersive solid-phase extraction with multiwalled carbon nanotubes and liquid chromatography/atmospheric pressure photoionization/high-resolution mass spectrometry

RATIONALE

Phthalates and bisphenols were reported as endocrine disrupting chemicals and hence a potential threat to human health. Polyethylene terephthalate bottles are being used to store drinking water and the probability of migration of phthalates and bisphenols from the bottles into the water is high. The migration of analytes with respect to different storage conditions need to be studied.

METHOD

A sensitive analytical method for simultaneous determination of seven phthalates and three bisphenols from packaged drinking water was developed using liquid chromatography/atmospheric pressure photoionization/high-resolution mass spectrometry. The analytes were extracted by dispersive solid-phase extraction by multiwalled carbon nanotubes.

RESULTS

The developed method showed linearity from 0.5 to 5000 μg/L with the limit of detection and limit of quantification ranging from 0.5 to 1 μg/L and 1 to 2 μg/L, respectively, for phthalates and bisphenols. The inter- and intraday variations were below 10%. The recoveries were in the range of 79.5% to 112%. The migration of phthalates and bisphenols increased with storage time and temperature. Maximum migration was observed for diisobutyl phthalate of 1209.7 ng/L followed by dibutyl phthalate at 777.8 ng/L on 180 days of analysis at room temperature. Migration of bis(2-ethylhexyl) phthalate was observed to be higher at elevated temperatures, increasing from 14.9 to 514 ng/L. Similarly, migration of bisphenol-A was increased at 45°C. The results were subjected to analysis of variance (ANOVA) studies and the results showed significant variations of phthalates and bisphenols with respect to storage temperature and time.

CONCLUSION

The use of atmospheric pressure photoionization facilitated simultaneous determination of phthalates and bisphenols. The migration of phthalates and bisphenols increased with increasing temperature and storage time. Maximum migration was observed for diethyl, diisobutyl, dibutyl and bis(2-ethylhexyl) phthalates. This may be attributed to the type of plastic, the processing parameters and recycling.

Current progress in treatment technologies for plastic waste (bisphenol A) in aquatic environment: Occurrence, toxicity and remediation mechanisms

Bisphenol-A (BPA) is a type of endocrine disrupting compound (EDC) that is being widely used in the production of polycarbonate and epoxy resins. In the last few years, human exposure to BPA has been extensively high due to the continuous increment in the Annual Growth Rate (AGR) of the BPA global market. The presence and transportation of BPA in the environment could cause serious damage to aquatic life and human health. This paper reviewed the literature on the exposure and toxicity mechanisms of BPA and advanced analytical techniques for the detection of BPA in the environment and human beings. The study indicated that BPA can cause damaging effects on numerous tissues and organs, including the reproductive system, metabolic dysfunction, respiratory system, immune system and central nervous system. On the basis of reported studies on animals, it appears that the exposure of BPA can be carcinogenic and responsible for causing a variety of cancers like ovarian cancer, uterine cancer, prostate cancer, testicular cancer, and liver cancer. This review paper focused mainly on the current progress in BPA removal technologies within last ten years (2012-2022). This paper presents a comprehensive overview of individual removal technologies, including adsorption, photocatalysis/photodegradation, ozonation/advance oxidation, photo-fenton, membranes/nanofilters, and biodegradation, along with removal mechanisms. The extensive literature study shows that each technology has its own removal mechanism and their respective limitations in BPA treatment. In adsorption and membrane separation process, most of BPA has been treated by electrostatic interaction, hydrogen boning and π-π interations mechanism. Whereas in the degradation mechanism, O* and OH* species have played a major role in BPA removal. Some factors could alter the removal potential and efficiency of BPA removal. This review paper will provide a useful guide in providing directions for future investigation to address the problem of BPA-containing wastewater treatment.

Removal of micropollutants through bio-based materials as a transition to circular bioeconomy: Treatment processes involved, perspectives and bottlenecks

The recent increase in micropollutant levels in water bodies is a growing concern globally. The generation of new materials and techniques for wastewater treatment often involves the release of hazardous wastes and the utilization of energy related to it. This can be resolved by the synthesis of bio-based materials through the use of already released wastes and naturally occurring components, adding their value as reusable resources. These bio-based materials find wide applications for micropollutant elimination and energy tapping due to the presence of various functional groups, large surface area, high stability, and reusability. The processes involved in micropollutant elimination through biomaterials generally include adsorption and degradation. These treatment processes are suggested to depend on various operational parameters like pH, temperature, dose, reaction time, presence of other contaminants, ions, etc. in the system, which may influence the process efficiency. Understanding the potential of bio-based materials many steps can be taken towards its large-scale application to upgrade wastewater treatment plants for micropollutant elimination. Furthermore, the recent advances of bio-based materials in energy storage and conversion have widened its scope for implementation in a circular bioeconomy. The bottlenecks towards such a transition and future recommendations are also presented and discussed.

Endocrine disrupting chemicals in the environment: Environmental sources, biological effects, remediation techniques, and perspective

Endocrine disrupting chemicals (EDCs) have been identified as emerging contaminants, which poses a great threat to human health and ecosystem. Pesticides, polycyclic aromatic hydrocarbons, dioxins, brominated flame retardants, steroid hormones and alkylphenols are representative of this type of contaminant, which are closely related to daily life. Unfortunately, many wastewater treatment plants (WWTPs) do not treat EDCs as targets in the normal treatment process, resulting in EDCs entering the environment. Few studies have systematically reviewed the related content of EDCs in terms of occurrence, harm and remediation. For this reason, in this article, the sources and exposure routes of common EDCs are systematically described. The existence of EDCs in the environment is mainly related to human activities (Wastewater discharges and industrial activities). The common hazards of these EDCs are clarified based on available toxicological data. At the same time, the mechanism and effect of some mainstream EDCs remediation technologies (such as adsorption, advanced oxidation, membrane bioreactor, constructed wetland, etc.) are separately mentioned. Moreover, our perspectives are provided for further research of EDCs.

Assessing exposure of the Australian population to microplastics through bottled water consumption

The presence of microplastics in the environment is substantially documented; however, the pathways of dietary exposure to microplastics are not yet well understood. This is the first study to document the presence of microplastics in bottled water sold in Australia from commercial outlets. In total, 16 brands of bottled water (Australian Sourced: n = 11, Imported: n = 5) sold in the two largest supermarkets in Australia were analysed in triplicate (n = 48) for the presence of polyethylene, PE; polystyrene, PS; polypropylene, PP; polyvinyl chloride, PVC; polyethylene terephthalate, PET; polycarbonate, PC; polymethylmethacrylate, PMMA; and polyamide, PA. Microplastics were detected in 94% (n = 15) of the samples, with PP (n = 14, 88%), PET (n = 10, 63%), PA (n = 7, 44%), and PE (n = 6, 38%) the most frequently detected. On average, a litre of bottled water contained 13 ± 19 (St Dev) microplastics, ranging from 0 to 80 microplastics/L. The average size of the microplastics identified in this study was 77 ± 22 μm. It was found that bottled water sourced and packaged overseas contained four times as many microplastics compared to bottled water sourced in Australia. It was estimated that in 2017, 28.3% of the Australian population consumed on average 30.8 L of bottled water; therefore, using the result from this study it is estimated that Australians are exposed to 400 microplastics annually through the consumption of bottled water. To understand the total amount of microplastics that Australians could be exposed to through dietary routes, further work is required to observe the presence of microplastics in other beverages and food.

Overview of Different Modes and Applications of Liquid Phase-Based Microextraction Techniques

Liquid phase-based microextraction techniques (LPµETs) have attracted great attention from the scientific community since their invention and implementation mainly due to their high efficiency, low solvent and sample amount, enhanced selectivity and precision, and good reproducibility for a wide range of analytes. This review explores the different possibilities and applications of LPμETs including dispersive liquid–liquid microextraction (DLLME) and single-drop microextraction (SDME), highlighting its two main approaches, direct immersion-SDME and headspace-SDME, hollow-fiber liquid-phase microextraction (HF-LPME) in its two- and three-phase device modes using the donor–acceptor interactions, and electro membrane extraction (EME). Currently, these LPμETs are used in very different areas of interest, from the environment to food and beverages, pharmaceutical, clinical, and forensic analysis. Several important potential applications of each technique will be reported, highlighting its advantages and drawbacks. Moreover, the use of alternative and efficient “green” extraction solvents including nanostructured supramolecular solvents (SUPRASs, deep eutectic solvents (DES), and ionic liquids (ILs)) will be discussed.

Analysis of alkylphenols, bisphenols and alkylphenol ethoxylates in microbial-fermented functional beverages and bottled water: Optimization of a dispersive liquid-liquid microextraction protocol based on natural hydrophobic deep eutectic solvents

In this work, the analysis of alkylphenols, bisphenols and alkylphenol ethoxylates in bottled waters, kombuchas and water kefir was performed through a vortex-assisted dispersive liquid-liquid microextraction method based on a natural hydrophobic eutectic solvent. For this purpose, mixtures of monoterpenes and fatty acids were employed. Different factors affecting extraction were optimized and the method was validated in terms of matrix effect, linearity, limits of detection and recovery. Recovery values varied between 70.0 and 124.3% (except for 4-tert-butylphenol: 67.0% and 4-n-nonylphenol: 60.8% in water kefir) and limits of detection were in the range 0.10 ng/L - 2.99 µg/L. Finally, 8 bottled waters, 8 kombuchas and 4 water kefirs were analyzed and 4-tert-octylphenol monoethoxylate was detected in water (20.28 ± 0.99 - 62.08 ± 3.63 µg/L). This is the first application analyzing xenobiotic contaminants in kombucha and water kefir and the first time in which the three types of compounds are simultaneously extracted by dispersive liquid-liquid microextraction.

Methods for the analysis of endocrine disrupting chemicals in selected environmental matrixes

Endocrine disrupting chemicals (EDCs) are heterogenous in structure, chemical and physical properties, and their capacity to partition into various environmental matrixes. In many cases, these chemicals can disrupt the endocrine systems of vertebrate and invertebrate organisms when present at very low concentrations. Therefore, sensitive and varied analytical methods are required to detect these compounds in the environment. This review summarizes the analytical methods and instruments that are most used to monitor for EDCs in selected environmental matrixes. Only those matrixes for which there is a clear link between exposures and endocrine effects are included in this review. Also discussed are emerging methods for sample preparation and advanced analytical instruments that provide greater selectivity and sensitivity.

Analysis of Indirect Biomarkers of Effect after Exposure to Low Doses of Bisphenol A in a Study of Successive Generations of Mice

Simple Summary

Living beings are constantly and inadvertently exposed to a series of environmental and food pollutants, triggering effects on health that are transmitted over generations. Bisphenol A is a compound produced in large amounts world-wide and used in the manufacture of plastic containers and other utensils for daily use. It is an environmental and food pollutant with a demonstrated capacity to produce effects on the health of organisms exposed to it. The objective of our study was to identify possible indirect biomarkers of effect by means of the analysis of the blood biochemistry, and of certain reproductive parameters of animals exposed to Bisphenol A in doses considered to be safe over different generations. Our results did not show any modifications in the reproduction parameters evaluated, such as the duration of the estrous cycle, the size of the litters, or the percentage of the young alive at weaning time. However, they showed that there were alterations in biochemical parameters like glucose, total proteins, and albumin, which could therefore, be regarded as indirect indicators of an early effect of alterations in health caused by this compound.

Abstract

Bisphenol A (BPA) is considered as being an emerging pollutant, to which both animal and human populations are continuously and inadvertently exposed. The identification of indirect biomarkers of effect could be a key factor in determining early adverse outcomes from exposure to low doses of BPA. Thus, this study on mice aims to evaluate and identify indirect biomarkers of effect through the analysis of their blood biochemistry, and of certain reproduction parameters after exposure to different BPA concentrations (0.5, 2, 4, 50, and 100 µg/kg BW/day) in drinking water over generations. Our results showed that there were no modifications in the reproductive parameters evaluated, like estrous cycle duration, litter size, or the percentage of the young alive at reaching the weaning stage, at the exposure levels evaluated. However, there were modifications in the biochemical parameters, e.g., alterations in the glucose levels, that increased significantly (p < 0.05) in the breeders at the higher exposure doses (50 and 100 µg/kg BW/day in F1; 50 µg/kg BW/day in F2 and 100 µg/kg BW/day in F3), that would suggest that the BPA could induce hyperglycemia and its complications in adult animals, probably due to some damage in the pancreas cells; albumin, that increased in the breeders exposed to the highest dose in F1 and F3, inferring possible hepatic alterations. Further, total proteins showed a diminution in their values in F1 and F2, except the group exposed to 100 µg/kg BW/day, whereas in F3 the values of this parameter increased with respect to the control group, this aspect likely being related to a possible hepatic and renal alteration. Based on these results, glucose, albumin, and total proteins could initially be considered as early indicators of indirect effect after prolonged exposure to low BPA doses over generations.

Insights into the Use of Phytoremediation Processes for the Removal of Organic Micropollutants from Water and Wastewater; A Review

Greater awareness of micropollutants present in water and wastewater motivates the search for effective methods of their neutralization. Although their concentration in waters is measured in micro- and nanograms per liter, even at those levels, they may cause serious health consequences for different organisms, including harmful effects on the functioning of the endocrine system of vertebrates. Traditional methods of wastewater treatment, especially biological methods used in municipal wastewater treatment plants, are not sufficiently effective in removing these compounds, which results in their presence in natural waters. The growing interest in phytoremediation using constructed wetlands as a method of wastewater treatment or polishing indicates a need for the evaluation of this process in the context of micropollutant removal. Therefore, the present work presents a systematic review of the effectiveness in the removal of micropollutants from polluted waters by processes based on plant used. The article also analyzes issues related to the impact of micropollutants on the physiological processes of plants as well as changes in general indicators of pollution caused by contact of wastewater with plants. Additionally, it is also the first review of the literature that focuses strictly on the removal of micropollutants through the use of constructed wetlands.

Alkyphenol Exposure Alters Steroidogenesis in Male Lizard Podarcis siculus

BACKGROUND

Nonylphenol (NP) and Octylphenol (OP) are persistent and non-biodegradable environmental contaminants classified as endocrine disruptor chemicals (EDCs). These compounds are widely used in several industrial applications and present estrogen-like properties, which have extensively been studied in aquatic organisms. The present study aimed to verify the interference of these compounds alone, and in mixture, on the reproductive cycle of the male terrestrial vertebrate Podarcis siculus, focusing mainly on the steroidogenesis process.

METHODS

Male lizards have been treated with different injections of both NP and OP alone and in mixture, and evaluation has been carried out using a histological approach.

RESULTS

Results obtained showed that both substances are able to alter both testis histology and localization of key steroidogenic enzymes, such as 3β-hydroxysteroid dehydrogenase (3β-HSD), 17β- hydroxysteroid dehydrogenase (17β-HSD) and P450 aromatase. Moreover, OP exerts a preponderant effect, and the P450 aromatase represents the major target of both chemicals.

CONCLUSIONS

In conclusion, NP and OP inhibit steroidogenesis, which in turn may reduce the reproductive capacity of the specimens.

2,2-Bis(4-Hydroxyphenyl)-1-Propanol-A Persistent Product of Bisphenol A Bio-Oxidation in Fortified Environmental Water, as Identified by HPLC/UV/ESI-MS

Biodegradation of bisphenol A in the environmental waters (lake, river, and sea) has been studied on the base of fortification of the samples taken and the biodegradation products have been analyzed using HPLC/UV/ESI-MS. Analysis of the characteristic fragmentation patterns of [M-H]^- ions permitted unambiguous identification of the biodegradation products as 2,2-bis(4-hydroxyphenyl)-1-propanol or as p-hydroxyacetophenone, depending on the type of surface water source. The formation of 2,2-bis(4-hydroxyphenyl)-1-propanol was much more common than that of p-hydroxyacetophenone. Moreover, 2,2-Bis(4-hydroxyphenyl)-1-propanol has not been further biodegraded, in contrast to the p-hydroxyacetophenone, which was further mineralized. It has been proved, for the first time, that 2,2-bis(4-hydroxyphenyl)-1-propanol can be regarded as persistent product of bisphenol A biodegradation in the fortified environmental waters.

Quantification, removal and potential ecological risk of emerging contaminants in different organic loads of swine wastewater treated by integrated biological reactors

This study aims to evaluate the dynamics and their ecological risks for aquatic species of lipid regulator, nervous stimulant, anti-inflammatory and endocrine disrupters in an upflow anaerobic sludge blanket (UASB), submerged aerated biological filters (SABF) and horizontal subsurface flow constructed wetland (HSSF-CW) reactors that treat swine wastewater. Four organic loads of swine wastewater (SW) were used according to changing the chemical oxygen demand. 13 contaminants were quantified, standing out the endocrine disruptors, lipid regulator and anti-inflammatory. In phase III, 8318.4 ng L^-1 of 4-ocylphenol was found at the influent of the UASB reactor and removal from 1877.1 to 13.7 ng L^-1 in the bisphenol A system. With the maximum organic load, there was a reduction among all the treatment units, with concentrations between 1877.1 and 13.7 ng L^-1 of bisphenol A and had naproxen removal of 94.5% and 2,7 ng L^-1 after treating phases II and III. It was found that 24.6% of the contaminants presented a high ecological risk, with maximum values of 27.4 (4-nonylphenol, phase II), 24.6 and 5.9 (17β-estradiol, phase IV and I, respectively), 13.4 (4-ocylphenol, phase III) and 4.4 (estrone, phase IV) in the influent system. The reduction of ecological risk potentials was optimized by SABF and HSSF-CW. The effect oxygen availability and microbiological activities optimized the reduction of ecological risks on zebrafish (Danio rerio) and cnidarian (Hydra attenuata) species, moreover, the reduction of mass flows and ecological risks of the emerging contaminants are associated with the use of biological reactors in series and organic stabilizations.

Multivariate optimization of low-temperature cleanup followed by dispersive solid-phase extraction for detection of Bisphenol A and benzophenones in infant formula

A simple and effective analytical method to determine six contaminants, including five benzophenones (BP, BP-1, BP-3, BP-8, and BP-12) and bisphenol A (BPA) in infant formulas was developed in this study. For this, a sequential experimental design was used to optimize the extraction and cleanup method using low temperature partition (LTP) combined with dispersive solid phase extraction (dSPE). The effect of primary secondary amine (PSA), sodium chloride (NaCl), graphitized carbon black (GCB), octadecyl (C18), strong anion exchanger (SAX), water, acetonitrile (ACN) and, ultrasound (US) time were evaluated using a sequential design of experiments including a Plackett-Burman, a central composite rotatable design, and the Derringer and Suich's tool. The method was validated, and it showed a limit of quantification varying from 0.06 to 2 mg.kg^-1, good precision (< 20% RSD), and recovery (52-106%). The method proposed was applied to twenty-five samples of commercial infant formulas.

Sample Preparation to Determine Pharmaceutical and Personal Care Products in an All-Water Matrix: Solid Phase Extraction

Pharmaceuticals and personal care products (PPCPs) are abundantly used by people, and some of them are excreted unaltered or as metabolites through urine, with the sewage being the most important source to their release to the environment. These compounds are in almost all types of water (wastewater, surface water, groundwater, etc.) at concentrations ranging from ng/L to µg/L. The isolation and concentration of the PPCPs from water achieves the appropriate sensitivity. This step is mostly based on solid-phase extraction (SPE) but also includes other approaches (dispersive liquid-liquid microextraction (DLLME), buckypaper, SPE using multicartridges, etc.). In this review article, we aim to discuss the procedures employed to extract PPCPs from any type of water sample prior to their determination via an instrumental analytical technique. Furthermore, we put forward not only the merits of the different methods available but also a number of inconsistencies, divergences, weaknesses and disadvantages of the procedures found in literature, as well as the systems proposed to overcome them and to improve the methodology. Environmental applications of the developed techniques are also discussed. The pressing need for new analytical innovations, emerging trends and future prospects was also considered.

Multiresidue method for the determination of high production volume plastic additives in river waters

The aim of this study was to develop a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS)-based method for the multiresidue analysis of 21 plastic additives in river water. Analysed compounds included phthalates, benzophenone, bisphenol A and long- and short-chain alkylphenols (APs), which are of relevance because most of them are high production volume chemicals largely used in the plastic industry. These compounds can reach river waters due to direct discharge from wastewater treatment plants and leaching from plastic materials and microplastics present in rivers. In a first step, ionisation and acquisition parameters were optimised to obtain high sensitivity and structural information. Then, different solid-phase extraction cartridges and elution conditions were tested using Milli-Q and river water. With the optimised conditions, quality control parameters (recoveries, limits of detection, intra- and inter-day variability and blank contribution) proved that the method was accurate and selective for the trace monitoring of these compounds in river water. For nonylphenol, octylphenol and bis(2-ethylhexyl)phthalate, included in the Water Framework Directive, limits of detection were below environmental quality standard concentrations considering blank contributions. All other compounds were efficiently detected at trace levels, and focus was given to o- and p-substituted and di- and tri-substituted APs, which are first reported in the present study. A pilot survey was finally carried out to determine the occurrence of plastic additives in river waters surrounding the city of Barcelona.

Determination of bisphenol A: Old problem, recent creative solutions based on novel materials

Bisphenol A is a synthetic compound widely used in industry, in the production of polycarbonate, epoxy resins, and thermal paper, among others. Its annual production is estimated at millions of tons per year, demonstrating its importance. Despite its wide application in various everyday products, once in the environment (due to its disposal or leaching), it has high toxicity to humans and animal life, and this problem has been well known for years. Given this problem, many researchers seek alternatives for its monitoring in matrices such as natural water, waste, food, and biological matrices. For this, new advanced materials have been developed, characterized, and applied in creative ways for the preparation of samples for the determination of bisphenol A. This article aims to present some of these important and recent applications, describing the use of molecularly imprinted polymers, metal and covalent organic frameworks, ionic liquids and magnetic ionic liquids, and deep eutectic solvents as creative solutions in sample preparation for the long-standing problem of bisphenol A determination.

Permanently Positively Charged Stable Isotope Labeling Agents and Its Application in the Accurate Quantitation of Alkylphenols Migrated from Plastics to Edible Oils

A new permanently positively charged stable isotope labeling (SIL) agent pair, 4-(((2,5-dioxopyrrolidin-1-yl)oxy)carbonyl)-N,N,N-trimethylbenzenaminium iodide(DPTBA) and its deuterated counterpart d₃-DPTBA, was designed and synthesized. The SIL agents were applied to the liquid chromatography-tandem mass spectrometry analysis of alkylphenols. Light labeled standards and heavy labeled samples were mixed and analyzed simultaneously. Matrix effect which mainly occurred during the ionization process was minimized because of the identical ionization processes between samples and standards. Meanwhile, derivatization made alkylphenols be positively charged, and thus the sensitivity was enhanced. The limits of detection were in the range of 1.5-1.8 ng/L, and the limits of quantitation were in the range of 4.8-6.1 ng/L. The developed method was applied to analyze alkylphenols migrated from plastics to edible oils. The recoveries for all analytes were in the range of 88.6-95.3%, while the matrix effects for all analytes were in the range of 96.2-99.6%.

Worldwide bottled water occurrence of emerging contaminants: A review of the recent scientific literature

Contaminants of emerging concern (CECs) have recently been detected in bottled water and have brought about discussions on possible risks for human health. However, a systematic review of CECs in bottled water is currently lacking due to the relatively new introduction and/or detection of these pollutants. Hence, this paper reviews the existing studies on the presence of six major groups of emerging contaminants including microplastics (MPs), pharmaceuticals and personal care products (PPCPs), bisphenol A (BPA), phthalates, alkylphenols (APs), and perfluoroalkyl and polyfluoroalkyl substances (PFASs) in bottled water from different countries. Also, the findings related to CECs' levels, their possible sources, and their risks are summarized. The gathered data indicate that MPs within the size range of 1-5 μm are the most predominant and potentially toxic classes of MPs in bottled water. In addition, PPCPs, PFASs, APs, and BPA occur in concentration levels of ng/L, while phthalates occur in the μg/L level in bottled water. The bottle type plays an important role in the contamination level. As expected, water in plastic bottles with plastic caps is more polluted than in glass bottles. However, other sources of contamination such as contact materials during cleaning, bottling, and storage are not negligible. Based on the gathered data in this review, the CEC levels except for MPs (no threshold values) in bottled water of most countries do not raise a safety concern for the human. However, the occurrence of individual CECs and their association in bottled water need more accurate data to understand their own/synergistic effects on human health.

Determination of Bisphenol A by High-Performance Liquid Chromatography Based on Graphene Magnetic Dispersion Solid Phase Extraction

Bisphenol A (BPA), as one of the environmental endocrine disruptors, is extensively existing and threatening to human health. To evaluate the environmental exposure level and protect human from the hazard of BPA, a precise and sensitive method is established. In this work, Graphene@ Fe3O4 (G@Fe3O4) is prepared by chemical coprecipitation method as magnetic dispersion solid phase extraction (MDSPE) material. The rapid and specific detection method of BPA is carried out by high-performance liquid chromatography (HPLC). Properties of G@Fe3O4 are identified by the fourier infrared spectrum and scanning electron microscopy. Conditions of solid phase extraction are optimized. Under the optimal extraction conditions, G@Fe3O4 has perfect enrichment effect on BPA. There is a good linear relationship in the range of 5.0~1000.0 μg/L with the correlation coefficient of 0.9997. The detection limit is 0.1 μg/L. This method is applied to water samples successfully, and recoveries of BPA are between 88.19% and 99.56% (RSDs < 3.00%). G@Fe3O4 was synthesized, which was used to extract BPA in water samples before HPLC analysis, and has shown perfect extraction ability toward BPA, which indicates that the determination method of BPA by HPLC based on graphene MDSPE is faster and more precise.

Determination of endocrine disruptive phenolic compounds by gas chromatography mass spectrometry after multivariate optimization of switchable liquid-liquid microextraction and assessment of green profile

This study presents an accurate method for the determination of alkyl phenols and bisphenol A at trace levels using gas chromatography mass spectrometry after preconcentration with switchable liquid-liquid microextraction. In order to achieve high extraction output, the environmentally friendly switchable liquid-liquid microextraction method was optimized by varying parameters such as amount of switchable solvent, sodium hydroxide concentration/amount and the mixing period in a Box-Behnken experimental design. Under optimum extraction conditions, the limits of detection calculated for the analytes were between 0.13 and 0.54 ng/mL. The analytes showed good linearity over broad calibration ranges, and low percent relative standard deviations established good precision. Spiked recovery studies were performed on municipal wastewater and tap water to determine the method's suitability and accuracy, and the results (87-106%) obtained were satisfactory. Bisphenol A was detected (4.0-14 ng/mL) in four plastic samples investigated under high temperature conditions.

Integration of black phosphorus and hollow-core anti-resonant fiber enables two-order magnitude enhancement of sensitivity for bisphenol A detection

Hollow core anti-resonant fiber (HARF) has found a handful applications in optical communications, nonlinear optics and high power delivery. The intrinsic property of the fiber also renders it an ideal candidate for biosensing, which has not been explored intensively. Herein, we demonstrate an optical fiber sensing platform, taking advantages of the state-of-the-art HARF technology and superior physicochemical properties of 2D material black phosphorus, for ultra-sensitive detection of bisphenol A (BPA) in blood and environmental samples. The specially designed HARF can not only achieve broadband transmission of light, but also confine light in the low refractive-index liquid core, ensuring maximum overlap of light and liquid core. Modification of the inner surface of HARF with 2D black phosphorus nanoflakes functionalized with fluorescently labeled BPA-specific aptamer provides a smart sensing interface enabling highly selective detection of BPA via measuring the fluorescence. The limit of detection is 1.69pM, which is more than two orders of magnitude enhancement compared to the conventional plate assay. The proposed assay is not interfered with the BPA analogues BPB and BPS. The long optical path with tight optical confinement greatly enhances the analyte-light interaction and improves the sensitivity of the sensing platform. The proposed sensing platform can be further developed for versatile applications.

Removal efficiency and mass balance of polycyclic aromatic hydrocarbons, phthalates, ethoxylated alkylphenols and alkylphenols in a mixed textile-domestic wastewater treatment plant

In this work the occurrence and fate of polycyclic aromatic hydrocarbons (PAHs), phthalic acid esters (PAEs), mono and diethoxylate alkylphenols (AP_1-2EOs) and alkylphenols (APs) have been investigated during a two-weeks period in a facility treating mixed textile-domestic wastewater (Prato, Italy). The wastewater treatment plant (WWTP) consists of primary sedimentation, activated sludge biological oxidation, secondary sedimentation, clariflocculation and ozonation. The sludge is treated within the facility by thickening, dewatering and final incineration, thus providing the almost quantitative removal of the adsorbed micropollutants. Naphthalene (50%), di(2-ethylhexyl) phthalate (74%) and branched 4-nonylphenols (59%) were the individual main representative compounds of each class in the influent wastewater, which showed concentration ranges of 5.6-66, 85-290 and 21-133μg/L for PAHs, PAEs and APs+AP_1-2EOs, respectively. The WWTP efficiently removed PAHs, PAEs and APs+AP_1-2EOs, providing effluent concentrations of 0.075-0.16ng/L 0.38-9.9μg/L and 0.53-1.4μg/L. All targeted priority and priority-hazardous micropollutants showed effluent concentrations in line with the European environmental quality standards (EQS), even though for di(2-ethylhexyl) phthalate and benzo(a)pyrene after correction for the dilution factor of the recipient. The WWTP performance was evaluated by mass balance, verifying its accuracy by monitoring Pb and Cd as conservative species. The biological treatment sections provided mass losses of 85.5%, 74.5% and 56.8% for APs+AP_1-2EOs, PAEs and PAHs, highlighting efficient biotransformation performances of the activated sludge process. However, for the more volatile PAHs (e.g. naphthalene), a significant contribution of stripping cannot be excluded. A remarkable mass loss was also determined in the ozonation stage for PAEs (72.9%) and especially PAHs (97.0%), whereas a lower efficiency was observed for APs+AP_1-2EOs (41.3%). The whole plant allowed for obtaining an almost quantitative removal (96.7-98.4%) for all targeted compounds.

Ecological risks of phenolic endocrine disrupting compounds in an urban tropical river

The distribution of emerging organic contaminants in drinking water sources in Africa is a subject with very scanty data and information. In order to fill knowledge gaps, we report here the distribution and potential ecological risks of three phenolic compounds (bisphenol A (BPA), 4-nonylphenol (NP), and 4-tert-octylphenol (OP)), which have been previously identified to have the potential of endocrine disrupting activity, in surface water and sediment of the New Calabar River. The compounds were quantified using GC-MS. At all sampling sites, a similar concentration pattern of BPA > NP > OP was recorded, with the exception of Choba sampling station in which the levels of these endocrine disrupting compounds were low or undetectable. The levels of BPA in surface water ranged from 1.20 to 63.64 μg/L, whereas those of NP and OP ranged from < 0.20 to 2.15 μg/L and from < 0.10 to 0.68 μg/L, respectively. For sediments, measured levels were from 1.20 to 66.57 μg/kg for BPA, from < 0.35 to 3.37 μg/kg for NP, and from < 0.13 to 0.90 μg/kg for OP. Risk quotients (RQs) assessed for some sensitive organisms (algae, Daphnia magna, and fish) were above 1 for BPA and NP, whereas RQs for OP were below 1. This implies that BPA and NP at the levels detected could have potential risks to the sensitive organisms considered, but low risk for OP.

State-of-the-art on the technique of dispersive liquid-liquid microextraction

Dispersive liquid-liquid microextraction is a new sample pretreatment technology based on traditional liquid liquid extraction. In this paper, the application of low-toxicity extractants such as low-density extractants, auxiliary extractants, stripping agents and ionic liquids in this technology and the extraction modes such as solvent de-emulsification, suspension extractant curing, auxiliary extraction, back extraction, and ionic liquid-dispersion liquid microextraction, are summarized. In addition, the synergism of this technique with other sample preparation techniques, such as liquid-liquid extraction, solid-phase extraction, solid-phase microextraction, dispersive solid phase extraction, matrix solid-phase dispersion extraction, supercritical fluid extraction and ultrasound-assisted dispersive liquid-liquid microextraction is discussed.

Determination of bisphenol A in red wine using a double vortex-ultrasound-assisted microextraction assay: Role of the interfacial properties

Bisphenol A (BPA) is a synthetic compound broadly used in medical devices as well as in packaging of food and drinks. Recently, BPA toxicity has become of concern to environmental public health. Red wine that is susceptible to BPA contamination is an alcoholic beverage made from yeast fermentation of grapes in the presence of grape skins so as to extract phenolic compounds. The aim of this study was to validate an efficient, low cost, and time-saving method for BPA determination in red-wine beverage. To this end, a rapid and simple microextraction method is here proposed consisting in liquid-liquid separation assisted by a vortex-ultrasound-vortex procedure combined with gas chromatographic analysis (GC-Fid or GC-IT/MS). By means of a comparative study between real red-wine matrix and synthetic hydroalcoholic solutions, different parameters related to the microextraction steps were investigated. The minimal amount of extraction solvent for a given volume of sample was calculated for both the systems. It was demonstrated that for red-wine matrix, the extent of phase separation is strongly affected by some wine constituents and that separation can be tuned by varying the amount of the extraction solvent. This double vortex-ultrasound-assisted method achieved high recovery of BPA and enrichment factor compared with other microextraction methods.

Preparation of Molecularly Imprinted Microspheres as Biomimetic Recognition Material for In Situ Adsorption and Selective Chemiluminescence Determination of Bisphenol A

Bisphenol A (BPA) is an endocrine disrupter in environments which can induce abnormal differentiation of reproductive organs by interfering with the action of endogenous gonadal steroid hormones. In this work, the bisphenol A (BPA) molecularly-imprinted microspheres (MIMS) were prepared and used as biomimetic recognition material for in situ adsorption and selective chemiluminescence (CL) determination of BPA. Through non-covalent interaction, the BPA-MIMS was successfully prepared by Pickering emulsion polymerization using a BPA template, 4-vinylpyridine (4-VP) monomer, ethylene glycol dimethacrylate (EGDMA) cross-linker, and a SiO₂ dispersion agent. The characterization of scanning electron microscopy (SEM) and energy-disperse spectroscopy (EDS) showed that the obtained MIMS possessed a regular spherical shape and narrow diameter distribution (25–30 μm). The binding experiment indicated BPA could be adsorbed in situ on the MIMS-packing cell with an apparent maximum amount Q_max of 677.3 μg g⁻¹. Then BPA could be selectively detected by its sensitive inhibition effect on the CL reaction between luminol and periodate (KIO₄), and the inhibition mechanism was discussed to reveal the CL reaction process. The CL intensity was linear to BPA concentrations in two ranges, respectively from 0.5 to 1.5 μg mL⁻¹ with a detection limit of 8.0 ng mL⁻¹ (3σ), and from 1.5 to 15 μg mL⁻¹ with a limit of detection (LOD) of 80 ng mL⁻¹ (3σ). The BPA-MIPMS showed excellent selectivity for BPA adsorption and the proposed CL method has been successfully applied to BPA determination in environmental water samples.

Solid phase extraction with high polarity Carb/PSA as composite fillers prior to UPLC-MS/MS to determine six bisphenols and alkylphenols in trace level hotpot seasoning

The present study reports an ultra high-performance liquid chromatography tandem mass spectrometry method for the simultaneous determination of six bisphenols (bisphenol A, bisphenol B and bisphenol F) and alkylphenols (4-nonylphenol, 4-n-nonylphenol and octylphenol) in hotpot seasoning. Samples were dispersed in n-hexane after addition of internal standards bisphenol A-d₄ and 4-n-nonylphenol-d₄. Sample solutions were then centrifuged, and the supernatants purified using solid phase extraction with high polarity Carb/PSA composite fillers. Six target analytes were separated on a Waters ACQUITY BEH C18 column by gradient elution with methanol and 0.05% ammonium hydroxide in water as the mobile phase, and determined under multiple reactions monitoring mode. The limits of detection and quantitation, matrix effect, recovery and precision of the method were investigated. Results were linear in the concentration range 0.1-250 µg/L for all compounds of interest, with R² > 0.9950. Limits of detection were in the range 0.1-0.4 μg/kg, and limits of quantitation were between 0.5 μg/kg and 1.0 μg/kg. The mean recoveries for negative samples at three spiked concentrations were in the range 87.9%-102.4%, and the intra-day precision and inter-day precision were in the ranges 2.1-8.2% and 4.8-11.2%, respectively. This method is accurate and sensitive, and had good clean-up characteristics, which might apply to screening and quantitation of target bisphenols and alkylphenols in hotpot seasoning.